JP4069154B2 - Mobile station, base station, communication system and communication method - Google Patents

Description

The present invention relates to a mobile station, a base station, a communication system, a transmission method, a reception method, a communication method, an IQ multiplexing apparatus, and an IQ multiplexing method that perform high-speed data communication.

As mobile radio communication systems represented by mobile phones, a plurality of communication systems called third generations are adopted as IMT-2000 in the ITU (International Telecommunication Union), and among them, W-CDMA (Wideband Code Division Multiple Access) system In 2001, commercial service was started in Japan.
The purpose of the W-CDMA system is to obtain a communication speed of about 2 Mbps (bit per second) at the maximum per mobile station, and the version of the standard compiled in 1999 in 3GPP (3rd Generation Partnership Project), which is a standardization organization. The first specification has been determined as Release 99 (Release 1999) version.

FIG. 21 is a general conceptual diagram showing a conventional communication system. In FIG. 21, 1 is a base station, 2 is a mobile station that performs wireless communication with the base station 1, and 3 is a data that is transmitted from the base station 1 to the mobile station 2. 4 is an uplink used when the mobile station 2 transmits data to the base station 1.

FIG. 22 is a configuration diagram showing the internal configuration of the mobile station 2. In FIG. 22, reference numeral 11 indicates that data DPDCH of a dedicated data channel (Dedicated Physical Data Channel) is distributed in parallel, and data DPDCH1 to DPDCH6 of a plurality of data channels is distributed. 12 is a spread that performs spread spectrum by multiplying the data DPDCH1 to DPDCH6 output from the distributor 11 and the control data DPCCH of the control channel (Dedicated Physical Control Channel) by a spreading code for channel separation. 13 is a scrambler that generates a complex signal (I signal: Inphase signal, Q signal: Quadrature signal) by IQ multiplexing the output signal of the spreader 12, and 14 is generated by the scrambler 13. A modulation unit that orthogonally modulates the complex signals (I signal and Q signal) generated to generate a modulation signal, 15 a frequency conversion unit that frequency-converts the modulation signal generated by the modulation unit 14 and outputs a radio frequency signal; Reference numeral 16 denotes an antenna that transmits the radio frequency signal output from the frequency converter 15.

FIG. 23 is a block diagram showing the internal configuration of the spreader 12 and the scrambler 13. In FIG. 23, reference numerals 21 to 26 denote channel separation spreading codes Cd, 1 for the data DPDCH1 to DPDCH6 output from the distributor 11. Multiplier for multiplying ~ Cd, 6, 27 is a multiplier for multiplying control data DPCCH of the control channel by a spreading code Cc for channel separation, 31-36 are for the output signals of the multipliers 21-26 A multiplier 37 multiplies the DPDCH amplitude coefficient βd. A multiplier 37 multiplies the output signal of the multiplier 27 by the DPCCH amplitude coefficient βc.
38 is an adder that adds the output signals of the multipliers 31 to 33, 39 is an adder that adds the output signals of the multipliers 34 to 37, and 40 is a multiplier that multiplies the output signal of the adder 39 by an imaginary number j. , 41 is an adder that adds the output signal of the adder 38 and the output signal of the multiplier 40, and 42 is a complex signal (multiplying the output signal of the adder 41 by a mobile station identification identification code Sdpch, n. It is a multiplier that outputs (I signal, Q signal).

Next, the operation will be described.
An operation when the mobile station 2 transmits data to the base station 1 will be described. When the mobile station 2 transmits data to the base station 1, as shown in FIG. 21, data is transmitted using the uplink 4. In the W-CDMA standard, one mobile station 2 is connected to the uplink 4. When using, data of up to six data channels can be transmitted according to the communication speed required for the communication service.
Here, for convenience of explanation, a case will be described in which data of six data channels and control data of one control channel are transmitted.

