JP2002084258A - Communication apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wireless unit that has a higher noise eliminating capability so as to enhance the communication quality. SOLUTION: A decoding section 30 of the wireless unit of this invention configures a RAKE receiver, a common pilot signal correlation calculation section 111 calculates a correlation of common pilot signals with respect to a reception path, a replica signal generating section 121 generates replica signals of a common pilot signal, a primary synchronizing signal and a secondary synchronizing signal depending on the correlation value, and adders 200, 210 subtracts the replica signals by the reception paths from a received signal. A user signal correlation calculation section 141 and a synchronization detection section 151 extract a user signal with respect to one reception path from the received signal from which the replica signal is subtracted and an adder 220 applies RAKE synthesis to the extracted user signals by the reception paths.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio equipment used in code division multiple access communication using a direct spreading method, and more particularly to a technique for removing noise during reception.

[0002]

2. Description of the Related Art Recently, CDMA (Code Division M) has been proposed as a communication system that can effectively use radio wave resources.
The multiple access (code division multiple access) system is in the spotlight. Regarding this method, the formulation of standards, technical development, and practical application are being actively pursued. One of the standards that defines this method is ITU (Inte
national Telecommunication
on Union) in 2000,
DS (Direct Sequence) C
There is a DMA system.

In wireless communication according to the DS-CDMA system, a base station spreads a user signal addressed to each mobile station by using a spreading code selected so as to have a low correlation with each mobile station, and spreads the spread signal. Transmit simultaneously using one carrier. That is, it transmits the code division multiplexed user signal. The mobile station receives the signal, and despreads the received signal using a spreading code for the mobile station, thereby extracting a user signal addressed to the mobile station from the received signal.

In order to accurately extract a user signal in the despreading process, it is necessary to apply a sequence of spreading codes to the received signal at the same timing as that applied when spreading the signal. In order to perform the synchronous detection, the base station transmits a common control signal for synchronous detection whose content is known in parallel with the transmission of the user signal.
For spreading the signal, a spreading code having a low correlation with a spreading code applied to a user signal addressed to any mobile station is used.

[0005] A mobile station extracts a common control signal from a received signal by despreading the received signal using a spreading code for the common control signal. Since the data of the signal is known, the transmission phase of the base station can be detected from the extracted common control signal, and the user signal is accurately extracted by synchronously detecting the user signal according to the detected timing. I have.

[0006] The standard specifies that a base station transmit this common control signal using a common pilot channel. Hereinafter, this signal is referred to as a common pilot signal. The common pilot signal will be described with reference to FIG. When transmission diversity is not performed, as shown in FIG. 5 (a), the base station generates one common pilot signal in which a symbol whose I and Q components are both 1 (A = 1 + j in complex notation) is repeated. Fig. 5
The transmission is performed in the pattern of (a). A base station having two antennas and performing transmission diversity transmits a common pilot signal shown in FIG. 5 (a) from one antenna, and outputs a common pilot signal every two symbols as shown in FIG. 5 (b) from the other antenna. A
And -A are transmitted.

The common pilot channel includes:
There is a primary common pilot channel transmitted in all areas (cells) covered by one base station, and a secondary common pilot channel transmitted in an arbitrary area in one cell. If the common pilot signal is obtained from the base station, the phase of the synchronous detection of the user signal is detected based on the signal if the common pilot signal is obtained, or based on the common pilot signal obtained from the primary common pilot channel otherwise.

[0008] Another type of synchronization signal is an initial synchronization signal used when a mobile station starts communicating with a base station. The mobile station obtains the initial synchronization signal and obtains information necessary for establishing communication with the base station. The standard specifies that the base station transmits the initial synchronization signal using a primary synchronization channel and a secondary synchronization channel. Hereinafter, a signal transmitted using the primary synchronization channel is referred to as a primary synchronization signal, and a signal transmitted using the secondary synchronization channel is referred to as a secondary synchronization signal.

FIG. 6A shows a primary synchronization signal, and FIG.
Shows a secondary synchronization signal. The base station transmits both signals one symbol intermittently at the beginning of each slot (10 symbol time) period. As described above, the mobile station extracts a user signal with high accuracy by synchronously detecting a received signal in accordance with information based on the common pilot channel and timing detected based on the synchronization channel. The effect of the user signal addressed to another mobile station, which is noise with respect to the user signal addressed to the own station, is removed by the despreading process.

