JPH0923170A - Data demodulating method and spread spectrum communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the circuit scale of a spread spectrum communication system and to reduce the size, power consumption and cost of the system. SOLUTION: The spread spectrum communication system includes a data generation part 1, an S/P conversion part 3, multipliers 5 to 9, modulators 11 to 15, delay elements 17 to 21, a PN generator 13, a modulator 25, a local signal generator 35, a multiplexer 27, a frequency conversion part 29, a power amplification part 31, and an antenna 33. Plural modulated/diffused data M1 to M3 are delayed at the same time interval and multiplied and the multiplied transmission signal is transmitted. A receiver repeats operation for multiplying reference modulated data based upon an unmodulated data having the shortest delay time by unmodulated data following the unmodulated data to be the source of the reference modulated data and outputting the multiplied signal as an updated reference modulated data. Thereby circuits to be used for demodulation can be reduced and the circuit scale can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data demodulation method and a spread spectrum communication system for performing multiplexed high speed communication, and more particularly to a data demodulation method and a spread spectrum communication system capable of reducing a circuit scale.

[0002]

2. Description of the Related Art FIG. 13 is a schematic block diagram showing a transmitter in a conventional spread spectrum communication system.

In FIG. 13, a transmitter in a conventional spread spectrum communication system includes a data generator 1 and an S / P.
Converter 3, multipliers 5, 7, 9, modulators 11, 13, 1
5, delay elements 17, 19, 21, PN generator 23, modulator 25, multiplexer 27, frequency converter 29, power amplifier 3
1, an antenna 33 and a local signal generator 35.

As the conventional data communication, communication using a narrow band modulation system is generally put into practical use. Although these can realize demodulation in a receiver with a relatively small circuit, they have a drawback that they are weak against multipath and narrow band colored noise like indoors (office or factory).

On the other hand, a spread spectrum communication system spreads the spectrum of data by a spread code,
Since transmission is performed over a wide band, there is an advantage that these disadvantages can be eliminated.

In Japan, IS in the 2.45 GHz band is also used.
It has been approved for use in the M band and is about to be put into practical use.

In this band, the recognized band is the 26 MHz band, and the spreading factor is 10 or more. Therefore, for example, when a modulation method is used for BPS, the data rate that can be transmitted is 1.3 MH.
It was about z.

On the other hand, high-speed communication is desired, and in order to realize this, it is necessary to perform multiplex transmission.

In this case, there is a delay multiplexing method as one method. This method is characterized by fast synchronization. A conventional spread spectrum communication system adopting such a delay multiplex system will be described.

In FIG. 13, the data generated by the data generator 1 is an S / P converter (serial / parallel converter).
By 3, it is converted into a 3-bit parallel signal, for example. Each of the converted parallel signals is multiplied by the same spreading code from the PN generator 23 by the multipliers 5 to 9, and then the local signals from the local signal generator 35 are PSK by the modulators 11 to 15. Delay element 1 that is modulated and has different delay times (τ1, τ2, τ3)
It is given to the multiplexer 27 via 7-21.

On the other hand, the spread code from the PN generator 23 is given to the modulator 25 as it is, and the local signal generator 35.
PSK-modulates the local signal from and is combined with the outputs from the delay elements 17 to 21 by the multiplexer 27.

The output of the multiplexer 27 is frequency converted into an RF signal by the frequency converter 29, and the power amplifier 3
The power is amplified by 1 and then transmitted by the antenna 33.

FIG. 14 is a schematic block diagram showing a receiver in a conventional spread spectrum communication system.

In FIG. 14, the receiver in the conventional spread spectrum communication system includes an antenna 51, frequency conversion units 53, 167, 169, 171, 173, 175 and 175.
177, 179, 181, delay elements 161, 163, 1
65, distributors 151, 153, 155, 157, 15
9, correlators 183, 185, 187, 189, 19
1, 193, 195, 197, multipliers 199, 201,
203, 205, 207, 209 and adders 211, 21
3, 215, data demodulation circuits 217, 219, 221,
It includes a local signal generator 69 and a P / S conversion circuit 223.

In FIG. 14, the signal transmitted from the transmitter shown in FIG. 13 is received by the antenna 51, converted into an intermediate frequency signal by the frequency conversion unit 53, and then distributed into four by the distributor 151.

The distributed one output is the distributor 1 as it is.
53, and the remaining three distributed outputs are delayed by the same delay time (τ1, τ2, 23) as the delay elements 17, 19, 21 on the transmission side.
It is delayed by delay elements 161, 163, 165 having τ3) and is provided to distributors 155, 157, 159, respectively.

The respective distribution outputs from the distributors 153 to 159 are frequency-converted by the frequency converters 167 to 181 using the sin and cos components of the local signal from the local signal generator 69, and the correlator 1 is used.
83-197.

The outputs of the correlators 183 to 197 are not delayed and delayed by τ1 and τ2τ3, respectively, and are multiplied by multipliers 199 to 209 for I component (in-phase signal) and Q component (quadrature signal), respectively. The multiplication outputs are added by the adders 211 to 215, and the data demodulation circuit 217 is added.
Data is demodulated at 221 to 221 and converted to a serial signal by a P / S conversion circuit (parallel-serial conversion circuit) 223 to be data.

As described above, in the conventional spread spectrum communication system, signals can be multiplexed by distinguishing the signals by the delay time, and as a result, high speed transmission can be achieved without widening the bandwidth. There is.

[0020]

However, in the conventional spread spectrum communication system, the delay time is delayed by different amounts of delay (.tau.1, .tau.2, .tau.3) for each data, and the receiver side is used to demodulate it. In this case, a delay element, a distributor, a frequency converter, a correlator, a multiplier, an adder, a data demodulation circuit, etc. are required according to the number of multiplexing, and the circuit scale increases as the number of multiplexing increases. There was a point.