First, the distributor 11 of the mobile station 2 distributes the data DPDCH of the dedicated data channel in parallel and outputs the data DPDCH1 to DPDCH6 of the plurality of data channels.
When the distributor 11 outputs the data DPDCH1 to DPDCH6 of a plurality of data channels, the multipliers 21 to 26 of the spreader 12 output spread codes Cd, 1 to Cd, 6 for channel separation with respect to the data DPDCH1 to DPDCH6. And the multiplier 27 of the spreader 12 multiplies the control data DPCCH of the control channel by the spread code Cc for channel separation.

The scrambler 13 IQ multiplexes the output signal of the spreader 12 to generate a complex signal (I signal, Q signal).
That is, the multipliers 31 to 36 of the scramble unit 13 multiply the output signals of the multipliers 21 to 26 in the spreader 12 by the amplitude coefficient βd for DPDCH, and the multiplier 37 of the scramble unit 13 The output signal of the multiplier 27 is multiplied by the amplitude coefficient βc for DPCCH.
Here, FIG. 24 is a table showing the possible values of the amplitude coefficients βd and βc. The amplitude coefficients βd and βc are coefficients for determining the power ratio between the data DPDCH1 to DPDCH6 and the control data DPCCH, and are defined in 3GPP standard TS25.213v3.6.0 (2001-06) (Release 1999). The right side of the table shows the values that the amplitude coefficients βd and βc can take.

Then, the adder 38 of the scramble unit 13 adds the output signals of the multipliers 31 to 33, and the adder 39 of the scramble unit 13 adds the output signals of the multipliers 34 to 37.
The multiplier 40 of the scrambler 13 multiplies the output signal of the adder 39 by an imaginary number j in order to assign the output signal of the adder 39 to the Q axis.
Here, the data DPDCH1, DPDCH3, and DPDCH5 are assigned to the I axis, and the data DPDCH2, DPDCH4, and DPDCH6 are assigned to the Q axis, but the data channel assignment method for the I / Q axis is TS25.213 of the 3GPP standard. It is stipulated in.

Next, the adder 41 of the scrambler 13 adds the output signal of the adder 38 and the output signal of the multiplier 40, and the multiplier 42 of the scrambler 13 identifies the mobile station with respect to the output signal of the adder 41. Multiplicative identification codes Sdpch, n are multiplied to output complex signals (I signal, Q signal).
When the scrambler 13 generates a complex signal (I signal, Q signal) as described above, the modulation unit 14 orthogonally modulates the complex signal (I signal, Q signal) to generate a modulated signal.
When the modulation unit 14 generates a modulation signal, the frequency conversion unit 15 converts the frequency of the modulation signal to generate a radio frequency signal, amplifies the radio frequency signal, and outputs the amplified signal to the antenna 16. As a result, a radio frequency signal is transmitted from the antenna 16 to the base station 1.

When the base station 1 receives the radio frequency signal transmitted from the mobile station 2, the base station 1 acquires data by performing the reverse operation of the mobile station 2.
In the above conventional example, six data channels are set. However, when the number of data channels is five or less, the data DPDCH1 is assigned to the I / Q axis in order, and unnecessary data is used. No processing is performed on the channel. The number of data channels set is determined by the required communication service and communication speed.

Here, FIG. 25 is an explanatory diagram showing a complex plane when the number of data channels set is one.
In this case, data DPDCH1 of the data channel is assigned to the I axis, and control data DPCCH of the control channel is assigned to the Q axis.
Thereby, since data DPDCH1 and control data DPCCH are orthogonal to each other, base station 1 can separate and demodulate both channels.
The same applies to the case where the number of data channels set is 2-6. However, when the set number of data channels is 2 to 6, channel components on the same axis can be separated by using a spreading code for channel separation.

In the above conventional example, one downlink 3 and one uplink 4 are set between the base station 1 and the mobile station 2, but downlink data transmitted from the base station 1 to the mobile station 2 is shown. As shown in FIG. 26, HSDPA (High Speed Downlink Packet Access) in which a downlink 5 is newly added in addition to the conventional downlink 3 has been proposed and studied (TR25. 858v1.0.0 (2001-12) "High Speed Downlink PacketAccess: Physical Layer Aspects (Release 5)").