[0010]

However, in the above-mentioned receiving apparatus of the prior art, in a multipath environment and during handover, the cross-correlation power between the common pilot signal and the user signal between paths and between cells is reduced. Since it is no longer 0, there is a problem that the common pilot signal appears as noise in the despreading of the user signal, and the decoded signal deteriorates.

This is because in a multipath environment, the autocorrelation power of the used spreading code does not become 0 due to the delay time between each path. This is because cross-correlation power exists in In addition, in order to respond to requests from users for improved communication quality, such as higher quality call sound quality and improved connection stability, the ability to remove a wide range of noise components is improved without specifying the situation. Is required.

In view of the above problems, it is an object of the present invention to provide a radio having higher noise removal capability and improving communication quality.

[0013]

Means for Solving the Problems To solve the above problems, (1) a radio device of the present invention receives a code-division multiplexed signal and converts a first signal and a second signal contained in the signal. The wireless device extracts a first signal included in a received signal, and extracts a second signal from a signal obtained by subtracting the first signal from the received signal.

(2) Further, the wireless device of (1) includes a first extracting means for extracting the first signal by despreading the received signal using the first code, and First
Spreading means for spreading using a code; subtracting means for subtracting the spread signal from the received signal;
Second extraction means for extracting a second signal by despreading using a code may be provided.

(3) In the wireless device according to (1) or (2), the first extracting means has a plurality of extracting sections, extracts a first signal for each receiving path, and Is
A plurality of spreading units, the first signal extracted for each reception path is spread using a first code, and the subtraction means subtracts all signals spread for each reception path from the reception signal, The second extraction means has a plurality of extraction units, and a second extraction unit is provided for each reception path.
The signals may be extracted and the extracted signals may be combined.

(4) Further, in the wireless device according to any one of (1) to (3), the first signal may be a common control signal, and the second signal may be a user signal. (5) In the wireless device according to any one of (1) to (4), the code-division-multiplexed signal further includes a third signal.
Signal, the radio further includes third spreading means for spreading a third signal in accordance with the extracted first signal, and the subtraction means converts the further spread third signal from the received signal. May be reduced.

(6) In the wireless device according to (5), the third signal may be a common control signal different from the first signal. (7) A wireless communication terminal according to the present invention is a wireless communication terminal that performs code division multiplex communication by a direct spreading method, and extracts a first signal by despreading a received signal using a first code. Extracting means, spreading means for spreading the extracted first signal using the first code, subtracting means for subtracting the spread signal from the received signal, and despreading the subtracted received signal using the second code. To extract the second signal.
Extraction means.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION
It is a wireless communication terminal that performs code division multiplex communication by the direct spreading method by the DS-CDMA method. <Overall Configuration> FIG. 1 is a block diagram showing the configuration of the wireless device 1. The wireless device 1 includes an antenna 10, a wireless unit 20, a decoding unit 30 having a spread code generation unit, a voice processing unit 40, a modulation unit 50 having a spread code generation unit, a control unit 70, a speaker 80, a microphone 85, and a display unit 90. , Key part 95
And communicates with the base station by the DS-CDMA system.

The radio section 20 acquires a high-frequency signal received by the antenna 10, amplifies the signal using a low-noise amplifier or the like, and supplies the amplified signal to the decoding section 30. The radio unit 20 amplifies the signal obtained from the modulation unit 50 using a high power amplifier or the like, and transmits the amplified signal from the antenna 10. The decoding unit 30 obtains a received signal from the radio unit 20, despreads a common pilot signal component included in the received signal using a common pilot signal spreading code to obtain a correlation value, and further spreads the correlation value. A replica signal is created, the timing is adjusted, the received signal is subtracted from the received signal, and the user signal is extracted by despreading the subtracted signal using a spreading code for the user signal generated by the spreading code generator. Then, the extracted signal is supplied to the audio processing unit 40.

The audio processing unit 40 converts the signal obtained from the decoding unit 30 into an analog audio signal by D / A conversion, supplies the converted analog audio signal to the speaker 80, and emits the sound from the speaker 80. In addition, the audio processing unit 40 acquires an analog audio signal from the microphone 85, converts the acquired analog audio signal into a digital signal by performing A / D conversion, and supplies the digital signal to the modulation unit 50.