The present invention has been made to solve the above problems, and provides a data demodulation method and a spread spectrum communication system which can reduce the circuit scale of a spread spectrum communication system adopting a delay multiplex system. The purpose is to provide.

[0022]

According to a data demodulating method of a first aspect of the present invention, a transmission spreading code processing signal based on a spreading code and a plurality of data processed by the spreading code for the transmission spreading code processing signal. Receiving a transmission signal including a plurality of transmission delay data processing signals obtained by delaying each of the plurality of data processing signals based on the reference delay time by a continuous natural number times, and processing the transmission signal, Generating a first spread code processed signal based on the transmission spread code processed signal and a plurality of first delay data processed signals based on the plurality of transmission delay data processed signals, and a time equal to a reference delay time Then, a plurality of second spread code processed signals obtained by delaying the first spread code processed signal and a plurality of second spread code processed signals delayed at the same time as the reference delay time. Delay Generating a data processing signal, a signal sequence consisting of a first spread code processed signal and a plurality of first delayed data processed signals, a second spread code processed signal and a plurality of second delayed data processed Multiplying a signal sequence of signals on the same time axis to generate a plurality of multiplication signals; a second spreading code processing signal and a first delay data processing signal among the plurality of multiplication signals A step of generating a multiplied signal as a reference demodulated data, the reference demodulated data, and a reference delay time or a delayed delayed multiplication signal from the reference multiplied signal And repeatedly performing the operation of outputting the demodulated data as the updated reference.

According to a second aspect of the data demodulation method of the present invention, a transmission spread code processed signal based on a spread code and a plurality of data processes based on a plurality of data processed by the spread code on the transmission spread code processed signal. Receiving a transmission signal including a plurality of transmission delay data processing signals obtained by delaying each of the signals by a continuous natural number times the reference delay time; processing the transmission signals to form a transmission spread code processing signal. A plurality of first spread code processed signals based on the plurality, first delay data processed signals based on the plurality of transmission delay data processed signals, a plurality of second spread code processed signals based on the spread code processed signals, Generating a plurality of second delayed data processed signals based on the delayed data processed signals, and a third spread code processed signal delayed for the same time as a reference delay time. And diffusing code processing signal, with reference made the delay time and the same time, a plurality of third delay data processing signal obtained by delaying a plurality of first delayed data processed signal,
A fourth spread code processed signal obtained by delaying the second spread code processed signal at the same time as the reference delay time, and a plurality of second delay data processes at the same time as the reference delay time. A step of generating a plurality of fourth delayed data processing signals obtained by delaying the signal; a signal sequence including a first spread code processed signal and a plurality of first delayed data processed signals;
The signal sequence consisting of the third spread code processed signal and the plurality of third delayed data processed signals is multiplied on the same time axis to generate a plurality of first multiplied signals, and a second spread code processing A signal sequence consisting of a signal and a plurality of second delayed data processed signals and a signal sequence composed of a fourth spread code processed signal and a plurality of fourth delayed data processed signals are multiplied on the same time axis, A step of generating a plurality of second multiplication signals; a step of adding a plurality of first multiplication signals and a plurality of second multiplication signals to generate a plurality of addition signals; A step of generating an addition signal based on the third and fourth spread code processed signals as reference demodulation data, reference demodulation data, and a reference delay from the addition signal on which the reference demodulation data is based. Time, delayed addition signal Multiplied, repeating the operation for outputting the demodulated data as the updated reference and a step.

In a spread spectrum communication system according to claim 3 of the present invention, there is provided a transmitting means for transmitting a transmission signal and a receiving means for receiving the transmission signal, and the transmitting means comprises a data generating means for generating data and a data. To parallel signals, a spreading code generating means for generating a spreading code, and a transmission side multiplying means for multiplying the spreading code and a plurality of parallel signals to generate a plurality of spreading data. , Transmitting side local signal generating means for generating a transmitting side local signal, first modulating means for modulating the transmitting side local signal with a plurality of spread data and generating a plurality of modulated spread data, and transmitting with a spreading code Second modulation means for modulating the side local signal to generate a modulation spread code, and a delay time that serves as a reference for each of a plurality of modulation spread data for the modulation spread code. Delays a natural number multiple consecutive, the transmitting side delay means for generating a plurality of delayed modulated spread data,
And a transmission signal output means for multiplexing a plurality of delay modulation spread data and a modulation spread code and transmitting as a transmission signal, wherein the receiving means divides a signal based on the transmission signal into two and generates two distribution signals. Distributing means for delaying one of the distributed signals at the same time as a reference delay time, receiving side local signal generating means for generating a receiving side local signal, and one of the delayed distributed signals. And the receiving side local signal are multiplied to form a baseband signal, the signal is correlated with a spread code to generate a first correlation signal, the other of the distributed signals is multiplied with the receiving side local signal, and A reception that generates a pre-demodulation data by multiplying the first correlation signal and the second correlation signal by a correlating unit that takes a band signal, correlates the signal with a spread code, and generates a second correlation signal Side multiplication hand And demodulation means for demodulating the data based on the pre-demodulation data, the demodulation means being based on the spread code and using the pre-demodulation data based on the first correlation signal not based on the data as a reference. The demodulation data that is generated as data and is the reference, and the delay time that is the reference from the demodulation data that is the basis of the reference demodulation data,
The operation of multiplying the delayed pre-demodulation data and outputting it as the updated reference demodulation data is repeated.