In addition, when newly adding the downlink 5, it is considered that the mobile station 2 transmits response data (ACK / NACK) or the like for the downlink high-speed packet data to the base station 1, as shown in FIG. In addition, a dedicated control channel (uplink channel 6) for transmitting the response data is separated and identified by a spreading code for channel separation in the same manner as the conventional control channel, and then the conventional uplink 4 In the direction of additional multiplexing. In TR25.858, a dedicated control channel is described as “additional DPCCH”.
Japanese Patent Laid-Open No. 10-341188 JP 2001-267959 A

Since the conventional communication system is configured as described above, it is necessary to allocate a newly added dedicated control channel to the I axis or Q axis, but to allocate the dedicated control channel to the I axis or Q axis. If the peak power of the I-axis or Q-axis increases as a result, for example, in a quadrature modulator (or quadrature modulation amplifier) built in the modulation unit 14 of the mobile station 2, a non-linear region of its input / output characteristics is used. Therefore, distortion occurs. Further, when the balance between the signal power of the I axis and the signal power of the Q axis is lost, the peak power of the modulated signal after orthogonal modulation output from the modulation unit 14 is balanced between the I axis and the Q axis. For example, when a radio frequency signal is amplified using an amplifier built in the frequency conversion unit 15 of the mobile station 2, a non-linear region of the input / output characteristics of the amplifier is used, so that distortion is caused. appear. As described above, when distortion occurs in the amplifier and a nonlinear component is output, the nonlinear component interferes with a signal component in the adjacent frequency band, thereby disturbing the adjacent frequency band.

The present invention has been made in order to solve the above-described problems. A mobile station, a base station, a communication system, and a transmission capable of suppressing the occurrence of distortion in an amplifier and suppressing interference with an adjacent frequency band. It is an object to obtain a method, a receiving method, a communication method, an IQ multiplexing apparatus, and an IQ multiplexing method.

The mobile station according to the present invention modulates a complex signal generated by IQ multiplexing means for generating a complex signal by IQ multiplexing the transmission data of the data channel and the control data of the control channel, and modulating the complex signal generated by the IQ multiplexing means. The IQ multiplexing unit alternately assigns the transmission data of the data channel to the I axis and the Q axis, and when the control data of the control channel is added, the set number of data channels is If the number is odd, the control data is assigned to the Q axis, and if the number of data channel settings is an even number, the control data is assigned to the I axis.

According to the present invention, there is an effect that it is possible to suppress the occurrence of distortion of the amplifier and to suppress the interference to the adjacent frequency band.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a mobile station applied to a communication system according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 51 denotes a plurality of data channels by distributing data DPDCH of dedicated data channels in parallel. A distributor 52 outputs data DPDCH1 to DPDCH6, and 52 multiplies data DPDCH1 to DPDCH6 output from distributor 51 and control data DPCCH and ADPCCH (ADPCCH: additional DPCCH) for channel separation by a spreading code for channel separation. The spreader performs spread spectrum, 53 distributes the control data ADPCCH of the control channel after spread by the spreader 52, and 54 multiplexes the output signals of the spreaders 52 and 53 by IQ multiplexing. Scrambler for generating signals (I signal, Q signal) A.
The distributor 51, the spreader 52, the distributor 53, and the scrambler 54 constitute IQ multiplexing means.

55 is a modulation unit that generates a modulated signal by orthogonally modulating the complex signal (I signal, Q signal) generated by the scramble unit 54, and 56 is a radio frequency signal by frequency-converting the modulation signal generated by the modulation unit 55. Reference numeral 57 denotes an antenna for transmitting a radio frequency signal output from the frequency converter 56.
The modulation unit 55, the frequency conversion unit 56, and the antenna 57 constitute transmission means.

2 is a block diagram showing a base station applied to the communication system according to Embodiment 1 of the present invention. In the figure, 61 is an antenna for receiving a radio frequency signal transmitted from the mobile station 2, and 62 is an antenna 61. The frequency conversion unit 63 converts the radio frequency signal received by frequency and outputs a baseband signal, and 63 orthogonally demodulates the baseband signal output from the frequency conversion unit 62 to generate a complex signal (I signal, Q signal). It is an orthogonal demodulator for output.
The antenna 61, the frequency conversion unit 62, and the quadrature demodulation unit 63 constitute reception means.

