HK1075985B

HK1075985B - Mobile station and transmission method

Info

Publication number: HK1075985B
Application number: HK05108050.5A
Authority: HK
Inventors: 庭野和人
Original assignee: 三菱电机株式会社
Priority date: 2002-01-29
Filing date: 2005-03-30
Publication date: 2009-08-21

Description

Mobile station and transmission method

Technical Field

The present invention relates to a mobile station, a base station, a communication system, and a communication method for performing data communication at high speed.

Background

As mobile wireless communication systems represented by cellular phones, a variety of communication systems called 3 rd generation are adopted by ITU (international telecommunications union) as IMT-2000, and in W-cdma (wideband Code Division Multiple access), commercial operations have been started in japan in 2001.

The W-CDMA scheme is a 3GPP (3 GPP) as a standardization body for the purpose of obtaining a communication speed of about 2mbps (bit per second) per mobile station^rdGenerationPartnership Project), the original specification was determined as a standard Release, Release 99 (Release1999) Release, summarized in 1999.

Fig. 1 is a general conceptual diagram illustrating a conventional communication system, in which 1 denotes a base station, 2 denotes a mobile station that performs wireless communication with the base station 1, 3 denotes a downlink used when the base station 1 transmits data to the mobile station 2, and 4 denotes an uplink used when the mobile station 2 transmits data to the base station 1.

Fig. 2 is a block diagram showing an internal configuration of the mobile station 2, where 11 is a Data DPDCH for allocating individual Data channels (Dedicated Physical Data channels) in parallel, an allocator 12 is a spreader for spreading data DPDCH1 to DPDCH6 and Control data DPCCH of a Control CHannel (DedicatedPhysical Control CHannel) output from the allocator 11 by multiplying them by a spreading code for CHannel separation, 13 is a scrambling unit for generating complex signals (I signal, Q signal) by IQ multiplexing an output signal of the spreader 12, 14 is a modulation unit for orthogonally modulating the complex signals (I signal, Q signal) generated by the scrambling unit 13 and generating modulation signals, 15 is a frequency conversion unit for frequency-converting the modulation signals generated by the modulation unit 14 and outputting radio frequency signals, and 16 is an antenna for transmitting the radio frequency signals output from the frequency conversion unit 15.

FIG. 3 is a diagram showing the internal configuration of the spreader 12 and the scrambler 13, and 21 to 26 are diagrams showing the multiplication of the data DPDCH1 to DPDCH6 outputted from the distributor 11 by the spreading code C for channel separation_d，1～C_d，6The multiplier 27 is used for multiplying the control data DPCCH of the control channel by the spreading code C for channel separation_cThe multipliers 31 to 36 are amplitude coefficients beta for multiplying the output signals of the multipliers 21 to 26 by DPDCH_d37 is an amplitude coefficient beta for multiplying the output signal of the multiplier 27 by DPCCH_cThe multiplier of (1).

Reference numeral 38 denotes an adder for adding the output signals of the multipliers 31 to 33, 39 denotes an adder for adding the output signals of the multipliers 34 to 37, 40 denotes a multiplier for multiplying the output signal of the adder 39 by an imaginary number j, 41 denotes an adder for adding the output signal of the adder 38 and the output signal of the multiplier 40, and 42 denotes an adder for multiplying the output signal of the adder 41 by an identification code S for identifying a mobile station_dpch，nAnd outputs complex signals (I signal, Q signal).

The operation will be described below.

The 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. 1, data is transmitted using the uplink 4, and when 1 mobile station 2 uses the uplink 4 in the W-CDMA standard, data of 6 data channels can be transmitted at maximum according to the communication speed required for the communication service.

For convenience of explanation, a case of transmitting data of 6 data channels and control data of 1 control channel will be described.

First, the allocator 11 of the mobile station 2 allocates the data DPDCHs of the individual data channels in parallel and outputs the data DPDCHs 1 to 6 of a plurality of data DPDCHs.

Multipliers 21 to 26 of the spreader 12 output data DPDCH1 to DPDCH6 of a plurality of data channels for data at the distributor 11, and multiply the data DPDCH1 to DPDCH6 by spreading code C for channel separation_d，1～C_d，6The multiplier 27 of the spreader 12 multiplies the control data DPCCH of the control channel by the spreading code C for channel separation_c。

The scrambler 13 IQ multiplexes the output signal of the spreader 12 to generate a complex signal (I signal, Q signal).