The modulating unit 50 spreads the digital signal obtained from the audio processing unit 40 using the spreading code for the user signal generated by the spreading code generating unit, and supplies the spread signal to the radio unit 20. . The display unit 90 is a display device realized by a liquid crystal display panel or the like. Key part 9
Reference numeral 5 denotes an input device having numeric keys (numerical key, * key, and # key), an on-hook key, an off-hook key, and the like.

The control unit 70 is, specifically, a CPU (Cen).
(Tral Processing Unit) and a memory, and the CPU controls the entire wireless device by executing a program recorded in the memory. Here, each component except the decoding unit 30 is realized using a conventional technique, and a detailed description thereof will be omitted. <Decoding Unit 30> FIG. 2 is a block diagram showing the configuration of the decoding unit 30. The decoding unit 30 includes signal processing units 101 to 10
3. It comprises adders 200 to 220. The signal processing unit 101 includes a common pilot signal correlation calculation unit 111, a replica signal generation unit 121, a channel estimation unit 131, a user signal correlation calculation unit 141, and a synchronous detection unit 151. The signal processing units 102 and 103 are the signal processing unit 1
01.

The signal processing units 101 to 103 constitute rake receivers, each of which receives a reception signal from the radio unit 20, and processes the reception signal in accordance with each reception path as follows. The common pilot signal correlation calculator 111 despreads the received signal using the spreading code for the common pilot signal, thereby calculating a correlation value for each symbol for the common pilot signal corresponding to each one reception path,
The correlation value is supplied to replica signal generation section 121 and channel estimation section 131.

The channel estimating unit 131 calculates the correlation value based on the correlation value obtained from the common pilot signal correlation calculating unit 111.
A channel estimation amount for the reception path is obtained. More specifically, when the sequence of correlation values of 10 symbols acquired in one slot period is γ1, γ2, γ3, γ4, γ5, γ6, γ7, γ8, γ9, γ10, (γ1 + γ2), (γ3 + γ4 ), (Γ5 + γ6), (γ7 + γ8),
(γ9 + γ10) and (γ1-γ2), (γ4-γ3), (γ5-γ
6) The channel estimation amount is calculated from (γ8−γ7) and (γ9−γ10). When the base station does not perform transmission diversity, a common pilot signal is transmitted by one transmission antenna in the symbol pattern of FIG. 5A, so that (γ1 + γ2), (γ3 + γ4), (γ5 + γ6), (γ7
+ Γ8) and (γ9 + γ10) show the correlation value of symbol A, but (γ1−γ2), (γ4−γ3), (γ5−γ6), (γ8−γ
7), (γ9−γ10) have no correlation value because the symbols cancel each other out. On the other hand, when the base station performs transmission diversity, (γ1 + γ2), (γ3 + γ4), (γ5 + γ6), (γ7 +
In (γ8) and (γ9 + γ10), the correlation value of the symbol A on the transmitting antenna 1 side appears, and (γ1−γ2), (γ4−γ3),
(γ5−γ6), (γ8−γ7), and (γ9−γ10) show correlation values on the transmitting antenna 2 side. That is, the common pilot signal on the transmitting antenna 1 side can be extracted by adding the above-mentioned symbols regardless of the presence or absence of the transmission diversity, and the transmitting antenna 2 can be extracted by the above-mentioned symbol subtraction.
Side common pilot signal can be extracted, and thereby a channel estimate for each of the two transmission antennas can be determined.

The replica signal generation section 121 spreads the correlation value obtained from the common pilot signal correlation calculation section 111 to generate a replica signal of the common pilot signal synchronized with the reception signal received via the reception path. And outputs the result to the adder 200. The adder 200 sums the replica signals generated for each reception path by the replica signal generation units 121 to 123, and the adder 210 subtracts the summed replica signal from the received signal, and outputs the signal after the subtraction to the user. Signal correlation calculators 141 to 143 and synchronous detector 1
51 to 153.

The user signal correlation calculator 141 receives the subtracted signal from the adder 210 and despreads the signal using a spreading code for a user signal, thereby obtaining a user signal corresponding to the reception path. A correlation value for each symbol is calculated, and the correlation value is supplied to the synchronous detection unit 151. The synchronous detection unit 151 synchronously detects the signal after the subtraction according to the phase delay determined by the correlation value and the channel estimation amount acquired from the channel estimation unit 131, and demodulates the user signal.