64 is a descrambling unit that multiplies a complex signal (I signal, Q signal) output from the quadrature demodulation unit 63 by an identification code for identifying a mobile station, and 65 is a channel separation for the output signal of the descrambling unit 64. A despreader that multiplies the data for each channel by separating the data for each channel, 66 combines the data DPDCH1 to DPDCH6 for the data channel, and reproduces the data DPDCH for the dedicated data channel; A synthesizer 67 synthesizes control data ADPCCH of control channels allocated to the I axis and the Q axis.
The descrambler 64, the despreader 65, the data channel merger 66, and the combiner 67 constitute IQ separating means.

FIG. 3 is a block diagram showing the internal configuration of the spreader 52, distributor 53, and scrambler 54. In the figure, reference numerals 71 to 76 denote channel separation spreads for the data DPDCH1 to DPDCH6 output from the distributor 51. A multiplier that multiplies the codes Cd, 1 to Cd, 6, 77 is a multiplier that multiplies the control data DPCCH for the control channel by a spreading code Cc for channel separation, and 78 is a control for the control channel to be newly added. Multipliers that multiply the data ADPCCH by a spreading code Ccc for channel separation, 81-86 are multipliers that multiply the output signals of the multipliers 71-76 by the amplitude coefficient βd for DPDCH, and 87 is a multiplier 77. Multipliers 88 and 89 multiply the output signal of DPCCH by the amplitude coefficient βc for DPCCH. This is a multiplier for multiplying the number βcc.

90 is an adder that adds the output signals of the multipliers 81 to 83, 88, 91 is an adder that adds the output signals of the multipliers 84 to 87, 89, and 92 is an imaginary number j for the output signal of the adder 91. A multiplier 93 for multiplying, an adder for adding the output signal of the adder 90 and an output signal of the multiplier 92, and 94 multiplying the output signal of the adder 93 by an identification code Sdpch, n for identifying a mobile station. The multiplier outputs a complex signal (I signal, Q signal).

FIG. 4 is a block diagram showing the internal configuration of the descrambler 64, the despreader 65, and the synthesizer 67. In FIG. 4, reference numeral 100 denotes a complex signal (I signal, Q signal) output from the orthogonal demodulator 63. Multipliers 101 to 104 multiply the identification signal Sdpch, n for identifying the mobile station, and the channel separation spread codes Cd, 1, Cd, 3, Cd, Multipliers 105 and 109 for multiplying 5 and Ccc respectively, respectively, apply spreading codes Cd, 2, Cd, 4, Cd, 6, Cc, and Ccc for channel separation to the Q signal output from the descrambling unit 64. Multipliers 110 to 118 are integrators for time-integrating the output signals of the multipliers 101 to 109 over the spreading code time length.
FIG. 5 is a flowchart showing a communication method according to Embodiment 1 of the present invention.

Next, the operation will be described.
An operation when the mobile station 2 transmits data to the base station 1 will be described.
Here, for convenience of explanation, a case will be described in which data of six data channels and control data of two control channels are transmitted.
First, distributor 51 of mobile station 2 distributes data DPDCH of dedicated data channels in parallel and outputs data DPDCH1 to DPDCH6 of a plurality of data channels (step ST1).

When the distributor 51 outputs data DPDCH1 to DPDCH6 of a plurality of data channels, the spreader 52 spreads the channel for the data DPDCH1 to DPDCH6 of the data channel and the control data DPCCH and ADPCCH of the control channel. Spectrum spreading is performed by multiplying the code (step ST2).
That is, the multipliers 71 to 76 of the spreader 52 multiply the data DPDCH1 to DPDCH6 of the plurality of data channels output from the distributor 51 by the spreading codes Cd, 1 to Cd, 6 for channel separation, The multiplier 77 of the spreader 52 multiplies the control data DPCCH of the control channel by the spread code Cc for channel separation, and the multiplier 78 of the spreader 52 adds control data ADPCCH of the control channel to be newly added. Is multiplied by a spreading code Ccc for channel separation.