In a spread spectrum communication system according to claim 4 of the present invention, there is provided a transmitting means for transmitting a transmission signal and a receiving means for receiving the transmission signal, and the transmitting means comprises a data generating means for generating data and a data. To parallel signals, a spreading code generating means for generating a spreading code, and a transmission side multiplying means for multiplying the spreading code and a plurality of parallel signals to generate a plurality of spreading data. , A transmission-side delay unit that delays each of a plurality of spread data that is a baseband signal by a continuous natural number times the reference delay time with respect to the spread code, and generates a plurality of delay spread data. , A plurality of delay spread data and a spread code, and a combining means for generating a combined signal, a transmitting side local signal generating means for generating a transmitting side local signal, and a combining signal. And a transmission signal output means for modulating the transmission side local signal and transmitting it as a transmission signal, wherein the reception means includes a reception side local signal generation means for generating a reception side local signal, and a signal based on the transmission signal and a reception side. A frequency conversion unit that multiplies a local signal to generate a baseband signal, a distribution unit that divides the baseband signal into two, and a distribution signal, and one of the distribution signals as a reference delay time. At the same time as, one of the delayed receiving side delay means and the delayed distribution signal is correlated with a spread code to generate a delayed correlation signal, and the other distributed signal is correlated with a spread code to obtain a correlation signal. Correlation means that occur,
The reception-side multiplying unit that multiplies the delayed correlation signal and the correlation signal to generate pre-demodulation data, and the demodulation unit that demodulates the data based on the pre-demodulation data, the demodulation unit is based on the spread code The pre-demodulation data based on the delayed correlation signal that is not based on is generated as the reference demodulation data, and the reference demodulation data and the reference delay time from the reference pre-demodulation data of the reference demodulation data , The delayed pre-demodulation data is multiplied, and output as the updated reference demodulation data is repeated.

In a spread spectrum communication system according to claim 5 of the present invention, there is provided a transmitting means for transmitting a transmission signal and a receiving means for receiving the transmission signal, and the transmitting means comprises a data generating means for generating data and a data. To parallel signals, a spreading code generating means for generating a spreading code, and a transmission side multiplying means for multiplying the spreading code and a plurality of parallel signals to generate a plurality of spreading data. , Transmitting side local signal generating means for generating a transmitting side local signal, first modulating means for modulating the transmitting side local signal with a plurality of spread data and generating a plurality of modulated spread data, and transmitting with a spreading code Second modulation means for modulating the side local signal to generate a modulation spread code, and each of the plurality of modulation spread data for the modulation spread code, with a delay time as a reference. Continuous delayed by a natural number multiple, the transmitting side delay means for generating a plurality of delayed modulated spread data, a plurality of delay modulation and spreading data and modulation spreading code multiplexes,
The receiving means includes a transmitting signal output means for transmitting as a transmitting signal, and the receiving means divides a signal based on the transmitting signal into two and generates two initial distribution signals; and one of the initial distribution signals as a reference. The receiving side delay means for delaying at the same time as the delay time, the one of the delayed initial distribution signals, and the first distribution means for generating the first distribution signal, and the initial distribution signal Second distribution means for distributing the other to two and generating a second distribution signal, reception side local signal generation means for generating a reception side local signal, one of the first distribution signals and reception side local The cos component of the signal is multiplied to form a pseudo baseband signal, the signal is correlated with a spreading code to generate a first cos correlation signal, and the other of the first distributed signal and the sin component of the receiving side local signal Multiply the pseudo base van A signal, correlates the signal with a spreading code, the first for generating a first sin correlation signal
Of the second distribution signal and the cos component of the receiving side local signal are multiplied to obtain a pseudo baseband signal, and the signal is correlated with a spread code to generate a second cos correlation signal. , The other of the second distributed signals and the sin component of the receiving side local signal are multiplied to form a pseudo baseband signal, and the signal is correlated with a spread code to obtain the second sin signal.
The second correlating means for generating the correlation signal is multiplied by the first cos correlation signal and the second cos correlation signal to generate the first multiplication signal, and the first sin correlation signal and the second sin correlation signal are generated. On the basis of the pre-demodulation data, the reception-side multiplication means for multiplying the correlation signal and the second multiplication signal, the addition means for adding the first and second multiplication signals to generate the pre-demodulation data, and the pre-demodulation data. Demodulation means for demodulating data, wherein the demodulation means is based on a spreading code and is based on a first cos correlation signal that is not based on data and a first sin that is not based on the data based on the spreading code.
The pre-demodulation data based on the correlation signal is generated as the reference demodulation data, and the reference demodulation data and the pre-demodulation data that is the basis of the reference demodulation data are delayed by the reference delay time. The operation of multiplying the pre-demodulation data and outputting it as the updated reference demodulation data is repeated.