That is, multipliers 31 to 36 of the scramble unit 13 multiply output signals of multipliers 21 to 26 of the expander 12 by an amplitude coefficient β for DPDCH_dThe multiplier 37 of the scramble unit 13 multiplies the output signal of the multiplier 27 of the spreader 12 by the amplitude coefficient β for DPCCH_c。

Here, FIG. 4 shows the amplitude coefficient β_d、β_cA chart of values that can be taken. Coefficient of amplitude beta_d、β_cCoefficients for determining power ratios between the data DPDCHs 1 to 6 and the control data DPCCH are defined in ts25.213v3.6.0(2001-06) (Release1999) of the 3GPP standard. In addition, the right side of the table is the amplitude coefficient β_d、β_cDesirable values.

Subsequently, the adder 38 of the scrambler 13 adds the output signals of the multipliers 31 to 33, and the adder 39 of the scrambler 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 distribute the output signal of the adder 39 to the Q-axis.

Here, data DPDCH1, DPDCH3, and DPDCH5 are assigned to the I axis, data DPDCH2, DPDCH4, and DPDCH6 are assigned to the Q axis, and a data channel assignment method for the I/Q axis is defined in TS25.213 of the 3GPP standard.

Then, the adder 41 of the scramble unit 13 adds the output signal of the adder 38 and the output signal of the multiplier 40, and the multiplier 42 of the scramble unit 13 multiplies the output signal of the adder 41 by the identification code S for mobile station identification_dpch，nAnd outputs complex signals (I signal, Q signal).

As described above, the modulating unit 14 generates complex signals (I signal and Q signal) in the scrambling unit 13, and then quadrature modulates the complex signals (I signal and Q signal) to generate modulated signals.

The frequency conversion unit 15 generates a modulation signal in the modulation unit 14, frequency-converts the frequency signal to generate a radio frequency signal, amplifies the radio frequency signal, and outputs the amplified radio frequency signal to the antenna 16. Thereby, a radio frequency signal is transmitted from the antenna 16 to the base station 1.

When receiving the radio frequency signal transmitted from the mobile station 2, the base station 1 performs an operation reverse to that of the mobile station 2 to obtain data.

In the above-described conventional example, 6 data channels are set, and when the number of data channels set is 5 or less, the data channels are sequentially allocated to the I/Q axis from the data DPDCH1, and no processing is performed on unnecessary data channels. The number of data channels to be set is determined based on a required communication service and a required communication speed.

Here, fig. 5 is an explanatory diagram showing a complex plane in the case where the set number of data channels is 1.

In this case, the data DPDCH1 of the data channel is allocated on the I axis, and the control data DPCCH of the control channel is allocated on the Q axis.

Thus, since the data DPDCH1 and the control data DPCCH are orthogonal to each other, the base station 1 can separate two channels and perform demodulation.

The data channel setting number can be expressed in the same manner as 2 to 6. Only when the number of data channels is 2 to 6, coaxial channel components can be separated by using a spreading code for channel separation.

In the above-described conventional example, 1 Downlink 3 and 1 uplink 4 are set between the base station 1 and the mobile station 2, but in order to achieve further speeding up of Downlink data transmitted from the base station 1 to the mobile station 2, hsdpa (High Speed Downlink Packet Access) of a Downlink 5 is newly added to the conventional Downlink 3 as shown in fig. 6 (see tr25.858v1.0.0(2001-06) 'High Speed Downlink Packet Access: Physical Layer accessories (Release 5)').

Further, when the downlink 5 is newly added, it is considered that the mobile station 2 transmits response data (ACK/NACK) for downlink high-speed packet data to the base station 1, and as shown in fig. 6, regarding a dedicated control channel (uplink channel 6) for transmitting the response data, the direction of the study is to perform additional multiplexing on the existing uplink 4 after being separated and identified by a spreading code for channel separation, as in the case of the existing control channel. The dedicated control channel is described as "additional DPCCH" in TR 25.858.