When the multiplier 78 of the spreader 52 multiplies the control data ADPCCH for the control channel by the spreading code Ccc for channel separation, the distributor 53 multiplies the output data of the multiplier 78 by the multipliers 88 and 89 of the scramble unit 54. (Step ST3).
The distribution ratio of the scrambler 54 to the multipliers 88 and 89 may be determined in consideration of the I-axis signal power and the Q-axis signal power. In this example, the distribution ratio is 1: 1. Shall.

The scrambler 54 IQ multiplexes the output signals of the spreader 52 and the distributor 53 to generate a complex signal (I signal, Q signal) (step ST4).
That is, the multipliers 81 to 86 of the scramble unit 54 multiply the output signals of the multipliers 71 to 76 in the spreader 52 by the amplitude coefficient βd for DPDCH, and the multiplier 87 of the scramble unit 54 Is multiplied by the amplitude coefficient βc for DPCCH.
The multiplier 88 of the scrambler 54 multiplies the output signal of the distributor 53 by the amplitude coefficient βcc (I) for ADPCCH, and the multiplier 89 of the scrambler 54 applies to the output signal of the distributor 53. And multiply by the amplitude coefficient βcc (Q) for ADPCCH.

The amplitude coefficients βcc (I) and βcc (Q) for ADPCCH are determined in consideration of the I-axis signal power and the Q-axis signal power. That is, the signal power of the I signal and the signal power of the Q signal output from the adder 93 are determined to be uniform.
Incidentally, FIG. 6 shows a complex plane when the number of data channels is set to 1. For example, the signal power of the data DPDCH1 is “1.5” and the signal power of the control data DPCCH is “1.0”. If present, the amplitude coefficient for ADPCCH so that the signal power of the I-axis control data ADPCCH (I) is “1.0” and the signal power of the Q-axis control data ADPCCH (Q) is “0.5”. βcc (I) and βcc (Q) are determined.

Next, the adder 90 of the scramble unit 54 adds the output signals of the multipliers 81 to 83, 88, and the adder 91 of the scramble unit 54 adds the output signals of the multipliers 84 to 87, 89.
Further, the multiplier 92 of the scramble unit 54 multiplies the output signal of the adder 91 by an imaginary number j in order to assign the output signal of the adder 91 to the Q axis.
Next, the adder 93 of the scrambler 54 adds the output signal of the adder 90 and the output signal of the multiplier 92, and the multiplier 94 of the scrambler 54 identifies the mobile station with respect to the output signal of the adder 93. Multiplicative identification codes Sdpch, n are multiplied to output complex signals (I signal, Q signal).

When the scrambling unit 54 generates a complex signal (I signal, Q signal) as described above, the modulation unit 55 performs quadrature modulation on the complex signal (I signal, Q signal) to generate a modulation signal (step ST5). ).
When the modulation unit 55 generates a modulation signal, the frequency conversion unit 56 frequency-converts the modulation signal to generate a radio frequency signal, amplifies the radio frequency signal, and outputs the amplified signal to the antenna 57 (step ST6). As a result, a radio frequency signal is transmitted from the antenna 57 to the base station 1.

When the antenna 61 receives the radio frequency signal transmitted from the mobile station 2, the frequency converter 62 of the base station 1 converts the radio frequency signal to output a baseband signal (step ST7).
When the frequency converter 62 outputs the baseband signal, the orthogonal demodulator 63 performs orthogonal demodulation on the baseband signal and outputs a complex signal (I signal, Q signal) (step ST8).

When the orthogonal demodulation unit 63 outputs a complex signal (I signal, Q signal), the descrambling unit 64 multiplies the complex signal (I signal, Q signal) by an identification code for identifying a mobile station (step ST9). ).
That is, the multiplier 100 of the descrambling unit 64 multiplies the complex signal (I signal, Q signal) output from the quadrature demodulation unit 63 by the identification code Sdpch, n for mobile station identification.