The adder 220 includes synchronous detectors 151 to 15
3 rake-combines the user signal demodulated for each reception path to obtain a decoded signal. Here, each component except the replica signal generation units 121 to 123 is realized using a conventional technique, and a detailed description thereof will be omitted. <Replica signal generator> FIG.
FIG. 21 is a block diagram showing a configuration of a first embodiment 21. The replica signal generator 121 includes a common pilot replica signal generator 31.
0, primary synchronous replica signal generator 320, secondary synchronous replica signal generator 330, and adder 340
Consists of Replica signal generators 122 and 123
Is configured in the same manner as the replica signal generation unit 121.

Common pilot replica signal generating section 310
Obtains a correlation value calculated for a common pilot signal corresponding to one reception path from the common pilot signal correlation calculation unit 111, and generates a spread common pilot signal corresponding to the reception path based on the correlation value. Restore,
The signal is output to adder 340. Similarly, primary synchronization replica signal generation section 320 restores the spread primary synchronization signal corresponding to one reception path, and outputs the signal to adder 340.

Secondary synchronous replica signal generator 330
Restores the spread secondary synchronization signal corresponding to one reception path, and outputs the signal to the adder 340. The adder 340 adds the signals obtained from the respective signal generation units. <Common Pilot Replica Signal Generation Unit> FIG. 4 is a block diagram showing a configuration of common pilot replica signal generation unit 310. Common pilot replica signal generation section 310
Is composed of an average amplitude calculator 410, a spreading code generator 430, a spreading calculator 440, an oversampling unit 450, and a waveform shaping unit 460.

Input to a common pilot signal correlation calculator,
The output is described as a complex number composed of an in-phase component and a quadrature component, and can be described on the I and Q complex planes. In the case where transmission diversity is executed, as for the symbols of the common pilot signal, only the symbols transmitted from the base station transmission antenna 2 change in code, as shown in FIG. Here, it is assumed that the phase of the reception point of the common pilot signal when transmission diversity is performed is as shown in FIG.
A case where a replica signal is generated in slot # 0 and is used in slot # 1 to remove noise will be described.

The replica signal generation unit obtains a replica signal as follows. First, in slot # 0, only the symbol period in which the output of the base station transmission antenna 2 is (A) is averaged for a certain period. The content of the symbol added here is a combination of the symbol from the transmission antenna 1 and the symbol from the transmission antenna 2. One slot is composed of 10 symbols, but the average time is one slot time (= 0.667 ms).
Is used, it is too late to generate a replica signal at the next slot timing, so that the averaging up to the eighth symbol is performed. As shown in FIG. 8, since there are four symbols in which the output of the transmitting antenna 2 is (A) in eight symbols, the averaging of four symbols is eventually performed. The average value is α.

Similarly, only the symbols for which the output of the antenna 2 is (-A) are averaged for a certain period. This average value is set to β. Using these α and β, a signal having the following sequence of amplitudes is generated. α / 256, β / 256, β / 256, α / 256, α
/ 256, β / 256, β / 256, α / 256, α /
256, β / 256 where 256 is the spreading factor of the common pilot signal, which can be converted to an amplitude level signal.

The arrangement of the symbols is such that the symbol pattern on the transmitting antenna 2 side of slot # 1 is -A, A, A, -A, -A, A, A, -A, -A, A It depends. A signal in which the above value becomes amplitude information and subjected to complex spreading processing using a spreading code of the common pilot signal at the corresponding timing is used as a replica signal. That is, the average value of A and -A obtained in slot # 0 is used as the original data of the replica signal in slot # 1. In this method,
In order to obtain the original data of the replica signal for each slot, the averaging was performed in eight symbol periods.
When the original data of the replica signal is updated for each slot, it is possible to perform the averaging of 10 + 8 = 18 symbol periods. However, if the averaging is performed for an excessively long time, a calculation error of the replica signal itself may occur due to a frequency error that is a tracking error of the automatic frequency control. For example, when the frequency error of the clock source in the mobile device is 0.1 ppm, the phase rotation amount generated during one slot period is about ± 48 °. In the two-slot period, there is a possibility that a phase rotation amount twice as large as this may occur. However, if the phase is rotated by 90 ° or more, the result of the averaging may be affected. Can be inferred.
Since the spreading code used in the common pilot signal correlation calculating unit and the spreading code used in the replica signal generating unit are the same code string, it is possible to share the output code of the spreading code generator.

