JP2910990B2 - Transceiver for mobile communication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a code division multiple access (CDMA) mobile communication system, and more particularly, to frequency division full duplex (Frequenc).
y Division Duplex: FDD) and time division full duplex (Ti
The present invention relates to a transceiver for a mobile communication system, which realizes both TDD and me Division Duplex.

[0002]

2. Description of the Related Art In most public mobile communications, two-way communications are realized by FDD. In this case, different carrier frequencies are used for uplink and downlink in order to distinguish between an uplink channel (mobile station → base station) and a downlink channel (base station → mobile station). For example, in a PDC (Personal Digital Cellular) using the 800 MHz band, the carrier frequencies are separated by 130 MHz ("Digital car telephone system" standard, RCR STD-2).
7. See Radio System Development Center).

On the other hand, another two-way communication method is TD.
There is D. In this method, the same carrier frequency is used for uplink and downlink, and the separation of uplink and downlink channels is performed in the time domain. That is, the same frequency is alternately used for the up channel and the down channel. In this example, PHS (Personal Handyph
one system) (see "2nd generation cordless telephone system" standard, RCR STD-28, Radio System Development Center).

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a CD
An object of the present invention is to provide a transceiver for a mobile communication system that realizes both frequency division full duplex (FDD) and time division full duplex (TDD) in MA mobile communication with one unit.

[0005]

In order to achieve the above object, the present invention provides a CDMA (Code Division Multiple Acc
ess) In the transceiver for a mobile communication system, the transmission unit is interleaved with an interleaver for interleaving transmission data for each frame, and an interleave memory provided in the interleaver and capable of writing and reading in row and column units. Modulating means for data modulating transmission data to a narrow band modulated signal, and spreading modulating means for spreading and modulating the narrow band modulated signal to a wide band modulated signal using a spreading sequence, wherein the interleaver includes the interleaver. The interleaving is performed by writing the transmission data to the memory for each row and reading the transmission data for each column,
A receiving unit, a despreading unit that converts the wideband modulation signal into a narrowband modulation signal, a demodulation unit that demodulates the narrowband signal and outputs demodulated data, and deinterleaves the demodulated data for each frame. , A deinterleaver for reproducing the transmission data, provided in the deinterleaver,
A deinterleave memory that can be written and read in units of rows and columns, wherein the deinterleaver comprises:
The deinterleaving is performed by writing the demodulated data to the deinterleave memory for each column and reading the data for each row, and the transceiver reads data from the interleave memory and stores the data in the deinterleave memory. when writing, while controlling a constant speed V _T which is determined migration rate to the column (column / sec) previously from the column, the reading speed of the data in each column V _R and a write rate V _W (bits / sec ) Is variably controlled.

Further, the control means includes a reading speed V _R of each column data of the interleave memory and a writing speed V _W of each column data of the deinterleave memory.
(Bits / second) in the FDD mode, V _R = V
_W = V _T · M _s , where M _s is the number of bits in each column,
In the TDD mode, V _R > 2V _T · M _s and V
_{With W} > 2V _T · M _s , the transceiver can be switched from the transmission mode to the reception mode by the time when the reading of the next column is started after reading the last bit of the column.

[0007] In addition, the interleaver may write pilot symbols at the beginning of the interleaver memory.

Further, there may be provided transmission power control means connected to the output side of the spread modulation means for increasing the transmission power of important data in the transmission data.

[0009] The important data may be the pilot symbol and control data.

In the above configuration, the rows and columns may be exchanged.

According to the present invention, a CDMA system having a simple configuration
In mobile communications, frequency division full duplex (FDD) and time division full duplex (TDD) with only simple control of read and write speeds of interleaver and deinterleaver.
Can be realized by one device.

Also, if pilot symbols are written at the beginning of the interleaver memory, there is no need to insert pilot symbols later.