The despreader 65 multiplies the output signal of the descrambling unit 64 by a channel separation spreading code to separate the data of each channel (step ST10).
That is, the multipliers 101 to 104 of the despreader 65 multiply the I signal output from the descrambling unit 64 by the channel separation spreading codes Cd, 1, Cd, 3, Cd, 5, Ccc, respectively. The multipliers 105 to 109 of the despreader 65 multiply the Q signal output from the descrambling unit 64 by channel separation spreading codes Cd, 2, Cd, 4, Cd, 6, Cc, and Ccc, respectively. To do.
The integrators 110 to 118 of the despreader 65 control the data channels DPDCH1 to DPDCH6 and the control channel by time-integrating the output signals of the multipliers 101 to 109 over the spreading code time length. Reproduce the data DPCCH.

The data DPDCH1 to DPDCH6 for the data channel are merged by the data channel merger 66 to reproduce the data DPDCH for the dedicated data channel (step ST11).
Further, the output signal of the integrator 113 of the despreader 65 and the output signal of the integrator 118 are combined by the combiner 67 to reproduce the control data ADPCCH for the newly added control channel (step ST12). .

As apparent from the above, according to the first embodiment, when the scrambler 54 IQ multiplexes the output signals of the spreader 52 and the distributor 53 to generate a complex signal (I signal, Q signal), Since the amplitude coefficients βcc (I) and βcc (Q) for ADPCCH are determined in consideration of the signal power of the axis and the signal power of the Q axis, for example, generation of amplifier distortion in the frequency conversion unit 56 And the interference with the adjacent frequency band can be suppressed.

In the first embodiment, six data channels are set. However, when the number of data channels is five or less, the data DPDCH1 is assigned to the I / Q axis in order, and is not necessary. No processing related to the data channel is performed. The number of data channels set is determined by the required communication service and communication speed.

Embodiment 2. FIG.
7 is a block diagram showing a mobile station applied to a communication system according to Embodiment 2 of the present invention, and FIG. 8 is a block diagram showing a base station applied to the communication system according to Embodiment 2 of the present invention. is there. In the figure, the same reference numerals as those in FIG. 1 and FIG.
58 is a selector (IQ multiplexing means) that outputs control data ADPCCH of the control channel after spread spectrum by the spreader 52 to the multiplier 88 or the multiplier 89 of the scrambler 54, and 68 is the integrator 113 of the despreader 65 or It is a selector (IQ separation means) that inputs and outputs control data ADPCCH of the control channel from the integrator 118.

In the first embodiment, the distributor 53 distributes the output data of the multiplier 78 in the spreader 52 to the multipliers 88 and 89 of the scramble unit 54, and the multipliers 88 and 89 of the scramble unit 54 have the signal power of the I signal. As described above, the output signal of the divider 53 is multiplied by the amplitude coefficients βcc (I) and βcc (Q) for ADPCCH so that the signal power of the Q signal becomes uniform. Since the control data ADPCCH of the control channel is allocated to the axis with the smaller signal power, the selector 58 scrambles the output data of the multiplier 78 in the spreader 52 in consideration of the I-axis signal power and the Q-axis signal power. The data may be output to the multiplier 88 or the multiplier 89 of the unit 54.

That is, in TS25.213 of the 3GPP standard, if the number of data channels is set to 1, the data channel is assigned to the I axis (see FIG. 9), and if the number of data channels is set to 2, Each data channel is assigned to the I axis and the Q axis (see FIG. 10), so that the data channels are alternately assigned to the I axis and the Q axis.
Therefore, in the second embodiment, from the viewpoint of balancing the signal power of the I axis and the signal power of the Q axis, the selector 58 of the mobile station 2 has a spreader if the set number of data channels is an odd number. 52, the output data of the multiplier 78 is output to the multiplier 89 of the scramble unit 54, and the control data ADPCCH of the control channel is assigned to the Q axis.