The oversampling section 450 oversamples the signal input from the spread calculating section 440 at a cycle twice or four times the chip cycle. The oversampled signal has a staircase waveform as shown in FIG. The waveform shaping unit 460 generates a spread common pilot signal corresponding to one reception path by passing the oversampled signal through a low-pass filter. <Primary Synchronous Replica Signal Generating Unit> The primary synchronous replica signal generating unit 320 is configured similarly to the common pilot replica signal generating unit 310. Again, FIG.
, The primary synchronous replica signal generator 3
Regarding the function of each component in the case of 20, the differences from the above will be mainly described. Here, it is assumed that the primary common pilot channel is used as the common pilot channel.

Since the same amount of signal attenuation occurs in the primary common pilot signal and the synchronous channel signal, the average amplitude value of the synchronous channel signal can be estimated from the received average symbol of the primary common pilot. Both the primary common pilot and the synchronization channel signal are broadcast to the entire cell and can be transmitted with a substantially constant amplitude ratio. Here, the ratio of the synchronization channel signal to the primary common pilot signal is κ. That is, the amplitude information of the primary synchronization signal can be estimated by multiplying the average value α obtained from the average amplitude calculation section 410 by κ.

An amplitude sequence of κα / 256, 0, 0, 0, 0, 0, 0, 0, 0, 0 is set for each slot. The spread signal is used to supply the spread signal to the oversampling section 450. The oversampling section 450 oversamples the signal input from the spreading operation section 440 at a cycle twice or four times the chip cycle, and the waveform shaping section 460 passes the oversampled signal through a low-pass filter. Thus, a spread primary synchronization signal corresponding to one reception path is generated. <Secondary Synchronous Replica Signal Generating Unit> The secondary synchronous replica signal generating unit 330 is configured similarly to the primary synchronous replica signal generating unit 320. The operation of each component is the same as that of the primary synchronization replica signal generation unit 320 except that the spreading code generation unit 430 generates a spreading code for a secondary synchronization signal, and a detailed description is omitted. <Summary> As described above, the radio 1 constitutes a rake receiver, calculates a correlation of a common pilot signal for each reception path, and, according to the correlation value, a common pilot signal, a primary synchronization signal, and a secondary synchronization signal. A replica signal is generated by spreading and adding the synchronization signal. The replica signal is a noise component for the user signal.
The wireless device 1 extracts a user signal by subtracting the generated replica signals for the plurality of reception paths from the reception signal, and despreading the reception signal after the subtraction for each reception path,
Rake combining the extracted user signals.

With this configuration, the radio 1 extracts the user signal from the received signal from which the common pilot signal, the primary synchronization signal, and the secondary synchronization signal, which are noise with respect to the user signal, have been removed. And the communication quality is improved.

[0038]

(1) The radio of the present invention is a radio that receives a code-division multiplexed signal and extracts a first signal and a second signal included in the signal, and includes the received signal. And extracting a second signal from the signal obtained by subtracting the first signal from the received signal. According to this configuration, when the first signal is a common pilot signal and the second signal is a user signal, the radio sets the user signal from the received signal from which the common pilot signal, which is noise, has been removed from the user signal. Because of the extraction, it has a high noise removal capability and the communication quality is improved.

(2) Further, the wireless device of (1) comprises a first extracting means for extracting a first signal by despreading a received signal using a first code, and a first extracting means for extracting the extracted first signal. First
Spreading means for spreading using a code; subtracting means for subtracting the spread signal from the received signal;
Second extraction means for extracting a second signal by despreading using a code may be provided.

According to this configuration, the same effect as the above (1) can be obtained. (3) In the wireless device of (1) or (2),
The first extracting unit has a plurality of extracting units and extracts a first signal for each receiving path, and the spreading unit has a plurality of spreading units and converts the first signal extracted for each receiving path. Spreading using a first code, the subtraction means subtracts all signals spread for each reception path from a reception signal, and the second extraction means
A plurality of extraction units, for extracting a second signal for each reception path,
The extracted signals may be combined.

According to this configuration, since the user signals corresponding to the plurality of reception paths are extracted and combined from the reception signals from which the common pilot signals corresponding to the plurality of reception paths have been removed, higher noise can be obtained in a multipath environment. The removal ability is exhibited, and the communication quality is further improved. (4) In the wireless device according to any one of (1) to (3), the first signal is a common control signal, and the second signal is a common control signal.
The signal may be a user signal.