In addition, since the transmission power is increased for important data, important data is reliably received.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

First, the CDMA used in the present invention
A transmission method of the mobile communication system will be described.

FIG. 1A shows a frame configuration in normal mobile communication. The user data sequence to be transmitted is divided into frames of a predetermined time length. next,
Control data is added to the beginning of each frame,
A check code (for example, a CRC code) of user data for each frame is added to the last part of each frame to generate data for one frame. In FIG. 1A, there is a vacancy in the frame data when the total transmission rate including the control data, the user data, and the check code is lower than the maximum possible rate.

One frame data is interleaved as shown in FIG. 3 and is mapped to the radio channel frame shown in FIG. Known pilot symbols are periodically inserted into the frame. Using this pilot symbol, synchronous detection is performed on the receiving side. This method is described in, for example, Sanbei, "Fading Distortion Compensation Method of 16QAM for Land Mobile Communication", IEICE (B-II), vol. J-72-
B-II, pp. 7-15, January 1989. Or its English version, S. Sampei, "Fadin
g Compensation for 16QAM in Land Mobile Communicat
ions ", The Transactions of the Institute of Electr
onics, Information and CommunicationEngineers of J
apan B-II, Vol.J72-B-II pp. 7-15, January 1989, a
nd S. Sampei, et al. "Rayleigh Fading Compensation
for QAM in Land Mobile RadioCommunications ", IEEE
Transaction _s on Vehicular Technology, VOL. 42. N
o. See 2, MAY 1993.

In FIG. 1B, a section surrounded by pilot symbols is called a slot. One frame is N _s
If one slot is composed of M _s bits, one frame is composed of N _s * M _s bits.

The symbol sequence configured as described above is subjected to primary modulation, second-order modulation is performed with a spread code sequence having a chip rate that is an integral multiple (several tens to several hundreds) of the modulation symbol rate, and transmitted.

When a known pilot symbol is periodically inserted and transmitted, the receiving side estimates the state of the transmission path at each data position in the slot using the pilot symbol, and uses the pilot symbol for synchronous detection. It is used as a reference signal (see the above-mentioned S. Sampei article).

On the other hand, the transmission side has an interleaver for rearranging transmission data.

FIG. 2 is a conceptual diagram showing an interleave memory 3A used by the interleaver, and shows a configuration for one frame. Number of bits lines of the memory (number of columns) is the number N _s of slots constituting one frame, the number of bits of the column (number of lines) is equal to the maximum number of bits constituting one slot M _s. In this interleave memory, when writing one frame of transmission data, writing one bit at a time in the horizontal direction, and reading it out,
Read out vertically.

FIG. 3 shows a state where data is written in the interleave memory 3A. As shown in FIG. 3, data for one frame including a check code (CRC) for error detection and correction is written in the interleave memory 3A. The data is read from the interleaved memory 3A written in this manner in the vertical direction (for each column), and is sequentially mapped to the slots. Then, the column number (1 to N _s )
Correspond to the slot numbers in FIG. 1 (B).
As described above, when reading from the interleave memory, each slot becomes as shown in FIG. FIG. 1 (C)
1A and FIG. 3 corresponds to the presence of a space in one frame of data.

The above is the configuration for creating data on the transmission side. On the other hand, the receiving side also prepares a deinterleaver and reassembles the interleaved data sent back to the original arrangement. The deinterleaver also includes a deinterleave memory having the same configuration as that of FIG. 2, and the operation of the deinterleaver is the same as that of the interleaver in the direction of writing and reading. That is, the receiving side obtains the original data by writing in the column direction and reading in the horizontal row direction.

By transmitting in this way, it is possible to save power on the mobile station side. FIG. 4 shows this state. Pilot symbols, which are important data, and control data in the vicinity thereof are transmitted with high power. Then, the empty portion is not transmitted. This transmission method is
Japanese Patent Application No. 7-35702 filed by the present applicant earlier (PC
T / JP96 / 00419) "Transmission method and transmission device and reception device used therefor".