The selector 68 of the base station 1 inputs the control channel control data ADPCCH from the integrator 118 of the despreader 65 in order to obtain the control data ADPCCH of the control channel assigned to the Q axis. Output ADPCCH.
On the other hand, if the set number of data channels is an even number, the selector 58 of the mobile station 2 outputs the output data of the multiplier 78 in the spreader 52 to the multiplier 88 of the scramble unit 54 to control the control channel. Data ADPCCH is assigned to the I axis.

The selector 68 of the base station 1 inputs the control channel control data ADPCCH from the integrator 113 of the despreader 65 in order to obtain control data ADPCCH of the control channel assigned to the I axis, and the control data Output ADPCCH.
Thereby, according to this Embodiment 2, like the said Embodiment 1, generation | occurrence | production of the distortion of the amplifier in the frequency conversion part 56 can be suppressed, for example, and the disturbance to an adjacent frequency band can be suppressed. There is an effect.

In the second embodiment, the axis for allocating the control channel control data ADPCCH according to the set number of data channels is shown. However, the selector 58 of the mobile station 2 determines the signal power of the I axis and The axis to which the control data ADPCCH of the control channel is assigned may be determined by measuring the signal power of the Q axis.

Embodiment 3 FIG.
In the second embodiment, the control channel ADPCCH for assigning the control data to the axis with the smaller signal power out of the I axis and the Q axis has been shown. However, as shown in FIGS. Channel control data ADPCCH may always be assigned to the Q axis. That is, the spreading code length of the control data ADPCCH for the control channel is about 256, which is considered to be the same as the spreading code length of the control data DPCCH for the control channel.

Therefore, the signal power of the control data ADPCCH of the control channel is smaller than the signal power of the data DPDCH1 of the data channel, and compared with the amount of data transmitted on the downlink when considering the use of the Internet, for example. Therefore, it is considered that the amount of data to be transmitted in the uplink is not large, and therefore in many cases where the HSDPA link is set, the number of data channels set may be one.

Here, FIG. 15 to FIG. 20 show the scramble unit 54 when the set number of data channels (indicated by N in the figure) is changed and the control data ADPCCH of the control channel is assigned to the I axis or the Q axis. 7 shows an example of simulation of CCDF (Complementary Cumulative Distribution Function) characteristics in the output waveform. In the figure, “I” indicates a characteristic when the control data ADPCCH is assigned to the I axis, and “Q” indicates a characteristic when the control data ADPCCH is assigned to the Q axis.

The CCDF characteristic indicates the ratio (%) of how much the instantaneous power exceeds the average power in terms of time. As the CCDF characteristic goes to the right, it means that the ratio of instantaneous power that is larger than the average power is larger (power fluctuation is larger). For example, when the number of data channels set is 1 (N = 1) and the characteristics of control channel control data ADPCCH assigned to the Q-axis are viewed, the temporal power is about 3.5 dB or more higher than the average power. The proportion is 0.1%.
As an amplifier, distortion is more likely to occur as a signal with large fluctuations is input, and current consumption increases because linearity is required up to higher power in order to suppress distortion.

As can be seen from FIG. 15, when N = 1 (the data channel is only DPDCH1), the characteristics vary greatly depending on whether the control data ADPCCH is assigned to the I or Q axis. Few. Similarly, the allocation axis with good characteristics is switched according to N, and it can be seen that the CCDF characteristic is better when it is allocated to the Q axis when N is an odd number and to the I axis when N is an even number. . This is consistent with the assignment method in the second embodiment, and it can be seen that this is the best method that can reduce distortion from the viewpoint of CCDF characteristics.
However, compared to the case of N = 1, when N> 1, the difference between the I axis and the Q axis is not large, so it can be considered that the degree of distortion is also small.
Therefore, from the viewpoint of balancing the I-axis signal power and the Q-axis signal power and from the viewpoint of the characteristics of the input signal of the amplifier, the control channel control data ADPCCH together with the control channel control data DPCCH. Even if is assigned to the Q axis, it is considered that there are few problems in practical use.