Since the conventional communication system is configured as described above, it is necessary to assign a newly added dedicated control channel to the I axis or Q axis, but if the peak power of the I axis or Q axis increases due to assignment of the dedicated control channel to the I axis or Q axis, the modulation unit 14 of the mobile station 2 generates distortion due to use of a nonlinear region of its input-output characteristics in, for example, a built-in quadrature modulator (or quadrature modulation amplifier). Further, if the I-axis signal power and the Q-axis signal power are out of balance, the peak power of the quadrature-modulated signal output from the modulation unit 14 becomes larger than that in the case where the I-axis and the Q-axis are balanced, and for example, when the frequency conversion unit 15 of the mobile station 2 amplifies a radio frequency signal by using a built-in amplifier, distortion occurs due to the use of a nonlinear region of the input/output characteristics thereof. Thus, if distortion occurs in the amplifier and a nonlinear component is output, the nonlinear component interferes with a signal component of an adjacent frequency band, and the adjacent frequency band is disturbed.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a mobile station, a base station, a communication system, and a communication method that can suppress the occurrence of amplifier distortion and suppress interference with adjacent frequency bands.

Disclosure of Invention

When control data of a control channel is added to a mobile station according to the present invention, the control data of the control channel is allocated to an I axis and a Q axis, and IQ multiplexing is performed to generate a complex signal.

This has the effect of suppressing the occurrence of amplifier distortion and suppressing the occurrence of interference in adjacent frequency bands.

When adding control data of a control channel, a mobile station according to the present invention allocates the control data to an I axis and a Q axis in consideration of signal power of the I axis and signal power of the Q axis.

When control data of a control channel is added, a mobile station according to the present invention distributes control data to an I axis and a Q axis so that signal power of the I axis and signal power of the Q axis are uniform.

This has the effect of effectively suppressing the occurrence of amplifier distortion.

When control data of a control channel is added, the mobile station allocates the control data to the axis of which the signal power is smaller, i.e., the I axis and the Q axis.

This has the effect of suppressing the occurrence of amplifier distortion without complicating the structure.

When control data of a control channel is added to a mobile station according to the present invention, the control data is allocated to the Q-axis if the number of data channels is odd, and the control data is allocated to the I-axis if the number of data channels is even.

When control data of a control channel is added, a mobile station according to the present invention allocates the control data to a Q-axis.

This has the effect of reducing the occurrence of amplifier distortion and simplifying the circuit configuration.

When control data of an added control channel is allocated to an I axis and a Q axis, a base station according to the present invention synthesizes and outputs the control data allocated to the I axis and the Q axis.

A communication system according to the present invention generates a complex signal by allocating control data of a control channel to an I axis and a Q axis and performing IQ multiplexing when the control data of the control channel is added by an IQ multiplexing section of a mobile station, and outputs the control data allocated to the I axis and the Q axis by synthesizing the control data when the control data of the added control channel is allocated to the I axis and the Q axis.

A communication method according to the present invention is a communication method in which, when control data of a control channel is added to a mobile station, the control data of the control channel is distributed to an I axis and a Q axis and IQ multiplexing is performed to generate a complex signal, and when the control data of the added control channel is distributed to the I axis and the Q axis, a base station synthesizes and outputs the control data distributed to the I axis and the Q axis.

Drawings

Fig. 1 is a conceptual diagram illustrating a conventional communication system.

Fig. 2 is a block diagram showing an internal configuration of a mobile station.

Fig. 3 is a structural diagram showing the internal structure of the expander and the scrambler.

FIG. 4 shows the amplitude coefficient β_d、β_cA chart of values that can be taken.

Fig. 5 is an explanatory diagram showing a complex plane in the case where the set number of data channels is 1.

Fig. 6 is a conceptual diagram illustrating a conventional communication system.

Fig. 7 is a configuration diagram showing a mobile station applied to the communication system according to embodiment 1 of the present invention.

Fig. 8 is a configuration diagram showing a base station applied to the communication system according to embodiment 1 of the present invention.

Fig. 9 is a block diagram showing the internal configuration of the spreader, distributor, and scrambler.

Fig. 10 is a block diagram showing the internal configuration of a descrambling unit, a despreader, and a synthesizer.

Fig. 11 is a flowchart showing a communication method according to embodiment 1 of the present invention.

Fig. 12 is an explanatory diagram showing a complex plane in the case where the set number of data channels is 1.

