JP2009201057A - Device and method for decoding control - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for decoding process capable of performing efficient decoding while keeping a receiving quality excellent. <P>SOLUTION: A device for decoding control is equipped with a measuring means for measuring predetermined information from the signal after demapping process of a multilevel modulation signal including the signal from a transmitter; determination means for determining the number of iterations in response to the predetermined information measured by the measuring means as a reference value; and a controlling means for controlling a decoder so as to decode the signal from the transmitter through the number of iterations determined by the determination means. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an iterative decoding technique such as a turbo code.

  The turbo code has a high error correction capability and is used in various transmission fields such as the mobile communication system field.

  The turbo encoder has a configuration in which a first element encoder and a second element encoder are connected in parallel via an interleaver. The information bit sequence input to the turbo encoder is simultaneously sent to the first element encoder and the second element encoder via the interleaver. The first element encoder performs predetermined encoding and outputs a first parity bit sequence. The second element encoder performs predetermined encoding on the information bit sequence rearranged by the interleaver, and outputs a second parity bit sequence. These first and second parity bit sequences are punctured and multiplexed according to the set coding rate, and finally multiplexed with the information bit sequence and output from the turbo encoder as a coded bit sequence. The

  On the other hand, in the turbo decoder, the first element decoder and the second element decoder corresponding to the first element encoder and the second element encoder in the turbo encoder are connected in series with the interleaver and the deinterleaver. Has a connected loop configuration. The received signal sequence (corresponding to the information bit sequence and parity bit sequence) input to the turbo decoder is sent to the second element decoder via the first element decoder and interleaver. In the first element decoder, the received signal sequence is decoded based on the reliability information sequence, and is output as a new reliability information sequence. This reliability information sequence is rearranged together with the received signal sequence in the interleaver in the same manner as the interleaver of the turbo encoder, and is sent to the second element decoder. In the second element decoder, the interleaved received signal sequence is decoded based on the similarly interleaved reliability information sequence, and further output as a new reliability information sequence. The reliability information series output from the second element decoder is returned to the original arrangement order by the deinterleaver, sent to the first element decoder, and then iteratively decoded.

  Thus, turbo decoding is a technique of performing decoding while increasing reliability information between two element decoders. Therefore, by increasing the number of repetitions (hereinafter also referred to as iteration). There is a feature that the error rate can be reduced. On the other hand, this turbo decoding also has a feature that the time required for data decoding increases if the number of iterations is set to increase the communication quality.

Therefore, it is important for the turbo decoder to set an appropriate number of iterations. As a result, a method for reducing the decoding delay and improving the communication quality by controlling the number of times of interaction in the turbo decoder has been proposed (see Patent Documents 1 and 2 below).
JP 2002-152056 A JP 2003-198513 A

  In a conventional turbo decoder, generally, the number of iterations that can realize a desired reception quality and QoS (Quality of Service) under a worst case condition is set in advance.

  Such a technique has appropriate decoding performance for a service sent from a transmission apparatus having a poor reception state, but excessive decoding for a service sent from a transmission apparatus having a good reception state. Will have performance. In other words, it can be said that extra decoding processing time is taken for a service sent from a transmission apparatus in a good reception state. An increase in the decoding processing time also causes a decrease in throughput of the entire system.

  Further, when there are a plurality of services to be controlled for retransmission, each of these services must be further decoded for the total number of retransmissions. If the time required for the turbo decoding process of each service is added, it may be longer than the time allotted to the decoding process in the system, which may adversely affect the reception quality and QoS.

  In view of such problems, the present case provides a decoding processing technique that performs efficient decoding while maintaining good reception quality.

  In each aspect, the following configurations are employed in order to solve the above-described problems.

  The first aspect is a measuring means for measuring predetermined information from a signal after demapping processing of a multi-level modulation signal including a signal from a transmitting apparatus, and the predetermined information measured by the measuring means as an index value. Decoding control comprising: determining means for determining the number of iterations corresponding to information; and control means for controlling the decoder so that the signal from the transmission device is decoded with the number of iterations determined by the determining means Device.

  In this first aspect, predetermined information is measured from the signal after the demapping process of the multilevel modulation signal, and the signal from the transmission device is decoded based on the number of iterations determined based on this measurement information. Here, the demapping process means a process of converting a multi-value modulated symbol sequence signal into a bit sequence signal, and is also called a symbol-bit mapping process. As the predetermined information, for example, throughput, BLER (Block Error Rate), number of retransmissions, and the like are used.

  The measurement information obtained from the signal after the demapping process includes the propagation environment between the transmitter and the signal processing up to the demapping process in the receiver in which the decoding control device according to the first aspect is mounted. Each circuit characteristic is reflected.

  Therefore, according to this first aspect, since the number of iterations is determined based on such measurement information, an appropriate number of iterations according to the communication situation actually performed with the transmission device is determined. Can be determined. Furthermore, since turbo decoding is performed by using such an appropriate number of iterations, it is possible to realize efficient decoding that saves unnecessary decoding processing time while maintaining good reception quality.

  Preferably, in the first aspect, the measurement unit uses a signal after the signal after the demapping process is decoded by the decoder, and obtains predetermined information according to the inspection result of the signal after the decoding by the inspector. Configure to measure.

  According to this aspect, the predetermined information to be measured also reflects the characteristics of the decoder and the checker, so that it is possible to determine the number of iterations corresponding to a more precise communication situation.

  Therefore, according to this aspect, it is possible to realize more efficient decoding.

  Preferably, in the first aspect, the measuring unit measures predetermined information according to a test result of the tester and a soft decision signal level of the signal after the demapping process, and the determining unit is configured to perform the predetermined process. The number of iterations corresponding to the index value obtained by multiplying the information and the soft decision signal level by each weighting factor is determined.

  In this aspect, information corresponding to the check result after decoding by the decoder and the soft decision signal level are measured. For each weighting factor multiplied by each measurement information, for example, a value corresponding to the performance and accuracy of a measurement circuit (functional unit) for obtaining each measurement information is set. The number of iterations is determined from the index value obtained from each measurement information and each weighting factor.

  Therefore, according to this aspect, since it is possible to determine the number of iterations according to a more precise communication situation, it is possible to achieve efficient decoding without wasteful decoding processing time while maintaining good reception quality. Can do.

  In the first aspect, the measurement unit may measure only the soft decision signal level, and the number of iterations corresponding to the soft decision signal level may be determined.

  Preferably, in the first aspect, the determination unit is set to be smaller than the quality emphasis table in which the index value is associated with the number of iterations, and the number of iterations corresponding to the same index value is set to be large. A speed emphasis table, a service type included in the signal after the demapping process and serving as a decoding unit of the decoder is discriminated, and a quality emphasis table and a speed emphasis table according to the service type The number of iterations corresponding to the index value is determined by referring to one of the above.

  In this aspect, the number of iterations corresponding to the type of service is determined for each service included in the signal after the demapping process. For example, even if the same index value is obtained, a large number of iterations are assigned to a service that requires real-time service type such as voice or video, and the service type is packet communication or the like. A small number of iterations is assigned to a service where processing speed is important.

  Therefore, according to such an aspect, it is possible to determine an appropriate number of iterations in consideration of QoS in addition to actual communication conditions such as propagation environment and device circuit characteristics.

  Preferably, in the first aspect, when it is determined that the decoding processing time per unit time required for the decoding processing using the number of iterations determined by the determining means exceeds the time limit per unit time, the number of iterations The control means is further configured to control the decoder so that the signal from the transmission device is decoded with the number of iterations corrected by the correction means.

  In this aspect, the number of iterations determined in a manner that reflects the actual communication status is corrected based on the determination result of whether or not decoding processing within the decoding processing time limit determined per unit time is possible. Is done. For example, when it is determined that the time limit is exceeded when the decoding process is actually performed with the determined number of iterations, the number of iterations is decreased.

  According to such an aspect, since the number of iterations is determined in consideration of the time required for the decoding process in addition to the communication status, it is possible to suppress a decrease in throughput due to an increase in the decoding process time.

  As another aspect, it may be a receiving device equipped with the decoding control device as described above, or a decoding control method for realizing any of the above functions on a computer, an IC chip, or the like, It may be a program that realizes any of the functions described above, or a computer-readable storage medium that records such a program.

  According to the disclosed embodiment, it is possible to provide a decoding processing technique that performs efficient decoding while maintaining good reception quality.

  Hereinafter, the receiving apparatus according to the present embodiment will be described with reference to the drawings. The configuration of each embodiment shown below is an exemplification, and the present invention is not limited to the configuration of each embodiment below.

[First embodiment]
Hereinafter, the receiving device 1 in the first embodiment will be described with reference to the drawings.