As described above, when the control data ADPCCH of the control channel is always assigned to the Q axis, the distributor 53, the combiner 67, or the selectors 58 and 68 are not required as shown in FIGS. The effect which can aim at simplification of this is produced.

It is a block diagram which shows the mobile station applied to the communication system by Embodiment 1 of this invention. It is a block diagram which shows the base station applied to the communication system by Embodiment 1 of this invention. It is a block diagram which shows the internal structure of a diffuser, a divider | distributor, and a scramble part. It is a block diagram which shows the internal structure of a descrambling part, a despreader, and a combiner. It is a flowchart which shows the communication method by Embodiment 1 of this invention. It is explanatory drawing which shows a complex plane in case the setting number of the channel for data is one. It is a block diagram which shows the mobile station applied to the communication system by Embodiment 2 of this invention. It is a block diagram which shows the base station applied to the communication system by Embodiment 2 of this invention. It is explanatory drawing which shows a complex plane in case the setting number of the channel for data is one. It is explanatory drawing which shows a complex plane in case the setting number of the channel for data is two. It is a block diagram which shows the mobile station applied to the communication system by Embodiment 3 of this invention. It is a block diagram which shows the base station applied to the communication system by Embodiment 3 of this invention. It is explanatory drawing which shows a complex plane in case the setting number of the channel for data is one. It is explanatory drawing which shows a complex plane in case the setting number of the channel for data is two. It is explanatory drawing which shows the CCDF characteristic of a modulation waveform. It is explanatory drawing which shows the CCDF characteristic of a modulation waveform. It is explanatory drawing which shows the CCDF characteristic of a modulation waveform. It is explanatory drawing which shows the CCDF characteristic of a modulation waveform. It is explanatory drawing which shows the CCDF characteristic of a modulation waveform. It is explanatory drawing which shows the CCDF characteristic of a modulation waveform. It is a conceptual diagram which shows the conventional communication system. It is a block diagram which shows the internal structure of a mobile station. It is a block diagram which shows the internal structure of a diffuser and a scramble part. It is a table | surface figure which shows the value which amplitude coefficient (beta) d and (beta) c can take. It is explanatory drawing which shows a complex plane in case the setting number of the channel for data is one. It is a conceptual diagram which shows the conventional communication system.

Explanation of symbols

51 Distributor (IQ multiplexer), 52 Spreader (IQ multiplexer), 53 Distributor (IQ multiplexer), 54 Scrambler (IQ multiplexer), 55 Modulator (transmitter), 56 Frequency converter (Transmit) Means), 57 antenna (transmitting means), 58 selector (IQ multiplexing means), 61 antenna (receiving means), 62 frequency converting section (receiving means), 63 orthogonal demodulating section (receiving means), 64 de-scrambled section (IQ separation) Means), 65 despreader (IQ separation means), 66 data channel merger (IQ separation means), 67 combiner (IQ separation means), 68 selector (IQ separation means), 71-76 multiplier, 77 multiplication Multiplier, 78 multiplier, 81-86 multiplier, 87 multiplier, 88, 89 multiplier, 90 adder, 91 adder, 92 multiplier, 93 adder, 94 multiplier, 100 multiplier, 1 1-104 multiplier, 105 to 109 multipliers, 110-118 integrator.

Claims (1)

And IQ multiplexing means for generating a complex signal control data of the transmission data and control channel data channel IQ multiplexed with, and a transmitting means for transmitting by modulating the complex signal generated by the IQ multiplexing means In the mobile station, the IQ multiplexing means includes a spreader that performs spectrum spreading on the data of each channel, a scramble unit that performs scramble processing on the IQ multiplexed data of each channel, and an odd number for the data An I-axis adder for adding the transmission data of the channel, a Q-axis adder for adding the transmission data of the even-numbered data channel and the control data of the control channel, and channel separation for each channel data a multiplier for multiplying the spread signal, when adding control data of the control channel, setting the number of data channels is an odd der If, assigned the control data to Q axis, if the set number of data channels is an even number, the mobile station characterized by comprising, a selector for allocating the control data to the I axis.

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