In a spread spectrum communication system according to claim 6 of the present invention, there is provided a transmitting means for transmitting a transmission signal and a receiving means for receiving the transmission signal, and the transmitting means comprises a data generating means for generating data and a data. To parallel signals, a spreading code generating means for generating a spreading code, and a transmission side multiplying means for multiplying the spreading code and a plurality of parallel signals to generate a plurality of spreading data. , A transmission-side delay unit that delays each of a plurality of spread data that is a baseband signal by a continuous natural number times the reference delay time with respect to the spread code, and generates a plurality of delay spread data. , A plurality of delay spread data and the spread code, and a combining means for generating a combined signal and a transmitting side local signal generating means for generating a transmitting side local signal, A transmission signal output means for modulating a transmission side local signal with a signal and transmitting it as a transmission signal, and the reception means divides the signal based on the transmission signal into two and generates two initial distribution signals. A receiving side local signal generating means for generating a receiving side local signal, and cos of one of the initial distribution signal and the receiving side local signal.
The first frequency conversion unit that multiplies the component and outputs the first signal of the pseudo baseband, the other of the initial distribution signal and the sin component of the reception side local signal are multiplied, and the second signal of the pseudo baseband is obtained. The second frequency converting means for outputting, the first dividing means for dividing the first signal of the pseudo baseband into two, and generating the first divided signal, and the second signal for the pseudo baseband are divided into two. Second distribution means for generating a second distribution signal, and first receiving-side delay means for delaying one of the first distribution signals for the same time as the reference delay time, The second receiving-side delay means for delaying one of the second distributed signals for the same time as the reference delay time and one of the delayed first distributed signals are correlated with the spread code to obtain the first Generate a delayed correlation signal and correlate the other of the first distribution signals with a spreading code. , The first correlation means for generating the first correlation signal and one of the delayed second distribution signals are correlated with a spread code to generate a second delayed correlation signal, and the other of the second distribution signals Is correlated with a spread code to generate a second correlation signal, the second correlation means is multiplied by the first delayed correlation signal and the first correlation signal to generate a first multiplication signal, The pre-demodulation data is obtained by adding the reception-side multiplying unit that multiplies the second delayed correlation signal and the second correlation signal to generate the second multiplication signal, and the first multiplication signal and the second multiplication signal. And an demodulation means for demodulating the data based on the pre-demodulation data, the demodulation means based on the spread code,
Data before demodulation based on a first delayed correlation signal that is not based on data and a second delayed correlation signal that is not based on data based on a spread code is generated as reference demodulation data, and is used as the reference demodulation. The data and the delay time that is the reference from the pre-demodulation data that is the basis of the demodulation data that is the reference,
The operation of multiplying the delayed pre-demodulation data and outputting it as the updated reference demodulation data is repeated.

The spread spectrum communication system according to claim 7 of the present invention is the spread spectrum communication system according to any one of claims 3 to 6, wherein the signal is based on the transmission signal and is the last transmission signal having the longest delay time. And a signal based on the first transmission signal, which follows the signal based on the last transmission signal having the longest delay time, is different from the reference delay time.

In a spread spectrum communication system according to claim 8 of the present invention, in the spread spectrum communication system according to any one of claims 3 to 6, the preamble portion of the data packet is not multiplexed, Multiplex the part that contains information data.

In a spread spectrum communication system according to claim 9 of the present invention, in the spread spectrum communication system according to any one of claims 3 to 8, the demodulation means is one of pre-demodulation data having a time spread. A filter for extracting only pre-demodulation data in a predetermined time range, an integrating means for integrating the pre-demodulation data in the predetermined time range, and a timing earlier than a signal output from a non-delayed path or demodulation pre-demodulation data And a control means for controlling the filter and the integration means, using the signal output by the above as a pilot signal.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A data demodulating method and a spread spectrum communication system according to the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a schematic block diagram showing a transmitter of a spread spectrum communication system according to a first embodiment of the present invention.

In FIG. 1, the transmitter of the spread spectrum communication system according to the first embodiment comprises a data generator 1, an S / P converter (serial / parallel converter) 3, multipliers 5, 7, 9 and a modulator. Units 11, 13, 15 and delay element 1
7, 19, 21, PN generator 23, modulator 25, multiplexer 27, frequency converter 29, power amplifier 31, antenna 3
3 and a local signal generator 35. Note that FIG.
The same parts as those in the above are denoted by the same reference numerals, and the description thereof will be appropriately omitted.

The data generated by the data generator 1 is S
The / P converter 3 causes the 3-bit parallel signal P1,
Converted to P2 and P3. Converted parallel signal P
1, P2, P3 are set to P by the corresponding multipliers 5-9.
It is multiplied by the same spread code from the N generator 9 and output to the modulators 11 to 15 as spread data D1, D2 and D3. The modulators 11 to 15 use the local signals from the local signal generator 35 to convert the spread data D1 to D3 to PS
It is K-modulated and output as modulated spread data M1, M2, M3.

The delay elements 17 to 21 are provided for the modulated spread data M.
1 to M3 are delayed and delay modulation spread data R1, R2, R
Output as 3. The delay time in the delay element 17 is τ, and the delay time in the delay element 19 is 2τ.
And the delay time in the delay element 21 is 3τ.
That is, the delay time in the delay elements 17 to 21 is τ
It ’s different. On the other hand, the spread code from the PN generator 23 is given to the modulator 25 as it is. The modulator 25 is
The spread code is PSK-modulated using the local signal from the local signal generator 35 and output as a modulated spread code N. The multiplexer 27 multiplexes the delay modulation spread data R1 to R3 and the modulation spread code N. The frequency conversion unit 29
Converts the output signal from the multiplexer 27 into an RF signal. The power amplifier 31 uses the RF from the frequency converter 29.
Power amplify the signal. And the amplified RF signal is
It is transmitted by the antenna 33.

Delay-modulated spread data R1, R2, R
3 is τ, 2τ, 3 for the modulation spread code N, respectively.
τ is delayed.

FIG. 2 is a schematic block diagram showing a receiver of the spread spectrum communication system according to the first embodiment of the present invention.

In FIG. 2, the receiver of the spread spectrum communication system according to the first embodiment of the present invention includes an antenna 51, a frequency converter 53, a distributor 55, and a delay element 5.
7, frequency converters 59 and 65, correlators 61 and 63,
Phase detector 67, local signal generator 69, multiplier 71
And a data demodulation unit 73.