In such a transmission system, an embodiment of a transceiver for a mobile communication system according to the present invention in which both frequency division full duplex (FDD) and time division full duplex are realized by one unit will be described.

First, the frequency division full duplex (FDD) and the time division full duplex (TDD) will be described with reference to FIG. 5A and 5B are conceptual diagrams showing transmission states of FDD and TDD with respect to one frequency. FIG. 5A shows transmission data in the FDD mode, and FIG. 5B shows transmission data in the TDD mode. Is shown.

First, FIG. 5A shows a state where the transmitting section of the transceiver occupies the allocated frequency and transmits. The receiving unit of the transceiver receives data using another frequency.

On the other hand, FIG. 5B shows a state in which transmission and reception are switched with time using the same frequency. In this case, it is desirable to switch between transmission and reception for each slot since a pilot symbol is provided.

FIG. 6 shows such an FDD and a TDD,
1 shows a configuration of a transceiver realized by one wireless device. In FIG. 6, the framing unit 1 compiles transmission data for each frame. The error correction encoder 2 performs error correction coding on data collected for each frame. The interleaver 3 has the interleave memory 3A shown in FIG. 2, and assembles data of one frame into data of each slot. In reading from the interleave memory 3A, the transition speed V _T (column / second) from column to column is constant, but the read speed V _R (bit / second) for reading data (M _s bits / column) in each column. ) Can be switched depending on the mode of FDD and TDD. This will be described in more detail later.

The data modulator 4 performs primary modulation on data read from the interleave memory 3A. The spread modulator 5 performs second-order modulation of the output of the data modulator 4 from a narrow-band modulated signal to a wide-band signal, and outputs a spread signal. Frequency converter 6 converts this spread signal to a carrier frequency and outputs a transmission signal. This carrier is supplied from the carrier frequency generator 9 to the frequency converter 6. The transmission signal thus created is wirelessly transmitted in the air via the transmission / reception splitter 7 and the antenna 15.

When it is necessary to control the transmission power as shown in FIG. 4, the frequency converter 6 and the transmission / reception splitter 7
The transmission power control circuit 17 is inserted between the two to control the transmission power. In this case, each data length of the pilot symbol, control data, and semi-important user data shown in FIG. 4 is predetermined, and transmission power is controlled according to each data length.

Next, the configuration of the receiving section will be described. The received signal received via the antenna 15 and the transmission / reception splitter 7 is supplied to the frequency converter 14. This received signal is
In the frequency converter 14, the frequency is converted by a signal from the carrier frequency generator 9. The frequency-converted signal is converted from a spread wideband signal to a narrowband modulation signal by a despread demodulator 13 and then converted to a data demodulator 12.
Is returned to the original data signal.

The bit deinterleaver 11 restores the original data frame using the deinterleave memory 11A. Write to this deinterleave memory 11A, the migration rate V _T from column to column is constant, the writing speed V _W of each column in the data (bits / sec) is switched by the mode FDD and TDD Will be executed.
The error correction decoder 10 corrects the error of each frame output from the deinterleaver 11 for each frame, and outputs it as received data.

The transmitting section and the receiving section are controlled by the main control section 20 and the sub-control section 21.

FIG. 7 is a block diagram showing the configuration of the sub control unit 21. In the figure, a read clock generator 22
Are the memory 3A of the interleaver 3 and the deinterleaver 11
Of the memory 11A. on the other hand,
The write clock generator 23 includes the memories 3A and 11A
Generates a write clock. Frequency of these clocks, in TDD mode, write rate V _W of the read rate V _R and the memory 11A of the memory 3A becomes both greater than twice the normal speed _{V N = M s * V T} ( bits / sec) As described above, the clock control unit 24 is controlled. Here, M _s is the memory 3A and 11A the number of data bits of one column (bit / column), the V _T transition rate from row to row: a (column / sec constant). The reason why the read speed V _R of the memory 3A and the write speed V _W of the memory 11A are set to be larger than twice the normal speed is to generate an idle time in the output of the interleaver 3. For example, when V _R = 2.5V _N , an empty time for 0.6 slot occurs in one slot. During this idle time, transmission and reception can be switched.