〔Device configuration〕
Hereinafter, the device configuration of the receiving device 1 in the first embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing a part of the functional configuration of the receiving device 1 in the first embodiment. The receiving apparatus 1 in the first embodiment includes an antenna 10, a radio receiving unit 11, a demodulating unit 12, a turbo decoder 14, a checking unit 15, a throughput measuring unit 16, an iteration count determining unit 17, a decoding control unit 18, and the like. . Each functional unit of the receiving device 1 is realized as a software component, a hardware component, or a combination thereof (see [Others]). Hereafter, each function part which comprises these receivers 1 is each demonstrated.

  The wireless reception unit 11 performs frequency conversion, amplification, and the like on the high-frequency reception signal transmitted from the antenna 10. Further, the wireless reception unit 11 converts the analog reception signal processed in this way into a digital baseband signal, and sends the converted digital baseband signal to the demodulation unit 12.

  The demodulation unit 12 multiplexes and demodulates the digital baseband signal sent from the wireless reception unit 11 corresponding to a modulation scheme such as CDMA (Code Division Multiple Access) or OFDM (Orthogonal Frequency Division Multiplexing), and performs correction based on the channel estimation value. Or detect. The demodulator 12 performs symbol-bit mapping processing (corresponding to demapping processing) on the multilevel modulation signal that has been subjected to correction and the like. The demodulator 12 sends a signal (hereinafter referred to as a received signal sequence) obtained by this symbol-bit mapping process to the turbo decoder 14.

  The turbo decoder 14 has a configuration as described in the background art section, and iteratively decodes an input received signal sequence based on decoding parameters such as the number of iterations set by the decoding control unit 18. I do. The turbo decoder 14 sends the received data sequence obtained as a result of the iterative decoding to the checking unit 15. The received signal sequence is sequentially input to the turbo decoder 14 for each service of the transmission apparatus of the communication partner, decoded for each service, and sequentially output. A service here has a form distinguished in terms of communication, such as voice, video, and data packet, and indicates a decoding processing unit. Further, in the present embodiment, the transmission device itself as a communication partner is not limited, but in the following description, for convenience of description, it is expressed as UE (User Equipment).

The inspection unit 15 inspects the received data series output from the turbo decoder 14. For this inspection, for example, CRC (Cyclic Redundancy Check) is used. In this case, inspection unit 1
5 performs inspection using the CRC bits added to each transport block. The inspection unit 15 outputs the received data series determined to be normal by this inspection. This received data series is processed by another functional unit (not shown). On the other hand, if the inspection unit 15 determines that there is an abnormality by this inspection, the inspection unit 15 notifies other function units (not shown) to that effect for retransmission control or the like.

  The throughput measuring unit 16 monitors the data amount of the received data series output from the inspection unit 15 and measures the throughput based on this data amount. The reception data series output from the inspection unit 15 is arranged for each service as described above. Thereby, the throughput measuring unit 16 measures the throughput in units of UEs by monitoring the received data series in units of UEs that are transmission sources of the service. This throughput is measured, for example, as bits per second (bps). Throughput information measured by the throughput measuring unit 16 is sent to the iteration number determining unit 17.

  Further, the throughput measuring unit 16 also sends the measurement time of the throughput information to the iteration number determining unit 17 in order to determine the accuracy of the throughput information. Since the throughput measurement unit 16 measures the throughput in units of UE, the measurement time is also measured in units of UE. This measurement time is reset by a predetermined blank period.

  The iteration number determination unit 17 determines the number of iterations for each UE based on the throughput information sent from the throughput measurement unit 16. The iteration number determination unit 17 holds a table as shown in FIG. The iteration count determination unit 17 extracts the iteration count corresponding to the index value from the iteration count determination table using the throughput information as an index value.

  FIG. 2 is a diagram illustrating an example of the iteration count determination table. This table stores the number of iterations associated with each range of index values. The number of records in this table and the threshold values (X1 to X15) for determining each range are determined in advance by simulation according to the characteristics of the receiving circuit provided in the receiving device, and are held in an adjustable manner. This table is set so that the number of iterations increases as the throughput is slower (lower). This is based on the fact that when the throughput is slow, retransmission control or the like is performed and it is judged that the reception quality is poor, and it is necessary to improve the decoding performance. Note that the present embodiment does not limit the thresholds and the number of records set in the iteration count determination table, and it is sufficient that appropriate values are set according to the receiving apparatus.

  The iteration number determination unit 17 determines the accuracy of the throughput information based on the measurement time of the throughput information sent from the throughput measurement unit 16 when determining the number of iterations. The accuracy of the throughput information indicates whether or not the throughput information is measured over a period of time that can sufficiently determine the reception state. The iteration count determination unit 17 holds a threshold of measurement time at which it can be determined that the accuracy of the throughput information is sufficient.

  The iteration count determination unit 17 determines that the accuracy of the throughput information is sufficient if the measurement time of the throughput information is equal to or greater than the threshold, and uses the throughput information as an index value. On the other hand, if the measurement time of the throughput information is shorter than the threshold value, the iteration count determination unit 17 determines that the accuracy of the throughput information is not sufficient and determines an initial value as the iteration count. This initial value is also held adjustable.

The decoding control unit 18 sets the number of iterations sent from the iteration number determination unit 17 in the turbo decoder 14. The setting of the number of iterations is realized by ON / OFF control of a switch provided in a loop circuit for iterative decoding in the turbo decoder 14, for example. The decoding control unit 18 notifies the decoding parameters such as the number of services in the TTI to be decoded, the UE information of the transmission source of each service, the data amount of each service from other functional units (not shown) or a predetermined amount Grasp by referring to the data. In the present embodiment, the method of receiving the decoding parameters that the decoding control unit 18 should grasp is not limited.

  The decoding control unit 18 recognizes the UE that is the transmission source of the service to be decoded, and sets the number of iterations determined by the iteration number determination unit 17 for the UE in the turbo decoder 14. This iteration count setting process is switched for each service to be decoded. Similarly, the decoding control unit 18 sets other decoding parameters other than the number of iterations to the turbo decoder 14 as necessary.

[Operation example]
Hereinafter, an operation example of the receiving apparatus 1 in the first embodiment will be described with reference to FIG. FIG. 3 is a flowchart showing an operation example of the receiving device 1 in the first embodiment.

  The high frequency signal received by the antenna 10 is converted into a digital baseband signal by the wireless reception unit 11 and sent to the demodulation unit 12. The demodulator 12 performs multiplexing demodulation, symbol-bit mapping processing, and the like on the input digital baseband signal (S301). The demodulator 12 sends the received signal sequence obtained by such processing to the turbo decoder 14.

  The decoding control unit 18 monitors each received signal sequence input to the turbo decoder 14 and controls the turbo decoder 14 to decode in units of UE services. The decoding control unit 18 initializes (for example, sets to zero) a variable N for the number of services when starting a decoding process of a TTI (Transmission Time Interval) to be processed (S303). At the same time, the decoding control unit 18 recognizes the total number of services included in the TTI to be processed. This is used in the processing of (S311) described later. Subsequently, the decoding control unit 18 counts up the number of decoding processing services (N) (S304), and requests the iteration number determination unit 17 for the number of iterations of the UE that is the transmission source of the current decoding target service. To do.

  In response to this request, the iteration count determining unit 17 refers to the throughput information of the target UE sent from the throughput measuring unit 16 and its measurement time. The iteration number determination unit 17 checks the accuracy of the throughput information by comparing the measurement time with a threshold value stored in advance (S305). The iteration count determination unit 17 determines that the accuracy of the throughput information is sufficient when the measurement time is equal to or greater than the threshold (S305; YES), and uses the throughput information as an index value to determine the iteration count determination table. The number of iterations corresponding to the index value is extracted (S306).

  On the other hand, if the measurement time is shorter than the threshold, the iteration count determination unit 17 determines that the accuracy of the throughput information is not sufficient (S305; NO), and determines the iteration count as an initial value held in advance. (S307). The iteration count determination unit 17 sends the iteration count determined in this way to the decoding control unit 18.

  The decoding control unit 18 sets the number of iterations sent from the iteration number determination unit 17 in the turbo decoder 14.

  The turbo decoder 14 decodes the received signal sequence in service units based on the decoding parameters sent from the decoding control unit 18. At this time, the turbo decoder 14 repeatedly decodes the number of iterations set by the decoding control unit 18 (S308). The received data series (service) subjected to the iterative decoding is sent to the inspection unit 15.

  The inspection unit 15 sequentially inspects the input received data series. The received data series that have been inspected by the inspecting unit 15 and determined to be normal are sequentially output.

