JPH0927796A - Code multiplex reception equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the expansion of circuit scale and the increase of cost by performing inverse diffusion/demodulation to irreducibly minimum code channels at first reception equipment and performing inverse diffusion/ demodulation to the other required code channels at second reception equipment. SOLUTION: First reception equipment 201 detects the phase difference of a received carrier wave and a regenerative carrier wave from a received signal and generates the timing of inverse spectrum diffusion and demodulation. Then, the reception equipment 201 supplies a PN code signal to second reception equipment 202 as needed corresponding to a phase information signal expressing the detected phase difference and the signal of the generated timing. The signal received at the reception equipment 202 is multiplied with the output of a PN generator 310 by a multiplier 309 and supplied to a pilot channel extracter 302, data channel extracter 303 and second-(n)th reception equipment from 304 to 305. In this case, the extracter 302 performs the inverse diffusion to a pilot channel signal and generates the phase information signal containing the information of phase difference between the received carrier wave and the regenerative carrier wave and the timing signal containing the information of advance/delay in processing timing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to code multiplexing (CD
M) system communication or broadcasting system. More specifically, a code division multiple access (CDMA) system cellular standardized in the United States and the like, and a standardization P
The present invention relates to a technique for performing high-speed data transmission using a plurality of code channels in a system such as CS.

[0002]

2. Description of the Related Art In the CDMA system, a specific code is assigned to each line, a modulated wave of the same carrier frequency is spread by this code and transmitted to the same repeater, and each code is synchronized on the receiving side to obtain the desired code. This is a method for identifying the line.

This system is characterized in that it does not require an initial connection process and can communicate directly for each call as long as the codes are determined for each other, and is excellent in confidentiality and interference resistance.

In a CDMA cellular system using this method, a plurality of channels transmitted by each base station are multiplexed using the same frequency channel.

In the forward link (from the base station to the mobile station) of the CDMA cellular system, the pilot
There are four types of code channels: channel, sync channel, paging channel, and traffic channel.

The pilot channel is a channel in which a PN code is repeatedly sent without containing data and is used for synchronization acquisition, maintenance and clock recovery of a mobile terminal. The sync channel is used for matching time information and a long-period PN code between the base station and the mobile station.

The paging channel is a channel used for transmitting information necessary for handoff, terminal call information at the time of incoming call, and traffic channel allocation information. The traffic channel is a channel that transmits voice information used during a call.

FIG. 9 illustrates the transmitter of the base station. In CDMA digital cellular, these channels are multiplexed by changing the spreading code to be multiplied with the data and sent at the same frequency. In this system, a code obtained by multiplying a PN code and a Walsh code becomes a spread code, and each channel is generated by changing the Walsh code.

The Walsh code of the pilot channel is always zero, and the PN code is transmitted as it is.
Therefore, the detection of the PN code transmitted by the base station means checking the timing of the spread code of the pilot channel.

FIG. 10 shows an example of a circuit structure configured to demodulate a plurality of code channels based on a conventional CDMA digital cellular system. However, although demodulation for a plurality of channels is shown in the figure, in the current CDMA cellular system, data is not transmitted using a plurality of code channels for one user. .

In the CDMA cellular shown in FIG. 10, there is a code channel which is not modulated by data but is modulated by only a PN code, which is called a pilot channel. Thus, there are multiple code channels modulated by data (this is referred to as a "data channel").

The received signal is multiplied by the output of the PN code generator 110 in the multiplier 109 and then the pilot signal
Channel extractor 102, data channel extractor 1
03, 104, 105.

The pilot channel extractor 102 is
The signal of the pilot channel is despread to generate a phase information signal representing the phase difference between the received carrier and the reproduced carrier and supplied to each data demodulator (106, 107, 108). This phase information signal is used in the data demodulator for phase correction when demodulating the data of each code channel supplied from the data channel extractor (103, 104, 105). The pilot channel extractor 102 also detects the advance / delay of processing timing and sends advance / delay information to the timing control circuit 101.

The timing control circuit 101 generates a timing signal based on the information on the advance / lag of the processing timing described above. The timing signal generated by the timing control circuit 101 is used for each data channel extractor (10
2, 103, 105) and each data demodulator (106, 1)
07, 108) as operation timing.

In order to demodulate a plurality of code-multiplexed code channels, a data channel extractor and a data demodulator for extracting the code channels must be provided for each code channel.

[0016]

At present, in CDMA cellular, a code multiplex receiver has a spectrum despreader and a data channel extractor and a data demodulator for only one channel.

In order to perform communication at a high data rate using a plurality of code channels in the future, a plurality of data channel extractors and demodulators are built in as described above, and a plurality of code channels (data channels) are included. Need to receive.