Further description will be given. Clock control unit 24 of the sub-controller 21, in FDD mode, such that the write rate V _W of the read rate V _R and the memory 11A of the memory 3A is generates a clock of a frequency that both of the normal rate V _N Next, the clock generators 22 and 23 are controlled. On the other hand, in a TDD mode, the reading period of the memory 3A, the read rate V _R is more than twice the normal speed, for example, 2.5V _N, and the memory 11A
During the writing period, the writing speed _VW is 2 times the normal speed.
The clock generators 22 and 23 are controlled so as to generate a clock having a frequency larger than twice, for example, 2.5 V _N. Note that the writing speed to the memory 3A and the reading from the memory 11A are determined by FDD and TDD.
It carried out at normal speed V _N in any of the modes DD.

The carrier frequency control unit 25 includes a main control unit 2
According to the instruction of 0, the frequency of the carrier generated by the carrier frequency generator 9 is controlled. That is, in the FDD mode, the carrier frequency generator 9 is controlled so that the transmission carrier frequency f _T and the transmission carrier frequency f _R have predetermined different frequencies, while in the TDD mode, the transmission carrier frequency f _T And the carrier frequency generator 9 is controlled so that the carrier frequency f _R and the received carrier frequency f _R are the same.

In such a configuration, FDD and TDD
The operation of this embodiment for realizing the above with one transceiver will be described.

The data sequence to be transmitted depends on the framing unit 1
Supplied to The framing unit 1 divides the transmission data sequence into data for each predetermined frame time (T _f ) to form a frame. The error correction encoder 2
For each frame, transmission data in the frame is error-correction-coded and supplied to the interleaver 3. Interleaver 3, the transmission data at normal speed V _N, the interleave memory 3A of the M _s line × N _s columns, writes for each row (lateral direction). At this time, if a pilot symbol is written in the first row, there is no need to add the pilot symbol later. After writing the transmission data for one frame, the interleaver 3 reads the written transmission data for each column (vertical direction). Hereinafter, the FDD mode and the TDD
The operation will be described separately for each mode.

(1) Operation in FDD Mode In the FDD mode, the interleaver 3 of the transmission unit uses the clock signal supplied from the read clock generator 22 to output the normal speed V _N (= M _s · V _T ) bits / sec. Then, the transmission data in the interleave memory 3A is read for each column. That is, in the case of FDD mode, the read speed of the memory 3A is V _R = V _N. Each column of the memory 3A is 1
Since a slot is configured, one slot is configured with M _s bits (including a pilot symbol).

The transmission data sequence created by the interleaver 3 is data-modulated by the data modulator 4 and
Is spread modulated. Then, after being converted to the transmission frequency f _T which is specified by the frequency modulator 6, and transmitted. This transceiver includes a transmission / reception splitter 7, which separates transmission and reception frequency components.

On the other hand, the frequency converter 14 of the receiver converts the frequency of the received wave at the designated frequency f _R. The frequency-converted received signal is despread and demodulated by a despread demodulator 13 and data demodulated by a data demodulator 12. The demodulated data is supplied to a deinterleaver 11. The deinterleaver 11 writes the demodulated data into the deinterleave memory 11A for each column (vertical direction) at a write speed V _W = V _N (normal speed) in accordance with the clock signal supplied from the write clock generator 23. . Written data at a normal speed V _N, are read out for each row (lateral direction).