  The throughput measuring unit 16 monitors the received data series arranged for each service output from the inspecting unit 15, and measures the throughput for each UE based on this data amount (S309). At the same time, the throughput measurement unit 16 measures the throughput measurement time for the UE. The throughput measurement unit 16 sends the obtained throughput information and measurement time to the iteration number determination unit 17.

  The decoding control unit 18 monitors the service for which decoding has been completed in the turbo decoder 14 (S311). The decryption control unit 18 determines that the number of decryption processing services (N) counted up in step S304 is less than the total number of services included in the TTI, that is, there is a service that has not yet been decrypted in the TTI to be processed. If it judges (S311; NO), it will return to process S304 and will perform the decoding process similar to the above regarding the next service.

  When the decoding process is completed for all services in the TTI to be processed (S311; YES), the decoding control unit 18 determines whether there is a next received signal sequence (S312). When the decoding control unit 18 determines that the next received signal sequence exists (S312; YES), the decoding control unit 18 starts decoding processing in the next TTI (S301).

<Operation and effect in the first embodiment>
As described above, in the receiving apparatus in the first embodiment, the throughput of each UE is measured based on the received data sequence decoded by the turbo decoder 14 and inspected by the inspecting unit 15 (throughput measuring unit). 16).

  The iteration number determination unit 17 that receives the information of the measured throughput holds an iteration number determination table in which the number of iterations corresponding to the throughput is set. This table is used to iterate for the target UE so that if the throughput is high (if it is early), the number of iterations decreases, and if the throughput is low (if it is slow), the number of iterations increases. The number of times is determined. In other words, the number of iterations is determined based on the difference from the target value of the throughput or the achievement rate with respect to the target value based on the measurement result of the throughput.

  As a result, iterative decoding at the turbo decoder 14 is executed with the number of iterations determined according to this throughput. The throughput used for determining the number of iterations is communication result information including all of the propagation environment between the target UE and the receiving device 1, the performance and characteristics of the circuit included in the receiving device 1.

  Therefore, according to the first embodiment, it is possible to determine an appropriate number of iterations according to the communication situation actually performed for each UE. Therefore, since this appropriate number of iterations is used to perform turbo decoding, it is possible to achieve efficient decoding that saves unnecessary decoding processing time while maintaining good reception quality for each UE. it can. Thereby, since the decoding processing time can be shortened, the throughput of the entire system can be improved.

[Second Embodiment]
Next, the receiving device 1 in the second embodiment will be described with reference to the drawings.

〔Device configuration〕
Hereinafter, the device configuration of the receiving device 1 in the second embodiment will be described with reference to FIG. FIG. 4 is a block diagram showing a part of the functional configuration of the receiving device 1 in the second embodiment. The receiving device 1 in the second embodiment differs from the first embodiment only in that a BLER (BLock Error Rate) measuring unit 41 is replaced with a throughput measuring unit 16. That is, other functional units included in the receiving device 1 in the second embodiment are the same as those in the first embodiment, and thus the description thereof is omitted here. The BLER measurement unit 41 is also realized as a software component, a hardware component, or a combination thereof (see [Others]).

  The BLER measurement unit 41 measures BLER in UE units. BLER indicates the ratio between the number of transport blocks in a certain period and the number of transport blocks that have a CRC error. In this measurement, the BLER measurement unit 41 uses the number of transport blocks processed by the inspection unit 15 and the number of transport blocks that have a CRC error, which are sent from the inspection unit 15. The BLER measurement unit 41 sends the measured BLER information to the iteration number determination unit 17. At this time, the BLER measurement unit 41 sends the BLER measurement time together with the BLER information to the iteration count determination unit 17. The measurement time is the same as that measured by the throughput measuring unit 16 in the first embodiment.

  The iteration number determination unit 17 holds the iteration number determination table shown in FIG. 2 as in the first embodiment. BLER indicates that the larger the value, the worse the reception quality, and the smaller the value, the better the reception quality. Therefore, the iteration count determination table in the second embodiment is set such that the greater the BLER value, the greater the iteration count, and the smaller the BLER value, the fewer iteration counts.

  The iteration count determination unit 17 uses the BLER information sent from the BLER measurement unit 41 as an index value, and extracts the iteration count corresponding to this index value from the iteration count determination table. When determining the number of iterations, the iteration number determination unit 17 determines the accuracy of the BLER information based on the measurement time, as in the first embodiment. If the iteration count determining unit 17 determines that the BLER accuracy is sufficient, the iteration count determining unit 17 sends the iteration count extracted from the iteration count determining table to the decoding control unit 18 and determines that the BLER accuracy is insufficient. The initial value is sent to the decoding control unit 18 as the number of iterations.

[Operation example]
The operation example of the receiving device 1 in the second embodiment is the same as that in the first embodiment except that the process S309 in the operation example of the first embodiment shown in FIG. 3 is replaced with the BLER measurement process.

<Operation and effect in the second embodiment>
As described above, in the receiving device 1 in the second embodiment, the BLER of each UE is measured based on the check result in the check unit 15 for the received data sequence decoded and output by the turbo decoder 14. (BLER measurement unit 41).

  The iteration number determination unit 17 that receives the measured BLER information refers to an iteration number determination table in which the number of iterations corresponding to the BLER value is set. Accordingly, the number of iterations for the target UE is determined so that the number of iterations increases if the BLER value is large and the number of iterations decreases if the BLER value is small.

As a result, iterative decoding at the turbo decoder 14 is executed based on the number of iterations determined based on the BLER value. Similar to the throughput information in the first embodiment, the BLER information used for determining the number of iterations includes all of the propagation environment between the target UE and the receiving device 1, the performance and characteristics of the circuit included in the receiving device 1. Communication result information included.

  Therefore, also in the second embodiment, similarly to the first embodiment, it is possible to determine an appropriate number of iterations according to the communication situation actually performed for each UE, and according to each UE, respectively. While maintaining good reception quality, efficient decoding can be realized without wasteful decoding processing time.

[Third embodiment]
Next, the receiving device 1 in the third embodiment will be described with reference to the drawings.

〔Device configuration〕
Hereinafter, the device configuration of the receiving device 1 in the third embodiment will be described with reference to FIG. FIG. 5 is a block diagram illustrating a part of the functional configuration of the receiving device 1 according to the third embodiment. The receiving apparatus 1 in the third embodiment is different from the first embodiment only in that the retransmission number measuring unit 51 is replaced with the throughput measuring unit 16 and the iteration number determining method by the iteration number determining unit 17 is different. That is, other functional units included in the receiving device 1 in the third embodiment are the same as those in the first embodiment, and thus the description thereof is omitted here. The retransmission count measuring unit 51 is also realized as a software component, a hardware component, or a combination thereof (see [Others]).

  The retransmission number measurement unit 51 measures the average number of retransmissions for each UE. The average number of retransmissions indicates the number of times a retransmission instruction is issued to the target UE during a certain period. In this measurement, the retransmission count measurement unit 51 uses a CRC error notification sent from the inspection unit 15. When the inspection unit 15 in the third embodiment determines that the abnormality is found by the inspection, the inspection unit 15 notifies other function units (not shown) to that effect for retransmission control and the like, and the retransmission number measurement unit 51 Also send the notice. The retransmission number measurement unit 51 sends the measured average number of retransmissions to the iteration number determination unit 17. At this time, the retransmission number measurement unit 51 sends the measurement time together with the average number of retransmissions to the iteration number determination unit 17. The measurement time is the same as that measured by the throughput measuring unit 16 in the first embodiment.

  The iteration count determination unit 17 determines the accuracy of the measurement value of the average retransmission count as in the first embodiment, and sets the iteration count to a predetermined initial value if this accuracy is poor. If the iteration count determination unit 17 in the third embodiment determines that the accuracy of the measurement value of the average retransmission count is sufficient, the iteration count determination section 17 compares the target retransmission count held in advance and the average retransmission count. Determine the number of iterations.

  Specifically, if the average number of retransmissions is greater than the target number of retransmissions, the iteration number determination unit 17 increases the number of iterations previously determined for the target UE by one. On the other hand, when the average number of retransmissions is smaller than the target number of retransmissions, the iteration number determination unit 17 decreases the number of iterations previously determined for the target UE by one. This target number of retransmissions is derived in advance by simulation from the feedback processing delay at the MAC level. Note that the iteration count determination unit 17 may extract the iteration count from the iteration count determination table using the average number of retransmissions as an index value, as in the first embodiment. The number of iterations determined in this way is sent to the decoding control unit 18.

[Operation example]
In the operation example of the receiving apparatus 1 in the third embodiment, the process S309 in the operation example of the first embodiment shown in FIG. This is the same as the first embodiment except that the number of iterations is determined by comparison with the number of times.

<Operation and effect in the third embodiment>
As described above, in the receiving apparatus in the third embodiment, the average number of retransmissions of each UE is measured based on the inspection result in the inspection unit 15 for the received data sequence decoded and output by the turbo decoder 14. (Retransmission count measurement unit 51).