In general, a CDMA cellular terminal device is composed of an integrated circuit in order to miniaturize the circuit. However, when receiving a plurality of data channels, the circuit scale becomes large, so that the entire circuit is included in one chip. There is a possibility that it will not be delivered and will be realized by dividing it into multiple chips. Further, the number of code channels may change depending on the purpose, and it is impossible to incorporate a despreader and a demodulator more than necessary.

[0019]

In order to solve the above-mentioned problems, according to the present invention, when demodulating a plurality of code channels from a code-multiplexed received signal, the minimum required code channel is determined. The second receiver (the third receiver, if necessary) can be incorporated into one receiver and add a code channel according to the purpose.

Further, according to the present invention, the devices after the second receiving device do not include the circuit for detecting the phase difference between the received carrier wave and the reproduced carrier wave, the timing control circuit, and the PN code generating circuit, and the first device. By receiving and operating the phase information signal, the timing signal, and the PN code signal from the circuit, the circuit scale can be reduced.

As described above, by preparing the optional devices (second, third, ...) For code multiplexing, the first device has a basic function (for example, demodulates only one code channel). Only needs to be supported, so
The device can be realized at low cost.

By receiving the common information required for despreading / demodulation from the first device, the optional device can reduce unnecessary circuits, reduce the circuit scale, and realize the cost reduction of the optional device.

[0023]

1 is an overall configuration diagram showing an example of a code-multiplexed signal receiving apparatus. This receiving device includes a first receiving device 201 and a second receiving device 202.
Actually, a plurality of second receiving devices may exist. In the figure, the received signal is input to the first receiving device 201 and the second receiving device 202.

The first receiver 201 detects the phase difference between the received carrier and the reproduced carrier from the received signal, performs spectrum despreading, generates demodulation timing, and demodulates a specific code channel. Then, the first receiving device 20
Reference numeral 1 supplies a phase information signal representing the detected phase difference, a generated timing signal, and a PN code signal as necessary to the second receiving device 202.

The second receiving device 202 is the first receiving device 20.
1 receives the phase information signal, the timing signal, and the PN code signal as required, and demodulates the coded channel different from that of the first receiving apparatus 201 from the received signal.

FIG. 2 is a second block diagram of the entire receiver for code-multiplexed signals. Also in this case, the receiving device is composed of the first receiving device 201 and the second receiving device 202. Actually, a plurality of second receiving devices may exist.

The first receiving device 201 detects the phase difference between the received carrier and the reproduced carrier from the received signal to create a phase information signal, generates despreading / demodulation timing, demodulates and demodulates a specific code channel. Output a signal. In addition, the first receiving device 201, the phase information signal, the timing signal,
And a signal obtained by multiplying the received signal by the PN code signal is output to the second receiving device 202.

The second receiving device 202 is connected to the first receiving device 20.
1, the phase information signal, the timing signal, and the signal obtained by multiplying the received signal by the PN code signal are received, and the coded channel different from that of the first receiving apparatus 201 is demodulated from the received signal.

FIG. 3 shows an embodiment of the first receiving device 201 of FIGS. 1 and 2 and related second, third ... Receiving devices. The received signal is multiplied by the output of PN generator 310 and multiplier 309 to obtain pilot channel extractor 30.
2, the data channel extractor 303, and the second receiver 304 to the nth receiver 305. The pilot channel extractor 302 constitutes a despreading circuit for the received signal, despreads the pilot channel signal,
A phase information signal including phase difference information between the received carrier wave and the reproduced carrier wave and a timing signal including advance / lag information of processing timing are generated.

The phase information signal is the data of the first receiving device.
The signal is applied to the channel extractor 303 and the data demodulator 306, and is output to the outside of the first receiving device.
Data channel extractors (304, 305) and data demodulators (307, 30) of the receiving device to the nth receiving device
8) and their data demodulators (306, 30)
7, 308) are the respective data channel extractors (303,
It is used for phase correction when demodulating the data of each code channel from the output of 304, 305).

On the other hand, the pilot channel extractor 30
The signal of the advance or lag of the processing timing detected in 2 is supplied to the timing control circuit 301, and the timing control circuit 301 constitutes the despreading circuit of the first receiving device and the pilot channel extractor 302 and the data channel extractor 303. And a timing signal to the data demodulator 306.

This timing signal is taken out of the first receiving device, and the data channel extractor (304, 305) and the data demodulator (3) of the receiving device after the second receiving device.
07, 308) is used as a timing signal for controlling the operation timing.

In the above description, the data channel extractor 303 and the data demodulator 3 which constitute the first receiving device.
06 is indispensable, but the data channel extractors 304 to 305 and the data demodulators 307 to 308 constituting the second receiving device and later can be added as needed.