According to this configuration, the same effect as the above (1) can be obtained. (5) In the wireless device according to any one of (1) to (4), the code-division-multiplexed signal further includes a third signal.
Signal, the radio further includes third spreading means for spreading a third signal in accordance with the extracted first signal, and the subtraction means converts the further spread third signal from the received signal. May be reduced.

According to this configuration, when the third signal is the primary synchronization signal and the secondary synchronization signal, the wireless device converts the user signal from the received signal from which both the noise signals have been removed with respect to the user signal. Since extraction is performed, in addition to the effect of the above (1), it has higher noise removal capability and communication quality is improved. (6) In the wireless device according to (5), the third signal may be a common control signal different from the first signal.

According to this configuration, the same effect as (6) is obtained. (7) A wireless communication terminal according to the present invention is a wireless communication terminal that performs code division multiplex communication by a direct spreading method, and extracts a first signal by despreading a received signal using a first code. Extracting means, spreading means for spreading the extracted first signal using the first code, subtracting means for subtracting the spread signal from the received signal, and despreading the subtracted received signal using the second code. To extract the second signal.
Extraction means.

According to this configuration, the same effect as the above (1) can be obtained in the wireless communication terminal. In this embodiment, the configuration in the case of a voice call has been described. However, even in the case of performing data communication, the effect of noise removal according to the present invention can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a wireless device 1.

FIG. 2 is a block diagram showing a configuration of a decoding unit 30.

FIG. 3 is a block diagram illustrating a configuration of a replica signal generation unit 121.

FIG. 4 is a block diagram showing a configuration of a common pilot replica signal generator 310.

FIG. 5A shows a common pilot signal. (B) shows a common pilot signal.

FIG. 6A shows a primary synchronization signal. (B) shows a secondary synchronization signal.

FIG. 7 shows the phase of a reception point of a common pilot signal during transmission diversity.

FIG. 8 is a diagram illustrating average values α and β according to the present embodiment.

[Explanation of symbols]

 Reference Signs List 1 radio 10 antenna 20 radio unit 30 decoding unit 40 audio processing unit 50 modulation unit 70 control unit 80 speaker 85 microphone 90 display unit 95 key unit 101 to 103 signal processing unit 111 to 113 common pilot signal correlation calculation unit 121 to 123 replica Signal generators 131 to 133 Channel estimator 141 to 143 User signal correlation calculator 151 to 153 Synchronous detector 200 to 220 Adder 310 Common pilot replica signal generator 320 Primary synchronous replica signal generator 330 Secondary synchronous replica signal generator 340 Adder 410 Average amplitude calculation unit 430 Spread code generation unit 440 Spread calculation unit 450 Oversampling unit 460 Waveform shaping unit

Claims (7)

[Claims] 1. A communication device for receiving a code-division multiplexed signal and extracting a first signal and a second signal included in the signal, extracting a first signal included in a received signal, and A second signal is extracted from a signal obtained by subtracting a second signal from a received signal. 2. The communication device according to claim 1, wherein the communication device despreads the received signal using a first code to perform first spreading.
First extracting means for extracting a signal; spreading means for spreading the extracted first signal using a first code; subtracting means for subtracting the spread signal from the received signal; The communication device according to claim 1, further comprising: a second extraction unit configured to extract a second signal by performing despreading using a code. 3. The first extracting unit has a plurality of extracting units and extracts a first signal for each reception path, and the spreading unit has a plurality of spreading units and is extracted for each reception path. The first signal is spread using a first code, the subtracting means subtracts all signals spread for each reception path from the received signal, the second extracting means has a plurality of extracting units, The communication device according to claim 1, wherein a second signal is extracted for each reception path, and the extracted signals are combined. 4. The communication device according to claim 1, wherein the first signal is a common control signal, and the second signal is a user signal. 5. The code division multiplexed signal further includes a third signal, and the communication device further includes a third spreading unit that spreads the third signal according to the extracted first signal. The communication device according to any one of claims 1 to 4, further comprising: a subtracting unit that subtracts a further spread third signal from a received signal. 6. The communication device according to claim 5, wherein the third signal is a common control signal different from the first signal. 7. A communication apparatus for performing code division multiplex communication by a direct spreading method, wherein a first signal is despread by using a first code to perform a first signal.
First extracting means for extracting a signal; spreading means for spreading the extracted first signal using a first code; subtracting means for subtracting the spread signal from the received signal; And a second extracting means for extracting a second signal by despreading using a code.