The RF signal transmitted from the transmitter shown in FIG. 1 is received by the antenna 51. Frequency converter 53
Converts the RF signal into an IF signal. Distributor 55
Divides the IF signal into two and distributes the divided signals T1, T2.
Output as The frequency conversion unit 65 uses the distribution signal T1 and the cos component from the local signal generator 69,
Converted to baseband signal. The correlator 63 correlates the distribution signal T1 converted into the baseband signal with the spreading code used at the time of transmission and outputs it as the second correlation signal MS2.

The delay element 57 delays the distributed signal T1 and outputs it. The delay time in the delay element 57 is similar to the delay time τ of the delay element 17 of the receiver shown in FIG.

The frequency conversion section 59 has the delayed distribution signal T.
1 and co of the local signal from the local signal generator 69.
It is converted to a baseband signal using the s component. The correlator 61 correlates the delayed distribution signal T1 converted into the baseband signal with the spreading code used at the time of transmission and outputs it as the first correlation signal MS1.

The phase detector 67 detects the carrier phase offset of the signal and controls the local signal generator 69 using the control signal CS to establish carrier synchronization. The multiplier 71 uses the first correlation signal MS1
And the second correlation signal MS2 are multiplied and output as pre-demodulation data F. The data demodulation unit 73 demodulates the data using the pre-demodulation data F. Next, the manner of demodulation in the data demodulation unit 73 will be described in detail.

FIG. 3 is a diagram for explaining the data demodulation in the data demodulation section 73 of FIG. 2 in detail.

FIG. 3 (a) shows the waveform of the second correlation signal MS2 output from the correlator 63 of FIG.
The signal A is a signal based on the modulation spread code N of FIG.
This is the signal that is not delayed at the transmitter. Signal B
Is delayed with respect to the signal A, corresponds to the delay modulation spread data R1 in FIG. 1, and is a multiplexed signal component.
The signal C is delayed from the signal B by τ and is a multiplexed signal component corresponding to the delay modulation spread data R2 in FIG.
The signal D is delayed by τ from the signal C, and is a multiplexed signal component corresponding to the delay modulation spread data R3 in FIG.
The time τ is similar to the delay time τ of the delay element 17 in FIG.

FIG. 3B shows the waveform of the first correlation signal MS1 output from the correlator 61 of FIG.
The first correlation signal is delayed by τ with respect to the second correlation signal shown in (a). The signal E is the modulation spread code N of FIG.
Is a signal that is not delayed by the transmitter. The signal F is delayed by τ with respect to the signal E.
Is a multiplexed signal component corresponding to the delay modulation spread data R1. The signal G is delayed by τ with respect to the signal F, and is a multiplexed signal component corresponding to the delay modulation spread data R2 in FIG. The signal H is delayed by τ with respect to the signal G,
It is a multiplexed signal component corresponding to the delay modulation spread data R3 in FIG.

FIG. 3C shows the waveform of the pre-demodulation data F of FIG. That is, the pre-demodulation data F in (c)
Is a product of the second correlation signal MS2 shown in (a) and the first correlation signal MS1 shown in (b). Signal B
And the information of the signal E is “1”, and when multiplied, the signal I
And the information is “1”. Information of signal C is "-1"
Since the information of the signal F is “1”, the signal J obtained by multiplying them is the information of “−1”. The information of the signal D and the signal G is “−1”, and the information of the signal K obtained by multiplying them is “1”. As for the signal A and the signal H, there is no signal to be multiplied, so no signal appears in (c). The signal J is delayed from the signal I by τ. The signal K lags the signal J by τ. In summary, the information of the signal I, the signal J, and the signal K is “1”, “−1”, and “1”, respectively.

FIG. 4 is a block diagram showing details of the data demodulation unit 53 of FIG. In FIG. 4, the data demodulation unit includes a multiplier 81 and a selection delay unit 83.

Here, the signal I of FIG. 3 (c) is a signal E that is not modulated with data (modulated with only a spreading code),
The demodulated data of the signal I is “1” because it is the multiplication result with the signal B modulated with the data (modulated with the data and the spread code). That is, the information of the signal obtained by multiplying the signal not modulated with the data and the signal modulated with the data becomes the demodulated data as it is.

The demodulated data "1" of the signal I is delayed by τ by the selection delay unit 83 and output to the multiplier 81. Then, the multiplier 81 multiplies the information “−1” of the signal J by the demodulation data “1” based on the signal I from the selection delay unit 83, and outputs “−1” as the demodulation data of the signal J. To do.

Next, the demodulated data “−1” of the signal J is delayed by τ by the selection delay unit 83 and output to the multiplier 81. Then, the multiplier 81 determines that the amplitude of the signal K is “1”.
And the demodulation data "-1" based on the signal J from the selection delay unit 83 are multiplied, and the demodulation data "-1" of the signal K is output. To summarize the above, the signals I, J and K in FIG.
Demodulated data of "1", "-1" and "-", respectively.
1 ".

As described above, in the data demodulation in the data demodulation section of FIG. 4, except for the first signal (signal I), the immediately preceding signal (signal I for signal J and signal I for signal K) is used. Data is demodulated by multiplying the demodulated data of J) by the signal to be demodulated (signal J, signal K). Regarding the first signal (signal I), the information of the first signal (signal I) is the demodulated data as it is.

FIG. 5 is a flow chart showing the process of demodulation in the data demodulation section shown in FIG.

In FIG. 5, the first pre-demodulation data F is detected in step S1. This pre-demodulation data F is shown in FIG.
It is the pre-demodulation data F output from the multiplier 71. The first pre-demodulation data F is the signal I in FIG.

In step S3, the first pre-demodulation data F is demodulated. That is, as shown in the description of FIG. 4, the information of the first pre-demodulation data F becomes the demodulation data of the first pre-demodulation data F as it is.