Fig. 13 is a configuration diagram showing a mobile station applied to a communication system according to embodiment 2 of the present invention.

Fig. 14 is a configuration diagram showing a base station applied to a communication system according to embodiment 2 of the present invention.

Fig. 15 is an explanatory diagram showing a complex plane in the case where the set number of data channels is 1.

Fig. 16 is an explanatory diagram showing a complex plane in the case where the set number of data channels is 2.

Fig. 17 is a configuration diagram showing a mobile station applied to a communication system according to embodiment 3 of the present invention.

Fig. 18 is a configuration diagram showing a base station applied to a communication system according to embodiment 3 of the present invention.

FIG. 19 shows the number of data channels set to1 case, a plurality of planes.

Fig. 20 is an explanatory diagram showing a complex plane in the case where the set number of data channels is 2.

Fig. 21 is an explanatory diagram showing CCDF characteristics of a modulation waveform.

Fig. 22 is an explanatory diagram showing CCDF characteristics of the modulation waveform.

Fig. 23 is an explanatory diagram showing CCDF characteristics of the modulation waveform.

Fig. 24 is an explanatory diagram showing CCDF characteristics of the modulation waveform.

Fig. 25 is an explanatory diagram showing CCDF characteristics of the modulation waveform.

Fig. 26 is an explanatory diagram showing CCDF characteristics of the modulation waveform.

Detailed Description

In the following, in order to explain the present invention in more detail, the best mode for carrying out the present invention will be explained with reference to the accompanying drawings.

Embodiment mode 1

Fig. 7 is a block diagram showing a mobile station applied to a communication system according to embodiment 1 of the present invention, in which reference numeral 51 denotes an allocator for allocating data DPDCHs of individual data channels in parallel and outputting data DPDCHs 1 to DPDCHs 6 of a plurality of data channels, reference numeral 52 denotes a spreader for spreading data DPDCHs 1 to DPDCHs 6 outputted from the allocator 51 and control data DPCCH of a control channel, ADPCCH (ADPCCH: additional DPCCH) by multiplying the control data ADPCCH by a spreading code for channel separation, reference numeral 53 denotes a divider for allocating control data ADPCCH of the control channel spread by the spreader 52, and reference numeral 54 denotes a scrambler for generating complex signals (I signal and Q signal) from output signals of the IQ multiplexer spreader 52 and the divider 53.

Here, the distributor 51, the spreader 52, the distributor 53, and the scrambler 54 constitute an IQ multiplexing unit.

Reference numeral 55 denotes a modulation unit which orthogonally modulates the complex signal (I signal, Q signal) generated by the scramble unit 54 to generate a modulated signal, 56 denotes a frequency conversion unit which frequency-converts the modulated signal generated by the modulation unit 55 to output a radio frequency signal, and 57 denotes an antenna which transmits the radio frequency signal output from the frequency conversion unit 56.

Here, the modulation unit 55, the frequency conversion unit 56, and the antenna 57 constitute a transmission unit.

Fig. 8 is a configuration diagram showing a base station applied to a communication system according to embodiment 1 of the present invention, in which reference numeral 61 denotes an antenna for receiving a radio frequency signal transmitted from the mobile station 2, reference numeral 62 denotes a frequency conversion unit for frequency-converting the radio frequency signal received by the antenna 61 and outputting a baseband signal, and reference numeral 63 denotes a quadrature demodulation unit for quadrature-demodulating the baseband signal output from the frequency conversion unit 62 and outputting a complex signal (I signal, Q signal).

Here, the antenna 61, the frequency conversion unit 62, and the orthogonal demodulation unit 63 constitute a reception unit.

Reference numeral 64 denotes a descrambler for multiplying the complex signal (I signal, Q signal) outputted from the orthogonal demodulator 63 by the mobile station identification code, 65 denotes a despreader for multiplying the output signal of the descrambler 64 by the channel separation spreading code and separating each channel data, 66 denotes a data channel combiner for combining the data DPDCH1 to DPDCH6 of the data channel and reproducing the individual data channel data DPDCH, and 67 denotes a combiner for combining the control data ADPCCH of the control channel allocated to the I axis and the Q axis.

Here, the descrambling unit 64, the despreader 65, the data channel combiner 66, and the synthesizer 67 constitute an IQ separation unit.