That is, in the FDD mode, the read speed of the interleave memory 3A and the write speed of the deinterleave memory 11A are both equal to the normal speed V.
_Although it is _N , the writing direction and reading direction of the deinterleave memory 11A are opposite to those of the interleave memory 3A. Deinterleave memory 1
The portion of the pilot symbol in 1A is empty. These two points are deinterleaver 11 and interleaver 3
Is a different point. The data output from the deinterleaver 11 is subjected to error correction decoding by the error correction decoder 10 to obtain the original data.

(2) Operation in TDD Mode In the TDD mode, the carrier frequency control unit 25 of the sub control circuit 21 sets the transmission frequency f _T and the reception frequency f _R to be the same (f _T = f _R ). Simultaneously, the reading speed V _R of the interleave memory 3A and V _R> 2V _N, write speed of the deinterleave memory 11A V _W
Is V _W > 2V _N. For example, V _{R of the} interleave memory 3A = V _{W of the} deinterleave memory 11A =
And 2.5V _N, creating a 0.6 free time slots in one slot. During this idle time, transmission and reception can be switched. Other operations are the same as those in the case of the FDD mode.

In the spread modulation, the signal after data modulation is
The modulation is performed with a spreading sequence having a higher rate than the bit rate of the transmission data. The spreading sequence speed (chip rate) in the TDD mode may be the same as that in the FDD mode, or may be the same as the reading speed in the FDD mode. The same magnification speed may be used.

[0047]

As described above, according to the present invention,
With a simple configuration, in a CDMA mobile communication system, both frequency division full duplex (FDD) and time division full duplex (TDD) can be realized by a single unit by simply controlling the read and write speeds of the interleaver and deinterleaver. it can.

Also, if pilot symbols are written at the beginning of the interleaver memory, there is no need to insert pilot symbols later.

In addition, since the transmission power is increased for important data, important data is reliably received.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram illustrating a transmission method used in an embodiment of a transceiver for a mobile communication system according to the present invention;
(A) shows the configuration of the transmission data frame, and (B)
Indicates the configuration of a radio channel frame obtained by periodically inserting pilot symbols with a known pattern,
(C) shows the configuration of a wireless channel slot.

FIG. 2 is a conceptual diagram showing a configuration of an interleave memory 3A of the embodiment.

FIG. 3 is a conceptual diagram showing a state where data is stored in the memory 3A.

FIG. 4 is a conceptual diagram showing an example of transmission power control in the embodiment.

FIG. 5 is a conceptual diagram illustrating FDD and TDD;
(A) shows the FDD mode, and (B) shows the TDD mode.

FIG. 6 is a block diagram showing an embodiment of a transceiver for a mobile communication system according to the present invention.

FIG. 7 is a block diagram illustrating a configuration of a sub control circuit according to the first embodiment.

[Explanation of symbols]

 Reference Signs List 1 framing unit 2 error correction encoder 3 interleaver 3A interleave memory 4 data modulator 5 spreading modulator 6 frequency converter 7 transmission / reception demultiplexer 10 error correction decoder 11 bit deinterleaver 11A deinterleave memory 12 data demodulation Device 13 despread demodulator 14 frequency converter 15 antenna 20 main control unit 21 sub-control unit 22 read clock generator 23 write clock generator 24 clock control unit 25 carrier frequency control unit

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04B 1/707 H04B 1/40 H04Q 7/38

Claims (10)