In step S5, the demodulation data immediately before the pre-demodulation data to be demodulated is multiplied by the pre-demodulation data to be demodulated. When it is desired to demodulate the pre-demodulation data subsequent to the first pre-demodulation data F, the demodulation data of the first pre-demodulation data F and the pre-demodulation data to be demodulated are multiplied. The result is the demodulation data of the pre-demodulation data that follows the first pre-demodulation data.

In S7, when k becomes n, demodulation of one set of data multiplexed by the transmitter of FIG. 1 is completed. Note that n is the number of multiplexes in the transmitter. That is, in FIG. 1, n = 3.

In S7, the demodulation data of the pre-demodulation data to be demodulated, which is the result of multiplying the previous demodulation data by the pre-demodulation data to be demodulated, until k becomes n,
In step S5, the demodulated data fed back is multiplied by the pre-demodulation data that follows the pre-demodulation data that is the source of the fed-back demodulation data, and the pre-demodulation data that is the source of the fed-back demodulation data is multiplied. Is output as demodulation data of the pre-demodulation data that comes after.

Such an operation is repeated until k becomes n (the number of multiplexes) in step S7. When this operation ends and the demodulation of one set of multiplexed data ends, the demodulation operation of the next transmitted set of multiplexed data is similarly performed.

As described above, the transmitter of the spread spectrum communication system according to the first embodiment delays a plurality of modulated spread data M1 to M3 at the same time interval (τ) and multiplexes them. Send a signal.

The receiver of the spread spectrum communication system according to the first embodiment uses the demodulation data demodulated using the pre-demodulation data based on the delay modulation spread data R1 having the shortest delay time as a reference. Of the demodulated data and the pre-demodulation data that is delayed by time τ from the pre-demodulation data that is the basis of the reference demodulation data, and outputs the multiplied signal as the updated reference demodulation data. Is repeating.

Therefore, in the receiver, it suffices to prepare a path that is not delayed and a path that is delayed by the time τ, and the circuit scale in the receiver can be significantly reduced. In other words, for demodulation, it is not necessary to provide all the circuits that had to be provided according to the number of multiplexed data to be transmitted, and the circuit scale becomes smaller. This enables downsizing, low power consumption, and low price of the spread spectrum communication system. Particularly, in the receiver, since the circuit scale related to demodulation is constant regardless of the number of multiplexing, such an effect becomes more remarkable as the number of multiplexing data increases.

It should be noted that, so far, a case has been described in which the three pieces of modulated spread data M1 to M3 are delayed and multiplexed, but the number of the multiplexes may be any number. Also in this case, the same effect as described above can be obtained.

Further, in the first embodiment, if a bit error occurs in the middle, there is a fear that the subsequent bits will be erroneous. However, for a line with such an extremely high error rate, the one shown in FIG. 14 is used. As shown in FIG.
The delay times of the delay elements 17 to 21 in
By setting τ, τ2 = τ, and τ3 = τ, an error of only 1 bit occurs, and compatibility can be maintained.

That is, as a receiver for the transmitter shown in FIG. 1 according to the first embodiment, the receiver shown in FIG.
Four receivers can be used.

Further, when the number of multiplexes is 6 (when the delay modulation spread data in FIG. 1 is 6), the configuration is such that three are shared, so that the circuit scale is slightly larger. However, it is possible to suppress the bit error rate.

(Second Embodiment) FIG. 6 is a schematic block diagram showing a transmitter of a spread spectrum communication system according to a second embodiment of the present invention.

In FIG. 6, the transmitter according to the second embodiment comprises a data generator 1, an S / P converter (serial / parallel converter) 3, multipliers 5, 7, 9 and delay elements 17, 1.
9, 21, PN generator 23, multiplexer 27, modulator 91,
The frequency converter 29, the power amplifier 31, the antenna 33, and the local signal generator 35 are included. The same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

In FIG. 6, the data generated by the data generator 1 is serial-parallel converted by the S / P converter 3 to become 3-bit parallel signals P1, P2, P3. The parallel signals P1 to P3 correspond to the corresponding multipliers 5 to 9
By the spreading code from the PN generator 23,
The spread data D1, D2 and D3 are output.

The spread data D1 to D3 are delayed by different delay times by the corresponding delay elements 17 to 21 and output as delayed spread data Y1, Y2, Y3. The delay time in the delay element 17 is τ,
The delay time in the delay element 19 is 2τ, and the delay time in the delay element 21 is 3τ. That is, the spread data D1 to D3 are delayed by the same time interval τ.

The multiplexer 27 outputs the delay spread data Y1 to Y3.
And the spread codes from the PN generator 23 are combined and output as a combined signal A. The modulator 91 modulates the combined signal A using the local signal from the local signal generator 35, and outputs the modulated signal to the frequency conversion unit 29. The frequency conversion unit 29 converts the modulated signal from the modulator 91 into an RF signal. Then, the power amplifying unit 31 uses the RF
Power amplify the signal. The antenna 33 transmits the power-amplified RF signal.

FIG. 7 is a schematic block diagram showing a receiver of a spread spectrum communication system according to the second embodiment of the present invention.

FIG. 7 shows a receiver of the spread spectrum communication system according to the second embodiment, which includes an antenna 51, frequency converters 53 and 101, a local signal generator 69, a phase detector 67, a distributor 55, and a delay element. 57, correlator 6
1, 63, a multiplier 71 and a data demodulation unit 73.
The same parts as those in FIG. 2 are designated by the same reference numerals and the description thereof will be appropriately omitted.