  The iteration number determination unit 17 that receives information on the measured average number of retransmissions holds the target number of retransmissions, and compares the target number of retransmissions with the average number of retransmissions as an index value. Is determined by increasing or decreasing the previous value. Thereby, the number of iterations for the target UE is determined so that the number of iterations increases when the average number of retransmissions is large, and the number of iterations decreases when the average number of retransmissions is small.

  As a result, iterative decoding at the turbo decoder 14 is executed with the number of iterations determined based on the average number of retransmissions in this way. Similar to the throughput information in the first embodiment, the average number of retransmissions used for determining the number of iterations depends on the propagation environment between the target UE and the receiving device 1, the performance and characteristics of the circuit included in the receiving device 1. This is communication result information including all.

  Therefore, also in the third embodiment, the same effect as the first embodiment can be obtained.

[Fourth embodiment]
Next, the receiving device 1 in the fourth embodiment will be described with reference to the drawings.

〔Device configuration〕
Hereinafter, the device configuration of the receiving device 1 in the fourth embodiment will be described with reference to FIG. FIG. 6 is a block diagram illustrating a part of the functional configuration of the receiving device 1 according to the fourth embodiment. The receiving device 1 in the fourth embodiment includes a soft decision signal level measurement unit 61 in addition to the configuration in the first embodiment. Only functional units different from the first embodiment will be described below. The soft decision signal level measurement unit 61 is also realized as a software component, a hardware component, or a combination thereof (see [Others]).

  The soft decision signal level measurement unit 61 measures the level of the received signal sequence (soft decision signal) before being output from the demodulation unit 12 and input to the turbo decoder 14. The soft decision signal level is not the result of judging whether the received signal sequence is 0 or 1 as in the hard decision, but indicates the probability that the received signal sequence is 0 or 1 by dividing each signal value into a plurality of levels. Value. The soft decision signal level measurement unit 61 acquires an average soft decision signal level for each UE in a predetermined period based on the measured soft decision signal level. The soft decision signal level measurement unit 61 sends the average soft decision signal level acquired in this way to the iteration number determination unit 17 together with the measurement time. The measurement time is the same as that measured by the throughput measuring unit 16.

The iteration number determination unit 17 receives throughput information from the throughput measurement unit 16 and receives an average soft decision signal level from the soft decision signal level measurement unit 61. The iteration number determination unit 17 obtains an index value by multiplying each measurement information by a weighting factor (see (Expression 1) below). This weighting factor is determined according to each measurement accuracy of the throughput measurement unit 16 and the soft decision signal level measurement unit 61, for example. In this case, when the measurement accuracy of the throughput measurement unit 16 is worse than that of the soft decision signal level measurement unit 61, the weight coefficient of the throughput information is decreased and the weight coefficient of the soft decision signal level is increased. That is,
The weighting coefficient is determined so that the importance in the index value of the measurement result of the functional unit with poor measurement accuracy decreases and the importance in the index value of the measurement result of the functional unit with good measurement accuracy increases. This weight coefficient is acquired by simulation or the like and is held in advance so as to be adjustable. Note that the larger the value of the throughput, the worse the reception quality, and the higher the average soft decision signal level, the better the reception quality. The weighting factors α and β are determined according to the characteristics of the measured values.

Index value = (throughput) × weighting coefficient α + (average soft decision signal level) × weighting coefficient β
... (Formula 1)
The iteration count determination unit 17 determines the accuracy of each measurement value based on the measurement time of each measurement value. If there is a measurement value with insufficient accuracy, the iteration number determination unit 17 replaces the measurement value with insufficient accuracy and holds it in advance. The predetermined value may be used, or another weighting factor held in advance in this case may be used. Further, the index value may be acquired using only the measurement value with sufficient accuracy. The iteration count determining unit 17 extracts the iteration count corresponding to the index value thus acquired from the iteration count determination table. The iteration count determination table in the fourth embodiment is also set so that the iteration count increases as the reception quality is poor, and the iteration count decreases as the reception quality is good.

[Operation example]
The operation of the receiving device 1 in the fourth embodiment will be described with reference to FIG. FIG. 7 is a flowchart illustrating an operation example of the receiving device 1 according to the fourth embodiment. In FIG. 7, the same processes as those in the first embodiment are denoted by the same reference numerals as those in FIG.

  The processes from S301 to S304 are the same as in the first embodiment. That is, the received signal sequence acquired by the demodulator 12 is sequentially output in the direction of the turbo decoder 14 in units of UE services (S301).

  The soft decision signal level measurement unit 61 measures the soft decision signal level of the received signal sequence (S701), and acquires the average soft decision signal level for each UE in a predetermined period based on the measurement result. The soft decision signal level measurement unit 61 sends the measurement time thereof together with the average soft decision signal level of this UE unit to the iteration number determination unit 17.

  At this time, the iteration count determination unit 17 requests the iteration count of the UE that is the transmission source of the decoding target service from the decoding control unit 18 as in the first embodiment. In response to this request, the iteration count determining unit 17 sends the throughput information of the target UE sent from the throughput measuring unit 16 and its measurement time, and the average soft decision signal of the target UE sent from the soft decision signal level measuring unit 61 Refer to level information and its measurement time.

  The iteration number determination unit 17 checks the accuracy of the throughput information and the average soft decision signal level information by comparing each measurement time with a threshold value stored in advance (S305). The iteration count determination unit 17 determines that the accuracy of each measurement information is sufficient when each measurement time is equal to or greater than the corresponding threshold (S305; YES), and uses the throughput information and the average soft decision signal level information. Each weight factor is multiplied. Thereby, the iteration number determination unit 17 acquires an index value based on each measurement value (S702). The iteration count determination unit 17 extracts the iteration count corresponding to the acquired index value from the iteration count determination table (S306).

When it is determined that the accuracy of either one of the measured values of the throughput and the average soft decision signal level is insufficient, the iteration number determination unit 17 uses only the measured value having sufficient accuracy as the index value. The number of iterations may be determined as follows, or an index value may be obtained by multiplying each measured value by a weighting factor according to accuracy, and the number of iterations may be determined using this index value. Good. On the other hand, if it is determined that the accuracy of both measured values is insufficient, the iteration count determining unit 17 determines the iteration count to an initial value that is held in advance (S307).

  Based on the number of iterations determined in this way, the turbo decoder 14 performs iterative decoding (S308). Since the subsequent processes (S308 to S312) are the same as those in the first embodiment, description thereof is omitted here.

<Operation and effect in the fourth embodiment>
As described above, in the receiving device 1 according to the fourth embodiment, as in the first embodiment, the throughput of each UE is determined based on the received data sequence decoded by the turbo decoder 14 and checked by the check unit 15. Are measured (throughput measuring unit 16). Furthermore, in the receiving device 1 in the fourth embodiment, the soft decision signal level of this received signal sequence is measured based on the received signal sequence obtained by the demodulator 12 (soft decision signal level measuring unit 61). That is, in the fourth embodiment, the throughput and the average soft decision signal level are measured for each UE.

  By multiplying each measured value by each weighting factor determined according to the measurement accuracy of each measurement function unit (throughput measurement unit 16 and soft decision signal level measurement unit 61), an index for the UE is obtained. The value is determined. By referring to the iteration number determination table, the number of iterations corresponding to the index value determined in this way is determined. Also in the fourth embodiment, the number of iterations is increased as the communication status is worse, and the number of iterations is decreased as the communication status is better. As a result, iterative decoding at the turbo decoder 14 is executed based on the number of iterations determined in this way.

  In the fourth embodiment, since soft decision signal level information is further used together with throughput information to determine the number of iterations, the actual communication status with the target UE can be determined more precisely, and the optimum The number of iterations can be determined. Furthermore, in determining the index value, since the weighting coefficient corresponding to the measurement accuracy of the measurement function unit that obtains each measurement information is multiplied, communication is performed in a state that includes all the performance and characteristics of the circuit included in the receiving device 1. The situation can be grasped.

  Therefore, according to the fourth embodiment, since the optimum number of iterations is used and turbo decoding is performed, the efficiency of saving wasteful decoding processing time while maintaining good reception quality according to each UE. Good decoding can be realized.

[Fifth embodiment]
Next, the receiving device 1 in the fifth embodiment will be described with reference to the drawings.

〔Device configuration〕
The device configuration of the receiving device 1 in the fifth embodiment will be described below using FIG. FIG. 8 is a block diagram illustrating a part of the functional configuration of the receiving device 1 according to the fifth embodiment. The receiving device 1 in the fifth embodiment further includes a soft decision signal level measuring unit 61 in addition to the configuration of the second embodiment. That is, the receiving device 1 in the fifth embodiment has a configuration in which the second embodiment and the fourth embodiment are combined.