FIG. 9 is a diagram showing the internal configuration of the spreader 52, distributor 53 and scrambler 54, where 71 to 76 denote the multiplication of the data DPDCH1 to DPDCH6 outputted from the distributor 51 by the spreading code C for channel separation_d，1～C_d，677 is multiplying the control data DPCCH of the control channel by the spreading code C for channel separation_cThe multiplier 78 is used to multiply the control data ADPCCH of the newly added control channel by the spreading code C for channel separation_ccThe multipliers 81 to 86 are the amplitude coefficients beta for multiplying the output signals of the multipliers 71 to 76 by DPDCH_d87 is an amplitude coefficient beta for multiplying the output signal of the multiplier 77 by DPCCH_c88, 89 multiplies the output signal of the distributor 53 by the amplitude coefficient beta for ADPCCH_ccThe multiplier of (1).

Reference numeral 90 denotes an adder for adding the output signals of the multipliers 81 to 83 and 88, 91 denotes an adder for adding the output signals of the multipliers 84 to 87 and 89, 92 denotes a multiplier for multiplying the output signal of the adder 91 by an imaginary number j, 93 denotes an adder for adding the output signal of the adder 90 and the output signal of the multiplier 92, and 94 denotes an adder for multiplying the output signal of the adder 93 by an identification code S for identifying a mobile station_dpch，nAnd outputs complex signals (I signal, Q signal).

Fig. 10 is a block diagram showing the internal configuration of the descrambling unit 64, the despreader 65 and the synthesizer 67, and in the figure, 100 is a multiplication of the complex signal (I signal, Q signal) output from the descrambling unit 64 by the identification code S for identifying the mobile station_dpch，n101 to 104 are multipliers for multiplying the I signals outputted from the descrambler 64 by the spreading codes C for channel separation_d，1、C_d，3、C_d，5、C_cc105 to 109 are multipliers for multiplying the Q signals outputted from the descramble unit 64 by spreading codes C for channel separation_d，2、C_d，4、C_d，6、C_c、C_ccThe multipliers 110 to 118 are integrators which integrate the output signals of the multipliers 101 to 109 with the spreading code time length.

The operation will be described below.

The operation when the mobile station 2 transmits data to the base station 1 will be described.

For convenience of explanation, a case of transmitting data of 6 data channels and control data of 2 control channels will be described.

First, the allocator 51 of the mobile station 2 allocates the data DPDCHs of the individual data channels in parallel and outputs the data DPDCHs 1 to 6 of a plurality of data DPDCHs (step ST 1).

After the distributor 51 outputs the data DPDCH1 to DPDCH6 of the plurality of data channels, the spreader 52 spreads the data DPDCH1 to DPDCH6 of the data channels, the control data DPCCH and the ADPCCH of the control channel by the spreading code for channel separation (step ST 2).

That is, multipliers 71 to 76 of spreader 52 multiply data DPDCH1 to DPDCH6 of a plurality of data channels outputted from distributor 51 by spreading code C for channel separation_d，1～C_d，6The multiplier 77 of the spreader 52 multiplies the control data DPCCH of the control channel by the spreading code C for channel separation_cThe multiplier 78 of the spreader 52 multiplies the control data ADPCCH of the newly added control channel by the spreading code C for channel separation_cc。

The distributor 53 multiplies the control data ADPCCH of the control channel by the spreading code C for channel separation at the multiplier 78 of the spreader 52_ccThereafter, the output data of the multiplier 78 is distributed to the multipliers 88 and 89 of the scramble unit 54 (step ST 3).

Here, the distribution ratio of the multipliers 88, 89 to the scramble portion 54 may be determined in consideration of the I-axis signal power and the Q-axis signal power, and in this example, it is assumed that the distribution is performed at a ratio of 1: 1.

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 ST 4).