(57) [Claims] 1. A CDMA (Code Division Multiple Acc)
ess) In the transceiver for a mobile communication system, the transmission unit includes: an interleaver for interleaving transmission data for each frame; an interleave memory provided in the interleaver and capable of writing and reading in row and column units; Modulating means for data modulating transmission data to a narrow band modulated signal, and spreading modulating means for spreading and modulating the narrow band modulated signal to a wide band modulated signal using a spreading sequence, wherein the interleaver comprises the interleaver The interleaving is performed by writing the transmission data to the memory for each row and reading for each column, and a receiving unit includes: a despreading unit that converts the wideband modulation signal into a narrowband modulation signal; and the narrowband signal. Demodulating means for demodulating the demodulated data and outputting demodulated data; A deinterleaver that releaves and reproduces the transmission data; and a deinterleave memory that is provided in the deinterleaver and that can be written and read in row and column units. Performing the deinterleaving by writing the demodulated data to a column and reading the data row by row, wherein the transceiver reads data from the interleave memory and writes data to the deinterleave memory; The transition speed from column to column (column / second) is controlled to a predetermined constant speed V _T , while the reading speed V _R and writing speed V _W (bit / second) of data in each column are variably controlled. A transceiver for a mobile communication system, comprising a control unit. 2. The transceiver for a mobile communication system according to claim 1, wherein said control means includes said interleaver.
Reading speed of each column data in the memory V _R and a write rate for each column data of said deinterleave memory V
_W (bits / second) is V _R = V _W = V _T · M _s in the FDD mode, where M _s is the number of bits in each column, and in TDD mode, V _R > 2V _T · M _s And V
_W > 2V _T · M _s, and after the last bit of a column is read, the transceiver is switched from a transmission mode to a reception mode by a reading start time of a next column. Machine. 3. The transceiver for a mobile communication system according to claim 1, wherein said interleaver writes a pilot symbol at the beginning of said interleaver memory. 4. The transmitter / receiver for a mobile communication system according to claim 1, further connected to an output side of said spread modulation means to increase transmission power of important data in said transmission data. A transceiver for a mobile communication system, comprising transmission power control means. 5. The transceiver according to claim 4, wherein the important data is the pilot data.
A transceiver for a mobile communication system, which is a symbol and control data. 6. A CDMA (Code Division Multiple Acc)
ess) In the transceiver for a mobile communication system, the transmission unit includes: an interleaver for interleaving transmission data for each frame; an interleave memory provided in the interleaver and capable of writing and reading in units of columns and rows; Modulating means for data modulating transmission data to a narrow band modulated signal, and spreading modulating means for spreading and modulating the narrow band modulated signal to a wide band modulated signal using a spreading sequence, wherein the interleaver comprises the interleaver The interleaving is performed by writing the transmission data to a memory for each column and reading the data for each row, and a receiving unit includes: a despreading unit that converts the wideband modulation signal into a narrowband modulation signal; and the narrowband signal. Demodulating means for demodulating the demodulated data and outputting demodulated data; A deinterleaver for reproducing the transmission data by releaving; and a deinterleave memory provided in the deinterleaver and capable of writing and reading in units of columns and rows, wherein the deinterleaver includes the deinterleaver. The deinterleaving is performed by writing the demodulated data to a memory for each row and reading the data for each column.The transceiver reads data from the interleave memory and writes data to the deinterleave memory. while controlling to a constant speed V _T which is predetermined transition velocity to rows (rows / sec) from the row, the data reading speed in each row V _R and a write rate V _W (bit / sec) is variably controlled A transceiver for a mobile communication system, comprising a control unit. 7. The transceiver for a mobile communication system according to claim 1, wherein:
Read rate V _R and the deinterleave memory row data write speed V of each row data in the memory
_W (bits / second) is V _R = V _W = V _T · M _s in the FDD mode, where M _s is the number of bits in each row. In the TDD mode, V _R > 2V _T · M _s and V
_W > 2V _T · M _s, and after the last bit of a row is read, the transceiver is switched from a transmission mode to a reception mode by a reading start time of the next row, and transmission / reception for a mobile communication system is characterized in that Machine. 8. The transceiver for a mobile communication system according to claim 6, wherein the interleaver writes a pilot symbol at the beginning of the interleaver memory. 9. The transceiver for a mobile communication system according to claim 6, further connected to an output side of said spread modulation means to increase transmission power of important data in said transmission data. A transceiver for a mobile communication system, comprising transmission power control means. 10. The transceiver for a mobile communication system according to claim 9, wherein the important data is the pilot symbol and control data.