FIG. 4 shows the second receiving device 201 of FIG.
An embodiment will be described. The received signal is multiplied by the output of the PN code generator 410 by the multiplier 409 and supplied to the data channel extractor 403. Data channel extractor 4
The output of 03 is input to the data demodulator 406 to demodulate the specific code channel.

Comparing this circuit with the circuit of FIG. 3 described above, this circuit differs from the first receiving device of FIG. 3 in that there is no pilot channel extractor. for that reason,
The data demodulator 406 of the first receiving device is different from the data demodulators of the receiving devices after the second receiving device.

The data demodulator 406 detects the phase difference between the received carrier and the reproduced carrier contained in the despread data and generates a phase information signal. This phase information signal is used by the data demodulator 406 itself to demodulate the phase difference data, and is output to the outside of the first receiving device and supplied to other receiving devices.

The timing control circuit 4 outputs the lead / lag signal of the processing timing output from the data demodulator 406.
01, and the timing signal generated by the timing control circuit 401 is supplied to the data channel extractor 403 and the data demodulator 406 to control the operation timing of these circuits. The timing signal output from the timing control circuit 401 is supplied to the outside of the first receiving device and is also supplied to the data channel extractor and the data demodulator of another receiving device.

The signal received by the first receiving device is multiplied by the multiplier 4
At 09, the product from the PN code generator is multiplied to generate a product signal of the received signal and the PN code signal, which is supplied to the data channel extractor 403 and output to the outside of the first receiving device. , At the input of the data channel extractor of another receiving device.

When other PN code generators are provided in the second, third, etc. receivers, the product signal of the above-mentioned received signal and PN code signal is not sent out, and the reception signal is received by each receiver. Connect so that signals are supplied in parallel. Further, when only the multiplier is provided in the second and subsequent receiving devices, the PN code signal from the PN code generator 410 of the first receiving device is the second one.
It is supplied to the subsequent receiving devices.

FIG. 5 shows an embodiment of the second receiving device 202 in the circuit configuration of FIG. Shown here are multiple data channel extractors and multiple data demodulators for demodulating multiple code channels. Since the data channel extractors 501, 502, 503 and the data demodulators 504, 505, 506 perform the same operation, only the data channel extractor 501 and the data demodulator 504 will be described here.

When the product signal of the received signal and the PN code signal is received from the first receiving device, this signal is supplied to the data channel extractors 501, 502 and 503. If the received signal is directly supplied to the second and subsequent receiving devices, the received signal is first sent to the multiplier 509,
There, the signals from the PN code generator are multiplied and the output is input to the data channel extractor 501.
The output of the data channel extractor 501 is input to the data demodulator 504 and data demodulation is performed.

In this case, instead of providing the PN code generator 510, the P generated by the PN code generator of the first receiving apparatus is used.
The N code signal may be received and input to the multiplier 509. When there are a plurality of second and subsequent receiving devices, P
The N code generator may be provided individually for each receiving device, or one N code generator may be provided commonly for those receiving devices.

FIGS. 6 to 8 are explanatory views for explaining a portion of the circuit for producing the product signal of the above-mentioned received signal and PN code signal. FIG. 6 shows a first PN code multiplication circuit 509 of FIG.
The above embodiment is described together with the subsequent despreading circuit. Here, the Walsh code is an all-zero code in the case of pilot channel extraction, and is a code assigned to each in the case of data channel extraction.

In the circuit of FIG. 6, the PN code is input from the first receiving device 201. The received signal is multiplied by the PN code in the multiplier 601, and the product of the received signal and the PN code is output. The signal formed by this product is despread by multiplying the signal from the Walsh code generator in the subsequent circuit and integrating the result by the integrator 604, and the desired pilot signal and data signal are extracted. .

FIG. 7 shows the second embodiment of the PN code multiplication circuit 509 of FIG. 5 together with the subsequent despreading circuit. The PN code generator 703 is a code generator provided in the second receiving device and generates a PN code. If there are third, fourth, ... Receiving devices, this PN code generator may be provided individually for each receiving device, or may be provided in common to them. The received signal is multiplied by the PN code in the multiplier 701, and the product signal is output. Note that the subsequent Walsh code generator 704, multiplier 702, and accumulator 705.
The point that despreading and signal extraction is performed is the same as above.

FIG. 8 shows the case where the PN code generator is not provided in the receiving apparatus of FIG. 5 and the product signal of the reception signal of the first receiving apparatus and the PN code is input. The signal obtained by multiplying the received signal by the PN code is multiplied by the Walsh code signal generated by the Walsh code generator 801 in the multiplier 802, and the length of one symbol is integrated and output.