In this case, as described in the fourth embodiment, the iteration number determination unit 17 receives the average soft decision signal level information sent from the soft decision signal level measurement unit 61 and the BLER information sent from the BLER measurement unit 41, respectively. The index value is acquired by multiplying the weighting factor. Since the weighting coefficient and other functions are the same as those in the fourth embodiment described above, description thereof is omitted here.

[Operation example]
The operation example of the receiving device 1 in the fifth embodiment is the same as that in the fourth embodiment except that the process S309 in the operation example of the fourth embodiment shown in FIG. 7 is replaced with the BLER measurement process.

<Operations and effects in the fifth embodiment>
As described above, since the receiving apparatus 1 according to the fifth embodiment adopts a configuration in which the second embodiment and the fourth embodiment are combined, the BLER and the average soft decision signal level are measured for each UE.

  Thereafter, as in the fourth embodiment, each measurement value is multiplied by each weighting factor determined according to the measurement accuracy of each measurement function unit (BLER measurement unit 41 and soft decision signal level measurement unit 61). By doing so, an index value for the UE is determined. As a result, iterative decoding at the turbo decoder 14 is executed based on the number of iterations corresponding to this index value.

  In the fifth embodiment, since soft decision signal level information is further used together with BLER information to determine the number of iterations, the actual communication status with the target UE can be determined more precisely and optimally. The number of iterations can be determined. Therefore, also in the fifth embodiment, the same effects as in the fourth embodiment can be obtained.

[Sixth embodiment]
Next, the receiving device 1 in the sixth embodiment will be described with reference to the drawings.

〔Device configuration〕
The device configuration of the receiving device 1 in the sixth embodiment will be described below using FIG. FIG. 9 is a block diagram illustrating a part of the functional configuration of the receiving device 1 according to the sixth embodiment. The receiving device 1 in the sixth embodiment further includes a soft decision signal level measurement unit 61 in addition to the configuration of the third embodiment. That is, the receiving device 1 in the sixth embodiment has a configuration in which the third embodiment and the fourth embodiment are combined.

  In this case, the iteration number determination unit 17, as described in the fourth embodiment, average soft decision signal level information sent from the soft decision signal level measurement unit 61 and average retransmission number sent from the retransmission number measurement unit 51. An index value is acquired by multiplying the information by a weighting factor. Since the weighting coefficient and other functions are the same as those in the fourth embodiment described above, description thereof is omitted here.

[Operation example]
The operation example of the receiving device 1 in the sixth embodiment is the same as that in the fourth embodiment except that the process S309 in the operation example of the fourth embodiment shown in FIG.

<Operation and effect in the sixth embodiment>
As described above, since the receiving apparatus 1 according to the sixth embodiment employs a configuration in which the third embodiment and the fourth embodiment are combined, the average number of retransmissions and the average soft decision signal level are measured for each UE. .

Thereafter, as in the fourth embodiment, each measurement function unit (retransmission count measurement unit 51) is added to each measurement value.
And the index value for the UE is determined by multiplying each weighting factor determined according to the measurement accuracy of the soft decision signal level measuring unit 61). As a result, iterative decoding at the turbo decoder 14 is executed based on the number of iterations corresponding to this index value.

  In the sixth embodiment, since soft decision signal level information is used to determine the number of iterations together with the average number of retransmissions information, the actual communication status with the target UE can be determined more precisely. The optimal number of iterations can be determined. Therefore, also in 6th embodiment, the effect similar to 4th embodiment can be acquired.

[First modification]
In the receiving apparatus 1 in the first to sixth embodiments described above, the number of iterations corresponding to the index value is determined by referring to the iteration number determination table as shown in FIG. The receiving device 1 in the first to sixth embodiments includes a plurality of iteration count determination tables corresponding to each service type, and an appropriate number of iterations based on the plurality of iteration count determination tables. May be determined. Hereinafter, the receiving apparatus 1 in the first modification applicable to the first to sixth embodiments will be described with reference to the drawings.

〔Device configuration〕
The device configuration of the receiving device 1 in the first modification is the same as that in the first to sixth embodiments described above. The difference from each of the above-described embodiments is that the iteration number determination unit 17 in the first modification has a plurality of iteration number determination tables according to service types, and the number of iterations is controlled in units of UE services. Is a point.

  In the first modification, the throughput measurement unit 16, the BLER measurement unit 41, the retransmission count measurement unit 51, and the soft decision signal level measurement unit 61 each measure each measurement value for each UE service. Accordingly, in the first modification, the iteration count determining unit 17 determines the iteration count in units of UE services, and the decoding control unit 18 sets the iterations to be set in the turbo decoder 14 in units of UE services. Control the number of times.

  The iteration number determination unit 17 in the first modified example further includes an iteration number determination table shown in FIG. 10 in addition to the iteration number determination table shown in FIG. Here, the iteration count determination table shown in FIG. 2 is used as a quality priority table with a weight on communication quality (hereinafter referred to as a quality priority table). The iteration count determination table shown in FIG. 10 is used as a processing time priority table with a weight on the processing time (hereinafter referred to as a processing time priority table). In the processing time priority table of FIG. 10, the maximum number of iterations is set smaller than that of the quality priority table of FIG. 2, and the index value range corresponding to the minimum number of iterations (one time) is set large (X13). This is the minimum number of iterations.)

  The iteration number determination unit 17 switches the iteration number determination table to be referred to according to the service type of the received signal sequence processed by the turbo decoder 14. Specifically, the iteration count determination unit 17 refers to the quality priority table and prioritizes processing time for data packets and the like in the case of a service that prioritizes communication quality that does not allow retransmission of audio, video, and the like. In the case of a service to be processed, the processing time priority table is referenced. In addition, although the example which uses two tables was shown in this 1st modification, you may make it use the some table according to a service type more finely.

The decoding control unit 18 monitors each received signal sequence input to the turbo decoder 14, determines the service type of the received signal sequence to be decoded, designates this service type, and specifies the service to be decoded this time. The number of iterations is requested to the iteration number determination unit 17.

<Operation and effect in the first modification>
As described above, the receiving apparatus 1 according to the first modification uses a plurality of tables that are set such that the relationship between the index value and the number of iterations changes according to the service type of the received signal sequence to be decoded. As a result, the number of iterations suitable for the service type is determined.

  Thereby, in the first modification, even when the same index value is obtained, the processing time is given priority in the case of a service in which communication quality is given priority according to the service type of the received signal sequence to be decoded. In some cases, the number of iterations is determined to be larger than that of the service to be performed.

  Therefore, according to the first modification, in addition to the actual communication status with the target UE such as the propagation environment and the circuit characteristics of the apparatus, it is possible to determine an appropriate number of iterations further considering QoS. it can. That is, iterative determination of the number of iterations can be realized more accurately than in the above embodiments. As a result, according to the first modification, it is possible to realize efficient decoding without using unnecessary decoding processing time while maintaining necessary reception quality according to the service executed with each UE. it can.

[Second modification]
In the receiving device 1 in the first to sixth embodiments described above, an appropriate number of iterations is assigned for each UE. According to such a configuration, when there are a plurality of UE services (received signal sequences) to which a large number of iterations are allocated within a TTI (Transmission Time Interval), the number of iterations allocated in this way is used. When the turbo decoding is performed, there is a case where the processing time limit assigned to the decoding process in the TTI unit is exceeded. Therefore, the receiving device 1 in each of the above-described embodiments may determine the number of iterations in consideration of this decoding processing time. This decoding process time limit is predetermined in the system. Hereinafter, the receiving apparatus 1 in the second modification applicable to the first to sixth embodiments will be described with reference to the drawings. In the following description, a case where the present invention is applied to the first embodiment as a representative example among the applicable first to sixth embodiments will be described as an example.

〔Device configuration〕
Hereinafter, the device configuration of the receiving device 1 in the second modification will be described with reference to FIG. FIG. 11 is a block diagram illustrating a part of the functional configuration of the receiving device 1 according to the second modification. The receiving apparatus 1 in the second modification shown in FIG. 11 includes a number correction unit 111 in addition to the configuration in the first embodiment. Only functional units different from the first embodiment will be described below. The number correction unit 111 is also realized as a software component, a hardware component, or a combination thereof (see [Others]).

  The decoding control unit 18 performs the following processing in addition to the processing in the first embodiment. That is, the decryption control unit 18 controls the number correction unit 111 so as to calculate the time required for the decryption processing of all services to be processed within the TTI. Specifically, when starting the decryption process for each service, the decryption control unit 18 instructs the number correction unit 111 to integrate the decryption process time for the service. At this time, the decryption control unit 18 also notifies the data amount of the decryption target service among the obtained decryption parameters. When the decoding process for all services in the TTI is completed, the decoding control unit 18 instructs the number correction unit 111 to clear the accumulated decoding processing time.