That is, the multipliers 81 to 86 of the scramble unit 54 multiply the output signals of the multipliers 71 to 76 of the spreader 52 by the amplitude coefficient β for DPDCH_dThe multiplier 87 of the scrambling unit 54 multiplies the output signal of the multiplier 77 of the spreader 52 by the amplitude coefficient β for DPCCH_c。

The multiplier 88 of the scrambler 54 multiplies the output signal of the distributor 53 by the amplitude coefficient β for ADPCCH_cc(I)The multiplier 89 of the scrambler 54 multiplies the output signal of the distributor 53 by the amplitude coefficient β for ADPCCH_cc(Q)。

Here, the amplitude coefficient β for the ADPCCH_cc(I)、β_cc(Q)Determined by considering the I-axis signal power and the Q-axis signal power. Even if the signal power of the I signal and the signal power of the Q signal outputted from the scramble unit 54 are determined to be uniform.

For example, fig. 12 shows a complex plane in the case where the number of data channels is 1, and if the signal power of the data DPDCH1 is "1.5" and the signal power of the control data DPCCH is "1.0", for example, the amplitude coefficient β for the ADPCCH is determined so that the signal power of the control data ADPCCH (I) on the I axis is "1.0" and the signal power of the control data ADPCCH (Q) on the Q axis is "0.5"_cc(I)、β_cc(Q)。

Subsequently, the adder 90 of the scrambler 54 adds the output signals of the multipliers 81 to 83 and 88, and the adder 91 of the scrambler 54 adds the output signals of the multipliers 84 to 87 and 89.

The multiplier 92 of the scrambler 54 multiplies the output signal of the adder 91 by an imaginary number j in order to distribute the output signal of the adder 91 to the Q-axis.

Then, the adder 93 of the scramble unit 54 adds the output signal of the adder 90 to the output signal of the multiplier 92, and the multiplier 94 of the scramble unit 54 multiplies the output signal of the adder 93 by the identification code S for mobile station identification_dpch，nAnd outputs complex signals (I signal, Q signal).

As described above, the modulating unit 55 generates complex signals (I signal and Q signal) by the scrambling unit 54, and then quadrature modulates the complex signals (I signal and Q signal) to generate modulated signals (step ST 5).

After the modulation unit 55 generates the modulation signal, the frequency conversion unit 56 frequency-converts the frequency signal to generate a radio frequency signal, amplifies the radio frequency signal, and outputs the amplified radio frequency signal to the antenna 57 (step ST 6). Thereby, 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 frequency-converts the radio frequency signal and outputs a baseband signal (step ST 7).

The quadrature demodulation section 63 outputs the baseband signal from the frequency conversion section 62, and then quadrature demodulates the baseband signal to output complex signals (I signal and Q signal) (step ST 8).

The descrambler 64 outputs the complex signal (I signal, Q signal) from the quadrature demodulator 63, and multiplies the complex signal (I signal, Q signal) by the identification code for identifying the mobile station (step ST 9).

That is, the multiplier 100 of the descrambler 64 multiplies the complex signal (I signal, Q signal) outputted from the quadrature demodulator 63 by the identification code S for identifying the mobile station_dpch，n。

The despreader 65 multiplies the output signal of the descrambler 64 by a spreading code for channel separation to separate data of each channel (step ST 10).

That is, multipliers 101 to 104 of despreader 65 multiply the I signal outputted from descrambler 64 by spreading code C for channel separation_d，1、C_d，3、C_d，5、C_ccTo solveMultipliers 105 to 109 of the spreader 65 multiply the Q signal outputted from the descramble unit 64 by spreading codes C for channel separation, respectively_d，2、C_d，4、C_d，6、C_c、C_cc。

Integrators 110 to 118 of the despreader 65 time-integrate the output signals of the multipliers 101 to 109 over the spreading code time length, thereby reproducing the data DPDCH1 to DPDCH6 of the data channel and the control data DPCCH of the control channel.

Here, the data DPDCHs 1 to 6 of the data channels are combined by the data channel combining unit 66, and the data DPDCHs of the individual data channels are reproduced (step ST 11).

Then, 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, and the control data ADPCCH of the newly added control channel is reproduced (step ST 12).

As is clear from the above description, according to embodiment 1, when the scrambling unit 54 IQ-multiplexes the output signals of the spreader 52 and the distributor 53 to generate complex signals (I signal and Q signal), the amplitude coefficient β for ADPCCH is determined in consideration of the signal power of the I axis and the signal power of the Q axis_cc(I)、β_cc(Q)Therefore, for example, the distortion of the amplifier in the frequency conversion unit 56 can be suppressed, and the interference with the adjacent frequency band can be suppressed.