[0047]

In the CDM receiver, when despreading and demodulating a plurality of code channels, only the minimum necessary code channels are despread and demodulated by the first receiver, and the code that is further required depending on the purpose. Channel despreading
Even if a device that uses only one code channel such as a current cellular terminal is realized by suppressing an increase in the circuit scale of the first receiving device by performing demodulation by the receiving devices after the second receiving device, the reception is performed. The increase in cost required to make the device can be suppressed.

Further, the second receiving device omits part or all of the carrier recovery circuit (the phase difference detection circuit between the received carrier and the recovered carrier) and the timing control circuit which are originally necessary for despreading / demodulation, and the first receiving device is omitted. By performing despreading / demodulation using device information, it is possible to suppress an increase in circuit scale of the second receiving device and suppress an increase in device cost.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a circuit configuration of a code multiplex receiving apparatus of the present invention.

FIG. 2 is a block diagram showing another example of the circuit configuration of the code multiplex receiving apparatus of the present invention.

FIG. 3 is a first circuit diagram of a code multiplex receiver of the present invention.
It is a block diagram which shows an example of a receiver.

FIG. 4 is a first block diagram of the circuit configuration of the code multiplex receiver of the present invention.
It is a block diagram which shows the other example of a receiver.

FIG. 5 is a second part of the circuit configuration of the code multiplex reception device of the present invention.
It is a block diagram which shows an example of a receiver.

FIG. 6 is a second circuit configuration of the code multiplex receiver of the present invention.
It is a block diagram which shows an example of the circuit which produces | generates the product of a received signal and a PN code, and a despreading circuit of a receiver.

FIG. 7 shows a second part of the circuit configuration of the code multiplex receiver of the present invention.
It is a block diagram which shows the other example of the circuit which makes the product of a received signal and a PN code, and a despreading circuit of a receiver.

FIG. 8 shows a second part of the circuit configuration of the code multiplex receiver of the present invention.
It is a block diagram which shows the example of the despreading circuit of a receiver.

FIG. 9 is a block diagram of a transmission side circuit of a base station for code multiplex communication.

FIG. 10 is a block diagram of a receiving side circuit of a mobile station for code multiplex communication.

[Explanation of symbols]

 201 first receiving device 202 second receiving device

Claims (6)

[Claims] 1. Communication in which a modulated wave of the same carrier frequency is spectrum-spread with a specific code assigned to each line and transmitted to the same repeater, and each code is synchronized on the receiving side to identify a desired line. A code multiplex receiver in the system, which detects a phase difference between a PN code generator, a multiplier that produces a product signal of a reception signal and a PN code, a reception carrier wave and a reproduction carrier wave, and outputs a phase information signal. A circuit for outputting a timing signal by detecting the advance / delay of processing timing, a data channel extractor, and a first receiver equipped with a data demodulator, and the phase information signal and the timing signal from the first receiver. A code multiplex receiving device including a circuit for receiving the signal, a second receiving device including a data channel extractor, and a data demodulator. 2. The code multiplex receiving apparatus according to claim 1, wherein the circuit for outputting the phase information signal and the timing signal of the first receiving apparatus despreads the pilot channel in the received signal and, as a result, A code multiplex receiving device adapted to output phase difference information and timing adjustment information of the generated carrier wave, to be used for demodulation of its own data channel and to be supplied to the second receiving device. 3. The code multiplex receiving apparatus according to claim 1, wherein the second receiving apparatus receives the phase information signal from the first receiving apparatus and supplies the phase information signal to its own data demodulator and the timing. A code multiplex reception device that receives a signal and supplies it to its own data channel extractor and data demodulator to despread the data channel in the received signal to extract the data channel and perform demodulation. 4. The code multiplex receiving apparatus according to claim 3, wherein the circuit for despreading in the second receiving apparatus multiplies the received signal by the PN code signal input from the first receiving apparatus and produces a product signal. And a circuit for multiplying the product signal by the output of the Walsh code generator built in the second receiver, and a circuit for accumulating a signal for one symbol. . 5. The code multiplex receiving apparatus according to claim 3, wherein the despreading circuit of the second receiving apparatus multiplies an output of a PN code generator incorporated in the second receiving apparatus by a received signal, A code multiplex receiving apparatus characterized by performing spectrum despreading by multiplying this by an output of a Walsh code generator built in the second receiving apparatus and integrating signals for one symbol. 6. The code multiplex receiving apparatus according to claim 3, wherein the despreading circuit of the second receiving apparatus receives the second received signal from the product signal of the received signal and the PN code signal received from the first receiving apparatus. A code multiplex receiving apparatus including a circuit for multiplying an output of a Walsh code generator built in the apparatus and integrating a signal for one symbol.