  Unlike the first embodiment, the decoding control unit 18 receives the number of iterations of the decoding target service from the number correction unit 111. The decoding control unit 18 sets the number of iterations sent from the number correction unit 111 in the turbo decoder 14.

  When the number correction unit 111 receives the integration instruction from the decoding control unit 18, the number correction unit 111 calculates the time required for the decoding process in the turbo decoder 14 of the service based on the data amount of the service notified at the same time. The result is added up to the decoding processing time that has been added up to that point. For example, the number correction unit 111 receives the data amount of the decoding target service from the decoding control unit 18 and divides this data amount by the decoding processable data amount per unit time of the turbo decoder 14 that is held in advance. Thus, the time required for one decryption process of the service is calculated. The number correction unit 111 calculates the decoding processing time of this service by multiplying the time calculated in this way by the number of iterations sent from the iteration number determination unit 17. In addition, since this embodiment does not limit the method for acquiring the decoding processing time necessary for each service, the time from when the service is actually input to the turbo decoder 14 until it is output is calculated. You may make it measure.

  The number correction unit 111 holds in advance the decoding process time limit assigned to the decoding process in units of TTIs. The number correction unit 111 performs control so that the accumulated decoding processing time does not exceed the decoding processing time limit. Specifically, when the number correction unit 111 determines that the accumulated decoding process time exceeds the decoding process time limit, the number of iterations is notified from the iteration number determination unit 17 as the number of iterations of the current decoding process target service. The number of iterations is corrected so that the accumulated time does not exceed the decoding processing time limit. On the other hand, when the number correction unit 111 determines that the accumulated decoding processing time does not exceed the decoding processing time limit, the number correction unit 111 sends the number of iterations notified from the iteration number determination unit 17 to the decoding control unit 18 as it is.

[Operation example]
Hereinafter, an operation example of the receiving apparatus 1 in the second modification will be described with reference to FIG. FIG. 12 is a flowchart illustrating an operation example of the reception device 1 in the second modification. In FIG. 12, the same processes as those in the first embodiment are denoted by the same reference numerals as those in FIG.

  First, process S301 is the same as that of the first embodiment. That is, the decoding control unit 18 monitors each received signal sequence input to the turbo decoder 14 as in the first embodiment, and all the services included in the TTI to be processed are service-unit-specific. Control is performed so as to be decoded. The decryption control unit 18 grasps the total number of services included in the TTI. The decryption control unit 18 initializes the variable of the number of services and the integration time when starting the decryption process of the processing target TTI. This accumulated time will be described later.

  The decoding control unit 18 counts up the number of decoding processing services (N) (S303), requests the iteration number determination unit 17 for the number of iterations of the UE that is the transmission source of the current decoding target service, The data amount of the decoding target service is sent to the correction unit 111 and the integration of the decoding processing time of the service is instructed.

  In response to this request, the iteration count determining unit 17 determines the iteration count of the target UE (S305, S306, S307), as in the first embodiment. The iteration number determination unit 17 sends the number of iterations determined in this way to the number correction unit 111.

In response to the instruction from the decoding control unit 18, the number correction unit 111 calculates the decoding processing time required for the turbo decoder 14 of the decoding target service. The number correction unit 111 adds the calculated decoding processing time to the decoding processing time accumulated so far (S1201).

  Next, the number correction unit 111 compares the accumulated time obtained by integrating the decryption processing times of the services to be decrypted with the previously held decryption process time limit (S1201). If the number correction unit 111 determines that the integration time does not exceed the decoding process time limit (S1201; NO), the number of iterations sent from the iteration number determination unit 17 is sent to the decoding control unit 18 as it is. On the other hand, if the number correction unit 111 determines that the integration time exceeds the decoding process time limit (S1201; YES), the number of iterations sent from the iteration number determination unit 17 is within the decoding time limit. Correction is made so as to fit (S1203). In this case, the number correction unit 111 sends the number of iterations corrected in this way to the decoding control unit 18.

  The decoding control unit 18 sets the number of iterations sent from the number correction unit 111 to the turbo decoder 14. Thereafter, as in the first embodiment, the turbo decoder 14 decodes the received signal sequence in units of services based on the decoding parameters set by the decoding control unit 18 (S308), and the throughput measuring unit 16 in units of UEs. Throughput is measured (S309).

  Such processing is executed for all services in the TTI.

  The decoding control unit 18 determines that the decoding process for all services in the TTI has been completed (S311; YES), and further determines that another received signal sequence exists (S312; YES), the decoding process for the next TTI is performed. (S301).

<Operation and effect in the second modification>
As described above, also in the receiving device 1 in the second modified example, the number of iterations is determined according to the index value obtained by the method in the first to sixth embodiments (iteration number determination unit 17). ).

  In the receiving apparatus 1 in the second modification, the time required for the decoding process to which the number of iterations determined in this way is applied is integrated in units of TTI, and the integrated time is allocated to the decoding process in units of TTI. Monitoring is performed so as not to exceed the processing time limit (number correction unit 111). If the integration time exceeds the decoding process time limit by this monitoring, the determined number of iterations is corrected so as to be within the decoding process time limit, and this corrected number of iterations is set in the turbo decoder 14. Is done.

  As a result, according to the second modification, if the service order decoded by the turbo decoder 14 is set to a service order that requires high communication quality, it is determined by the method in the first to sixth embodiments. The optimal number of iterations can be assigned in order from the service with the highest priority. Furthermore, since the number of iterations allocated to a service with a low priority is corrected so that the decoding process for all services is completed within the decoding process time limit determined by the system in units of TTI, the sixth embodiment to the sixth embodiment are corrected. The number of iterations determined by the method in the embodiment can be further supplemented so that the system operates normally.

  That is, according to the second modification, an appropriate number of iterations according to the actual communication situation including the propagation environment between the target UE and the receiving device 1 and the performance and characteristics of the circuit included in the receiving device 1 Is determined, and the number of iterations can be made appropriate for the entire system for a plurality of UEs. As a result, it is possible to realize efficient decoding without wasteful decoding processing time while maintaining good reception quality according to each UE, and it is possible to improve the throughput of the entire system.

[Third modification]
In the receiving device 1 in the second modification described above, turbo decoding based on the number of iterations determined by the method in each of the above-described embodiments is sequentially executed in the order of services in the TTI, and the integrated decoding processing time is decoding processing. When it was determined that the time limit was exceeded, the number of iterations determined for that service was corrected. According to such a configuration, the number of iterations for a service processed later in the TTI is a correction target. Therefore, the above-described second modified example is further modified to determine in advance whether or not the total decoding processing time required for decoding all services in the TTI exceeds the decoding processing time limit. Each iteration number for the service may be reduced by a predetermined amount. Hereinafter, a further modification of the above-described second modification will be described as a third modification with reference to the drawing, with regard to the receiving device 1 in the third modification. In the following description, a case where the present invention is applied to the first embodiment as a representative example among the applicable first to sixth embodiments will be described as an example.

〔Device configuration〕
The device configuration of the receiving device 1 in the third modification is the same as that in the second modification described above. The difference from the second modification described above is that the number correction unit 111 calculates the total decoding processing time required for the decoding process for all the services in the TTI before the decoding process for the TTI to be processed is started. It is determined in advance whether or not the total decoding processing time exceeds the decoding processing time limit, and the number of iterations for all services in the TTI is a correction target.

  In the third modified example, when starting the decoding process of the service within the TTI to be processed, the decoding control unit 18 sends the UE information and the data amount regarding all the services within the TTI to the number correcting unit 111, The corrected number of iterations is received from the number correction unit 111. The decoding control unit 18 sequentially sets the number of iterations of each service sent from the number correction unit 111 to the turbo decoder 14 when decoding each service. In addition, when the decoding control unit 18 starts the decoding process of the service within the TTI to be processed, the number of iterations determined for the number of iterations determined for each UE that is the transmission source of all the services within the TTI Instructs the iteration count determination unit 17 to send to 111.

  Based on the decoding parameter sent from the decoding control unit 18 and the number of iterations sent from the iteration number determination unit 17, the number correction unit 111 in the third modification example uses the same method as in the second modification example to Each time required for the decoding process is calculated. The number correction unit 111 calculates the total decoding processing time of all the services calculated in this way, and determines whether or not the total decoding processing time is within the decoding processing time limit determined by the system.

  When the number correction unit 111 determines that the total decoding processing time exceeds the decoding processing time limit, the iteration number determination unit 17 determines the decoding processing time of each service to be equal to or less than the weighted average time of the service. Reduce the number of iterations. The weighted average time of each service is shown in the following (Formula 2).