Here, in embodiment 1, the case where 6 data channels are set is described, and when the number of data channels set is 5 or less, the data channels are sequentially allocated to the I/Q axis from the data DPDCH1, and processing on unnecessary data channels is not performed. The number of data channels to be set is determined based on a required communication service and a required communication speed.

Embodiment mode 2

Fig. 13 is a configuration diagram showing a mobile station applied to a communication system according to embodiment 2 of the present invention, and fig. 14 is a configuration diagram showing a base station applied to the communication system according to embodiment 2 of the present invention. In the drawings, the same reference numerals as those in fig. 7 and 8 denote the same or corresponding parts, and therefore, the description thereof will be omitted.

Reference numeral 58 denotes a selector (IQ multiplexer) which outputs the control data ADPCCH of the control channel spread by the spreader 52 to the multiplier 88 or the multiplier 89 of the scrambler 54, and 68 denotes a selector (IQ separator) which inputs and outputs the control data ADPCCH of the control channel from the integrator 113 or the integrator 118 of the descrambler 64.

In the above embodiment 1, the description is made such that the distributor 53 distributes the output data of the multiplier 78 in the spreader 52 to the multipliers 88 and 89 in the scramble unit 54, and the multipliers 88 and 89 in the scramble unit 54 make the signal power of the I signal and the signal power of the Q signal uniform by the amplitude coefficient β for the ADPCCH_cc(I)、β_cc(Q)The selector 58 may output the output data of the multiplier 78 in the spreader 52 to the multiplier 88 or the multiplier 89 in the scrambler 54 in consideration of the signal power of the I axis and the signal power of the Q axis, because the control data ADPCCH of the control channel is distributed to the axis having smaller signal power in the I axis and the Q axis by multiplying the output signal of the distributor 53.

That is, if the number of data channels specified in TS25.213 of the 3GPP standard is 1, the data channels are allocated to the I axis (see fig. 15), and if the number of data channels is 2, the data channels are allocated to the I axis and the Q axis (see fig. 16), and the data channels are alternately allocated to the I axis and the Q axis.

In view of balancing the I-axis signal power and the Q-axis signal power, in embodiment 2, if the set number of data channels is an odd number, the selector 58 of the mobile station 2 outputs the output data of the multiplier 78 in the spreader 52 to the multiplier 89 of the scrambler 54, and distributes the control data ADPCCH of the control channel to the Q-axis.

The selector 68 of the base station 1 receives the control data ADPCCH for the control channel from the integrator 118 of the descrambler 64 and outputs the control data ADPCCH so as to obtain the control data ADPCCH for the control channel allocated to the Q-axis.

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 scrambler 54, and allocates the control data ADPCCH of the control channel to the I axis.

The selector 68 of the base station 1 receives the control data ADPCCH for the control channel from the integrator 113 of the descrambler 64 and outputs the control data ADPCCH so as to obtain the control data ADPCCH for the control channel allocated to the I axis.

Thus, according to embodiment 2, as in embodiment 1, for example, the distortion of the amplifier in the frequency conversion unit 56 can be suppressed, and the interference with the adjacent frequency band can be suppressed.

Here, in embodiment 2, the case where the axis to which the control data ADPCCH for the control channel is allocated is determined based on the set number of data channels is described, but the axis to which the control data ADPCCH for the control channel is allocated may be determined by the selector 58 of the mobile station 2 by measuring the signal power of the I axis and the signal power of the Q axis.

Embodiment 3

In embodiment 2, the control data ADPCCH of the control channel is assigned to the axis having the smaller signal power of the I axis and the Q axis, but the control data ADPCCH of the control channel may be always assigned to the Q axis as shown in fig. 19 and 20.

That is, the spreading code length of the control data ADPCCH in the control channel is considered to be about 256, and is similar to the control data DPCCH in the control channel.

Therefore, the signal power of the control data ADPCCH of the control channel is small compared to the signal power of the data DPDCH1 of the data channel, and when the use of the internet or the like is considered, for example, it can be considered that the amount of data transmitted in the uplink is not large compared to the amount of data transmitted in the downlink, and therefore, in many cases where the HSDPA link is set, the set number of the data channel can be considered to be 1.