The antenna 51 receives the RF signal transmitted from the transmitter shown in FIG. The frequency conversion unit 53 converts the RF signal into an IF signal. The frequency conversion unit 101
The F signal is converted into the baseband signal BB by using the cos component of the local signal from the local signal generator 69.

The distributor 55 outputs the baseband signal BB to 2
And outputs distribution signals T1 and T2. The correlator 63 correlates the distribution signal T2 with the spreading code on the reception side and outputs the correlation signal MS. The delay element 57 delays the divided signal T1 with a delay time τ and outputs the delayed signal. In addition,
This delay time τ is similar to the delay time τ of the delay element 17 in FIG.

The correlator 61 receives the delayed distribution signal T
1 is correlated with the spread code on the receiving side to obtain the delayed correlation signal D
Output S. The multiplier 71 multiplies the correlation signal MS and the delayed correlation signal DS and outputs the pre-demodulation data F. The data demodulation unit 73 demodulates the data based on the pre-demodulation data F. The data demodulation method in the data demodulation unit 73 is
This is similar to the data demodulation unit 73 in FIG.

As described above, the transmitter of the spread spectrum communication system according to the second embodiment uses D1 of the spread data.
~ D3 are delayed by the same time interval τ, and the multiplexed transmission signals are transmitted. Then, the receiver of the spread spectrum communication system according to the second exemplary embodiment uses the delay spread data Y
Based on the demodulated data demodulated using the pre-demodulation data F based on 1, the reference demodulation data and the time τ from the pre-demodulation data that is the basis of the reference demodulation data
The operation of multiplying the delayed pre-demodulation data and outputting the multiplied signal as the updated reference demodulation data is repeated.

As a result, the spread spectrum communication system according to the second embodiment of the present invention has the same effect as the spread spectrum communication system according to the first embodiment. Furthermore, in the transmitter of FIG.
Signals delayed by 1 (spread data D1 to D3)
Is a baseband signal, it is possible to reduce the number of modulators in the transmitter and the number of frequency converters in the receiver, which are relatively large in circuit scale.

(Third Embodiment) FIG. 8 is a schematic block diagram showing a receiver of a spread spectrum communication system according to a third embodiment of the present invention.

In FIG. 8, the receiver according to the third embodiment has an antenna 51 and frequency conversion units 53, 117, 11
9, 121, 123, delay element 57, distributors 111, 1
13, 115, local signal generator 69, correlator 1
25, 127, 129, 131, multipliers 133, 13
5, an adder 137 and a data demodulation unit 73 are included. The transmitter of the spread spectrum communication system according to the third embodiment is the same as the transmitter of the spread spectrum communication system of FIG.

The antenna 51 receives the RF signal transmitted from the transmitter shown in FIG. The frequency conversion unit 53
The F signal is converted into an IF signal (intermediate frequency signal). The distributor 111 distributes the IF signal into two, and the initial distribution signal T
1 and T2 are output.

The distributor 113 distributes the initial distribution signal T2 into two and outputs the second distribution signals TA1 and TA2.
The frequency conversion unit 117 frequency-converts the second distributed signal TA1 by using the sin component of the local signal from the local signal generator 69 to form a quadrature signal (Q signal). Then, the Q signal is correlated with the spread code of the transmitter by the correlator 125 to obtain the second sin correlation signal SI2.
Is output.

The frequency conversion section 119 uses the second distribution signal T
A2 is frequency-converted using the cos component of the local signal from the local signal generator 69, and an in-phase signal (I signal) is output. The correlator 127 is the frequency conversion unit 1
Correlate the I signal from 19 with the spreading code of the receiver,
The second cos correlation signal CO2 is output.

The delay element 57 delays and outputs the initial distribution signal T1. The delay time is the same as the delay time τ in the delay element 17 of FIG.

The distributor 115 distributes the delayed initial distribution signal T1 into two, and outputs first distribution signals TB1 and TB2.

The frequency conversion section 121 uses the first distribution signal T
B1 is frequency-converted using the sin component of the local signal from the local signal generator 69, and a quadrature signal (Q signal) is output. The correlator 129 is the frequency conversion unit 1
Correlate the Q signal from 21 with the spreading code of the transmitter,
The first sin correlation signal SI1 is output.

The frequency converter 123 receives the first distribution signal T
B2 is frequency-converted using the cos component of the local signal from the local signal generator 69, and an in-phase signal (I signal) is output. The correlator 131 includes the frequency conversion unit 1
I signal from 23 is correlated with the spread code of the transmitter,
Output a first cos correlation signal.

The multiplier 133 receives the second sin correlation signal S
I2 is multiplied by the first sin correlation signal SI1 to output the second multiplication signal MM2.

The multiplier 135 outputs the second cos correlation signal C
O2 is multiplied by the first cos correlation signal CO1 to output the first multiplication signal MM1.

The adder 137 adds the first multiplication signal MM1 and the second multiplication signal MM2 and outputs pre-demodulation data F. The data demodulation unit 73 demodulates the data based on the pre-demodulation data F. The data demodulation unit 73 is shown in FIG.
This is the same as the data demodulation unit 73 of. That is, the data demodulation method in the data demodulation unit 73 is the same as the data demodulation method in the data demodulation unit 73 in FIG.

As described above, the transmitter of the spread spectrum communication system according to the third embodiment of the present invention delays a plurality of modulated spread data M1 to M3 at the same time interval τ and transmits a multiplexed transmission signal. To do. Then, the receiver of the spread spectrum communication system according to the third exemplary embodiment of the present invention uses the demodulation data demodulated using the pre-demodulation data F based on the delay modulation spread data R1 as a reference, and the reference demodulation data. And the pre-demodulation data that is later by τ than the pre-demodulation data F that is the basis of the demodulation data that serves as the reference, and outputs the multiplied signal as updated reference demodulation data. .