Alloc_t, i = alloc_all_t × proc_t, i / Σproc_t (Expression 2)
Here, Alloc_t, i represents the weighted average time of service i, alloc_all_t represents the decoding processing time limit in TTI units, proc_t, i represents the decoding processing time of service i before correction, and Σproc_t represents TTI before correction. The total decoding processing time for all the services is shown.

  The frequency correction unit 111 divides the weighted average time of the service i calculated by the above (Equation 2) by the time required for one decoding process of the service i calculated as in the second modification described above. The number of iterations is determined so as to be less than the weighted average time.

  When the number of iterations 111 determines the number of iterations for all services in the TTI to be processed, the number of times correction unit 111 sends them to the decoding control unit 18. If the number correction unit 111 determines that the total decoding processing time does not exceed the decoding processing time limit, the number of iterations of all services determined by the iteration number determination unit 17 is directly transmitted to the decoding control unit 18. send.

[Operation example]
Hereinafter, an operation example of the receiving device 1 in the third modification will be described with reference to FIGS. FIGS. 13 and 14 are flowcharts illustrating an operation example of the reception device 1 according to the third modification. 13 and 14 are denoted by the same reference numerals as those in FIG.

  First, the process S301 is the same as in the other embodiments, and the decoding control unit 18 monitors each received signal sequence input to the turbo decoder 14, and all services included in the TTI to be processed are service-based. The turbo decoder 14 is controlled to decode. The decoding control unit 18 grasps the total number of services included in the TTI, and initializes the variable (N) of the number of services and the total integration time when starting the decoding process of the processing target TTI (S1301). This total integration time will be described later.

  Before starting the decoding process of the TTI to be processed, the decoding control unit 18 sends the UE information and the data amount related to all the services in the TTI to the number correction unit 111, and the transmission sources of all the services in the TTI The iteration count determination unit 17 is instructed to send the iteration count determined for each UE to the count correction unit 111.

  The iteration count determination unit 17 receives a request from the decoding control unit 18 and performs processing using the same method as in each of the above-described embodiments based on each measurement value sent from each measurement unit so far. Determine the number of iterations for each UE for all services in the TTI of For example, when a service transmitted from two UEs is included in the TTI, the number of iterations for each of the two UEs is determined (S305, S306, and S307). The iteration number determination unit 17 sends the total number of iterations determined for the processing target TTI to the number correction unit 111.

  Based on the number of iterations sent from the iteration number determination unit 17, the number correction unit 111 calculates the time required for the decoding process for each service in the TTI by the same method as in the second modification described above. The number correction unit 111 adds up the decoding processing times of the services calculated in this way (S1201). In this way, the number correction unit 111 calculates the total decoding processing time required for the decoding processing of all the services included in the TTI in this way (S1303; YES). In the above description, the iteration number determination unit 17 and the number correction unit 111 have been described as collectively processing in units of TTI. However, in the flowchart of FIG. 13, the iteration number determination unit 17 and the number correction unit 111 are processed. Are shown to be processed in cooperation with each other.

When calculating the total decoding processing time (S1303; YES), the number correction unit 111 determines whether the total decoding processing time is within the decoding processing time limit in the TTI (S1305). When determining that the total decoding processing time exceeds the decoding processing time limit (S1305; YES), the number correction unit 111 corrects the number of iterations determined for each service by a weighted average (S1308). When the number of iterations 111 corrects the number of iterations related to all services in the TTI to be processed (S1309; YES), the number of corrections 111 sends the number of iterations related to all services to the decoding control unit 18. On the other hand, when the number correction unit 111 determines that the total decoding processing time is within the decoding processing time limit (S1305; NO), it sends the number of iterations determined for each service to the decoding control unit 18 as it is.

  When receiving the number of iterations from the number correction unit 111, the decoding control unit 18 starts decoding the TTI to be processed. At that time, when starting the decoding process for each service, the decoding control unit 18 sets the corrected number of iterations for the service in the turbo decoder 14. The turbo decoder 14 decodes the target service based on the corrected number of iterations and the like (S308). Thereafter, as in the other embodiments described above, the decoding control unit 18 causes the turbo decoder 14 to perform decoding processing for all services in the TTI, and the throughput measurement unit 16 determines the UE based on the decoded received data sequence. The unit throughput is measured (S309).

<Operation and effect in the third modification>
As described above, in the receiving device 1 in the third modified example, the number of iterations determined according to the index value obtained by the method in the first to sixth embodiments is decoded as in the second modified example. Correction is made in consideration of processing time.

  In the receiving apparatus 1 in the third modified example, before the decoding process of the TTI to be processed is started, the number of iterations determined for each service for each service is set for each service in the TTI. It is sent from the iteration number determination unit 17 to the number correction unit 111, respectively. Subsequently, based on the number of iterations, the total decoding processing time required for the decoding processing of all the services in the TTI is estimated (calculated). The number of iterations assigned to each service with the number of iterations for each UE determined in 17 is corrected for each service according to the mode (data amount, etc.) of each service. A weighted average for each service is used to correct the number of iterations.

  Thereby, according to the third modification, before the decoding process of the TTI to be processed is started, the number of iterations for all services in the TTI is about the measurement value and the TTI that reflect the actual communication situation. The predetermined decoding process time limit is taken into consideration.

  Therefore, it is possible to determine an appropriate number of iterations in any situation regardless of the UE connected to the receiving apparatus 1 and the mode of service to be performed, while maintaining good reception quality for each UE. Thus, it is possible to realize efficient decoding without wasteful decoding processing time.

[Modification of all embodiments]
In each of the above-described embodiments, assuming that there are a plurality of transmission apparatuses serving as communication partners, an example in which each measurement value such as throughput is measured in units of UE and the number of iterations is controlled is shown. Needless to say, the UE may be controlled without identifying the UE.

  Further, in each of the above-described embodiments, the iteration number determination unit 17 determines the number of iterations corresponding to each measurement value for each UE. However, this control unit may be used as a UE service unit. . In this case, the decoding control unit 18 notifies the completion of the decoding process for each service to the other function units, and the measurement function unit such as the throughput measurement unit 16 outputs the measurement value for each service of the UE. The number of iterations determination unit 17 may determine the number of iterations for each UE service.

Further, in the fourth embodiment, the fifth embodiment, and the sixth embodiment described above, the receiving apparatus 1 performs soft decision signal level measurement in addition to the throughput measurement unit 16, the BLER measurement unit 41, and the retransmission count measurement unit 51. Although the configuration further including the unit 61 is shown, only the soft decision signal level measurement unit 61 is provided, and the iteration number determination unit 17 determines the number of iterations based only on the average soft decision signal level. It may be. If comprised in this way, the signal can be decoded by the frequency | count of an iteration calculated | required from the information (average soft decision signal level) itself about the received signal series of object.

[Others]
<About hardware components (Component) and software components (Component)>
A hardware component is a hardware circuit, for example, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a gate array, a combination of logic gates, a signal processing circuit, an analog circuit, etc. There is.

  A software component is a component (fragment) that realizes the above function as software, and is not a concept that limits a language, a development environment, and the like that realize the software. Examples of software components include tasks, processes, threads, drivers, firmware, databases, tables, functions, procedures, subroutines, predetermined portions of program code, data structures, arrays, variables, parameters, and the like. These software components are implemented on one or a plurality of memories (one or a plurality of processors (for example, a CPU (Central Processing Unit), a DSP (Digital Signal Processor), etc.)).

  In addition, since each embodiment described above does not limit the method of realizing each functional unit, each functional unit may be a component of the hardware, a component of software, or a combination thereof. It may be configured by a method that can be realized by ordinary engineers.

<Appendix>
The following additional notes are further disclosed with respect to the embodiment including the above examples. The supplementary notes disclosed in each section can be combined as much as possible.

(Appendix 1)
Measuring means for measuring predetermined information from a signal after demapping processing of a multi-level modulation signal including a signal from a transmission device;
Determining means for determining the number of iterations corresponding to the predetermined information using the predetermined information measured by the measuring means as an index value;
Control means for controlling the decoder so that the signal from the transmission device is decoded at the number of iterations determined by the determination means;
A decoding control device comprising:

(Appendix 2)
The measurement unit uses the signal after the signal after the demapping processing is decoded by the decoder, and measures predetermined information according to a test result of the signal after the decoding by the tester. Decoding control device.

(Appendix 3)
The measurement means measures predetermined information according to the inspection result of the inspection device, and a soft decision signal level of the signal after the demapping process,
The determining means determines the number of iterations corresponding to an index value obtained by multiplying the predetermined information and the soft decision signal level by each weighting factor;
The decoding control device according to attachment 2.