Here, fig. 21 to 26 show simulation examples of ccdf (complementary temporal distribution function) characteristics in the output waveform of the scrambler 54 in the case where the number of settings of the data channel is changed (shown by N in the figure) and the control data ADPCCH of the control channel is assigned to the I axis or the Q axis. In the figure, "I" represents a characteristic in the case where the control data ADPCCH is assigned to the I axis, and "Q" represents a characteristic in the case where the control data ADPCCH is assigned to the Q axis.

The CCDF characteristics indicate a ratio (%) of instantaneous power to how much the average power rises in time. The CCDF characteristics mean that the ratio of the instantaneous power to the average power is larger (the power fluctuation is larger) toward the right side. For example, the set number of data channels is 1(N is 1), and the proportion of time from the average power to the instantaneous power as high as 3.5dB or more is 0.1% in view of the characteristic that the control data ADPCCH of the control channel is allocated to the Q axis.

As an amplifier, distortion is more likely to occur as a signal with larger input fluctuation increases, and high power linearity is required to suppress the distortion, and thus power consumption increases.

As is clear from fig. 21, when N is 1 (data channel DPDCH1 only), the characteristic is greatly different depending on whether the allocation axis of the control data ADPCCH is I or Q, and distortion is less likely to occur when the control data ADPCCH is allocated to the Q axis. It is also clear that the distribution axis with good characteristics changes depending on N, and that the CCDF characteristics are good for the distribution of Q-axis if N is odd and I-axis if N is even. This is clearly the most preferable method for reducing distortion from the viewpoint of CCDF characteristics, in accordance with the allocation method in embodiment 2 described above.

However, in the case where N >1, the difference between the I axis and the Q axis is not large, and thus the difference in the degree of distortion is considered to be small, as compared with the case where N is 1.

From the viewpoint of the balance between the I-axis signal power and the Q-axis signal power and the input signal characteristic of the amplifier, it is considered that there is little problem in practical use even if the control data ADPCCH of the control channel is assigned to the Q-axis.

As described above, when the control data ADPCCH of the control channel is always allocated to the Q axis, as shown in fig. 17 and 18, the allocator 53, the synthesizer 67, and the selectors 58 and 68 are not required, and the circuit configuration can be simplified.

Industrial applicability

As described above, the mobile station, the base station, the communication system, and the communication method according to the present invention are suitable for transmitting and receiving IQ-multiplexed complex signals when data communication is performed at high speed.

Claims

1. A mobile station is provided with

An IQ multiplexing unit for IQ multiplexing transmission data of a data channel, control data of a control channel, and control data of a control channel for downlink high-speed packet access, and generating a complex signal;

a transmitting unit that modulates and transmits the complex signal generated by the IQ multiplexing unit, the transmitting unit comprising:

the IQ multiplexing unit comprises

A selector for alternately allocating transmission data of the data channels to the I axis and the Q axis, allocating control data of the control channel to the Q axis, allocating control data of the control channel for downlink high-speed packet access to the Q axis when the set number of the data channels is an odd number, and allocating control data of the control channel for downlink high-speed packet access to the I axis when the set number of the data channels is an even number;

a scrambling unit for performing IQ multiplexing of data of each channel and then performing scrambling processing;

a spreader for spreading data of each channel before IQ-multiplexing the data; and

an allocator for allocating transmission data to the plurality of channels before spreading.

2. A transmission method comprises

An IQ multiplexing step of IQ multiplexing transmission data of a data channel, control data of a control channel, and control data of a control channel for downlink high-speed packet access to generate a complex signal;

a transmission step of modulating and transmitting the complex signal generated in the IQ multiplexing step, the transmission step comprising:

the IQ multiplexing step includes

A selection step of alternately allocating transmission data of a data channel to the I axis and the Q axis, allocating control data of a control channel to the Q axis, and selectively allocating control data of a control channel for downlink high-speed packet access, that is, allocating control data of a control channel for downlink high-speed packet access to the Q axis when the set number of data channels is an odd number, and allocating control data of a control channel for downlink high-speed packet access to the I axis when the set number of data channels is an even number;

a scrambling step of performing scrambling processing after IQ multiplexing of data of each channel;

a spreading step of spreading data of each channel before IQ multiplexing; and

and an allocation step of allocating the transmission data to the plurality of channels before spreading.