(Appendix 4)
The determining means includes
The index value and the number of iterations are associated with each other, and a quality-oriented table in which the number of iterations corresponding to the same index value is set large and a speed-oriented table set in small are provided,
By determining a service type included in the signal after the demapping process and serving as a decoding unit of the decoder, and referring to one of the quality-oriented table and the speed-oriented table according to the service type, Determine the number of iterations corresponding to the index value,
4. The decoding control apparatus according to any one of appendices 1 to 3.

(Appendix 5)
Correction means for correcting the number of iterations when it is determined that the decoding processing time per unit time required for the decoding process using the number of iterations determined by the determining means exceeds the time limit per unit time;
Further comprising
The control means controls the decoder so that the signal from the transmission device is decoded with the number of iterations corrected by the correction means.
The decoding control apparatus according to any one of appendices 1 to 4.

(Appendix 6)
Before decoding a signal within the unit time, each service included in the signal within the unit time and serving as a decoding unit of the decoder is decoded using the number of iterations determined by the determining unit. Estimating means for estimating the total decoding processing time;
Further comprising
When the correction means determines that the total decoding processing time estimated by the estimation means exceeds the time limit, the number of iterations determined by the determination means for each service is corrected by a weighted average for each service. And
The control means decodes the signal within the unit time by the number of iterations of each service corrected by the correction means;
The decoding control apparatus according to appendix 5.

(Appendix 7)
The measuring means measures the predetermined information in units of signal transmission devices after the demapping processing,
The determining means determines the number of iterations in units of the transmitting device;
The decoding control apparatus according to any one of appendices 1 to 6.

(Appendix 8)
The measuring means measures a soft decision signal level as the predetermined information;
The decoding control apparatus according to attachment 1.

(Appendix 9)
The measurement means measures the throughput, BLER (Block Error Rate), or the number of retransmissions as the predetermined information.
The decoding control apparatus according to any one of appendices 1 to 7.

(Appendix 10)
A measurement step of measuring predetermined information from a signal after demapping processing of a multilevel modulation signal including a signal from a transmission device;
A determination step of determining the number of iterations corresponding to the predetermined information using the measured predetermined information as an index value;
A control step of controlling a decoder so that a signal from the transmission device is decoded at the determined number of iterations;
The decoding control method for executing

(Appendix 11)
The supplementary note 10 wherein the measurement step uses a signal after the signal after the demapping processing is decoded by the decoder, and measures predetermined information according to a test result of the signal after the decoding by the tester. Decoding control method.

(Appendix 12)
The measuring step measures predetermined information according to a test result of the tester and a soft decision signal level of the signal after the demapping process,
The determining step determines the number of iterations corresponding to an index value acquired by multiplying the predetermined information and the soft decision signal level by each weighting factor.
The decoding control method according to attachment 11.

(Appendix 13)
The determining step includes
A service type included in the signal after the demapping process and serving as a decoding unit of the decoder is determined, and the index value and the number of iterations are associated with each other according to the service type, and the same index value The number of iterations corresponding to the index value is determined by referring to one of the quality emphasis table in which the number of iterations corresponding to is set large and the speed emphasis table set small.
The decoding control method according to any one of appendices 10 to 12.

(Appendix 14)
A correction step for correcting the number of iterations when it is determined that the decoding processing time per unit time required for the decoding processing using the number of iterations determined in the determination step exceeds a time limit per unit time;
And execute
The control step controls the decoder so that the signal from the transmission device is decoded with the number of iterations corrected in the correction step.
14. The decoding control method according to any one of appendices 10 to 13.

(Appendix 15)
Before decoding a signal within the unit time, each service included in the signal within the unit time and serving as a decoding unit of the decoder is decoded using the number of iterations determined by the determining unit. An estimation step for estimating a total decoding processing time;
And execute
When the correcting step determines that the total decoding processing time estimated by the estimating means exceeds the time limit, the number of iterations determined by the determining means for each service is corrected by a weighted average for each service. And
The control step decodes the signal within the unit time based on the number of iterations of each service corrected by the correction unit.
The decoding control method according to attachment 14.

(Appendix 16)
The measuring step measures the predetermined information in a transmission device unit of the signal after the demapping process,
The determining step determines the number of iterations in units of the transmitting device.
The decoding control method according to any one of appendices 10 to 15.

(Appendix 17)
The measuring step measures a soft decision signal level as the predetermined information.
The decoding control method according to attachment 10.

(Appendix 18)
The measurement step measures the throughput, BLER (Block Error Rate), or the number of retransmissions as the predetermined information.
The decoding control method according to any one of supplementary notes 10 to 16.

It is a block diagram which shows a part of functional structure of the receiver in 1st embodiment. It is a figure which shows the example of an iteration count determination table. It is a flowchart which shows the operation example of the receiver in 1st embodiment. It is a block diagram which shows a part of functional structure of the receiver in 2nd embodiment. It is a block diagram which shows a part of functional structure of the receiver in 3rd embodiment. It is a block diagram which shows a part of functional structure of the receiver in 4th embodiment. It is a flowchart which shows the operation example of the receiver in 4th embodiment. It is a block diagram which shows a part of functional structure of the receiver in 5th embodiment. It is a block diagram which shows a part of functional structure of the receiver in 6th embodiment. It is a figure which shows the example of the iteration number determination table of processing time priority. It is a block diagram which shows a part of functional structure of the receiver in a 2nd modification. It is a flowchart which shows the operation example of the receiver in a 2nd modification. It is a flowchart which shows the operation example of the receiver in a 3rd modification. It is a flowchart which shows the operation example of the receiver in a 3rd modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Receiver 12 Demodulation part 14 Turbo decoder 15 Inspection part 16 Throughput measurement part 17 Iteration number determination part 18 Decoding control part 41 BLER measurement part 51 Retransmission number measurement part 61 Soft decision signal level measurement part 111 Number correction part

Claims (10)

Measuring means for measuring predetermined information from a signal after demapping processing of a multi-level modulation signal including a signal from a transmission device;
Determining means for determining the number of iterations corresponding to the predetermined information using the predetermined information measured by the measuring means as an index value;
Control means for controlling the decoder so that the signal from the transmission device is decoded at the number of iterations determined by the determination means;
A decoding control device comprising:   2. The measurement unit according to claim 1, wherein the measurement unit uses a signal after the signal after the demapping processing is decoded by the decoder, and measures predetermined information according to a check result by the checker of the signal after the decoding. The decoding control apparatus described. The measurement means measures predetermined information according to the inspection result of the inspection device, and a soft decision signal level of the signal after the demapping process,
The determining means determines the number of iterations corresponding to an index value obtained by multiplying the predetermined information and the soft decision signal level by each weighting factor;
The decoding control apparatus according to claim 2. The determining means includes
The index value and the number of iterations are associated with each other, and a quality-oriented table in which the number of iterations corresponding to the same index value is set large and a speed-oriented table set in small are provided,
By determining a service type included in the signal after the demapping process and serving as a decoding unit of the decoder, and referring to one of the quality-oriented table and the speed-oriented table according to the service type, Determine the number of iterations corresponding to the index value,
The decoding control apparatus according to any one of claims 1 to 3. Correction means for correcting the number of iterations when it is determined that the decoding processing time per unit time required for the decoding process using the number of iterations determined by the determining means exceeds the time limit per unit time;
Further comprising
The control means controls the decoder so that the signal from the transmission device is decoded with the number of iterations corrected by the correction means.
The decoding control apparatus according to any one of claims 1 to 4. Before decoding a signal within the unit time, each service included in the signal within the unit time and serving as a decoding unit of the decoder is decoded using the number of iterations determined by the determining unit. Estimating means for estimating the total decoding processing time;
Further comprising
When the correction means determines that the total decoding processing time estimated by the estimation means exceeds the time limit, the number of iterations determined by the determination means for each service is corrected by a weighted average for each service. And
The control means decodes the signal within the unit time by the number of iterations of each service corrected by the correction means;
The decoding control apparatus according to claim 5. The measuring means measures the predetermined information in units of signal transmission devices after the demapping processing,
The determining means determines the number of iterations in units of the transmitting device;
The decoding control apparatus according to any one of claims 1 to 6. The measuring means measures a soft decision signal level as the predetermined information;
The decoding control apparatus according to claim 1. The measurement means measures the throughput, BLER (Block Error Rate), or the number of retransmissions as the predetermined information.
The decoding control apparatus according to any one of claims 1 to 7. Measuring predetermined information from a signal after demapping processing of a multilevel modulation signal including a signal from a transmission device;
Determining the number of iterations corresponding to the predetermined information using the measured predetermined information as an index value;
Controlling a decoder so that a signal from the transmission device is decoded at the determined number of iterations;
The decoding control method for executing

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