As a result, the spread spectrum communication system according to the third embodiment of the present invention has the same effects as the spread spectrum communication system according to the first embodiment.

Further, in this embodiment, the local signal of the local signal generator 69 is obtained by using a phase detector or the like.
It is not necessary to make it the same as that on the transmitting side, and the circuit scale of the spread spectrum communication system can be reduced. Furthermore, the synchronization time for phase synchronization is unnecessary, and the initial operation becomes faster.

(Fourth Embodiment) FIG. 9 is a schematic block diagram showing a receiver of a spread spectrum communication system according to a fourth embodiment of the present invention.

In FIG. 9, the receiver of the spread spectrum communication system according to the fourth embodiment of the present invention comprises an antenna 51, frequency converters 53, 141 and 143, and a distributor 11.
1, 113, 115, local signal generator 69, delay elements 145, 147, correlators 125, 127, 12
9, 131, multipliers 133, 135, an adder 137, and a data demodulation unit 73. The transmitter of the spread spectrum communication system according to the fourth exemplary embodiment of the present invention is
It is similar to the transmitter of FIG.

In FIG. 9, the antenna 51 receives the RF signal transmitted from the transmitter of FIG. The frequency conversion unit 53 converts the received RF signal into an IF signal (intermediate frequency signal). The distributor 111 distributes the IF signal into two and outputs initial distribution signals T1 and T2.

The frequency conversion section 141 uses the initial distribution signal T1.
Of the local signal from the local signal generator 69.
Frequency conversion is performed using the s component to convert into a pseudo baseband in-phase signal (I signal), and the first signal S1 is output.

The distributor 113 divides the first signal S1 into two and outputs the first distribution signals TA1 and TA2.

The correlator 125 receives the first distribution signal TA.
1 is correlated with the spread code of the transmitter, and the first correlation signal MS1 is output.

The delay element 145 has the first distribution signal TA2.
Delay. The delay time is the same as the delay element 1 of FIG.
It is similar to the delay time τ in 7.

The correlator 127 correlates the delayed first distribution signal TA2 with the spreading code of the transmitter to obtain the first distribution signal TA2.
And outputs the delayed correlation signal DS1.

The multiplier 133 multiplies the first correlation signal MS1 and the first delayed correlation signal DS1 to obtain the first multiplication signal M.
Output M1.

The frequency conversion section 143 has the initial distribution signal T2.
Si of the local signal from the local signal generator 69.
Frequency conversion is performed using the n component to convert into a pseudo baseband quadrature signal (Q signal), which is output as the second signal S2.

The distributor 115 divides the second signal S2 into two and outputs the second distribution signals TB1 and TB2.

The correlator 129 outputs the second distribution signal TB.
1 is correlated with the spreading code of the transmitter, and the second correlation signal MS2 is output.

The delay element 147 has the second distribution signal TB2.
Delay. The delay time is the same as the delay element 1 of FIG.
It is similar to the delay time τ in 7.

The correlator 131 correlates the delayed second distribution signal TB2 with the spreading code of the transmitter to generate the second correlation signal TB2.
And outputs the delayed correlation signal DS2.

The multiplier 135 multiplies the second correlation signal MS2 and the second delayed correlation signal DS2 to obtain the second multiplication signal M.
Output M2.

The adder 137 adds the first multiplication signal MM1 and the second multiplication signal MM2 and outputs pre-demodulation data F. The data demodulation unit 73 demodulates the data based on the pre-demodulation data F.

The data demodulation unit 73 is similar to the data demodulation unit 73 of FIG. That is, the data demodulation method in the data demodulation unit 73 is the same as the data demodulation method in the data demodulation unit 73 in FIG.

As described above, the transmitter of the spread spectrum communication system according to the fourth embodiment of the present invention delays the spread data D1 to D3 by the same time interval τ and transmits the multiplexed transmission signal. Then, the receiver of the spread spectrum communication system according to the fourth exemplary embodiment of the present invention uses the demodulated data demodulated using the pre-demodulation data F having the shortest delay time as a reference, and the reference demodulated data, and The operation of multiplying the pre-demodulation data following the pre-demodulation data that is the basis of the reference demodulation data and outputting the signal as updated reference demodulation data is repeated.

As a result, the spread spectrum communication system according to the fourth embodiment of the present invention has the same effect as the spread spectrum communication system according to the second embodiment of the present invention.

Further, in this embodiment, the local signal of the local signal generator 69 is obtained by using a phase detector or the like.
It is not necessary to make it the same as that on the transmitting side, and the circuit scale of the spread spectrum communication system can be reduced. Furthermore, the synchronization time for phase synchronization is unnecessary, and the initial operation becomes faster.

(Fifth Embodiment) The transmitter and the receiver of the spread spectrum communication system according to the fifth embodiment are the spread spectrum communication systems according to any one of the spread spectrum communication systems according to the first to fourth embodiments. The configuration is the same as that of the transmitter and the receiver of the communication system. In the description of this embodiment, the transmitter and the receiver described in FIGS. 1 and 2 are used.

Although three data are multiplexed in FIG. 1, in the present embodiment, four data are multiplexed when the wireless system is spread by 10 chips. In this case, the multiplier,
One more modulator and one more delay element will be added.

FIG. 10 shows the correlator 6 of the receiver shown in FIG.
It is a figure which shows the waveform of the general output signal from 1, 63 and the multiplier 71.

FIG. 10 (a) shows the waveform of the second correlation signal MS2 from the correlator 63 of FIG. Signal A
₁ , signal B ₁ , signal C ₁ , signal D ₁ , and signal E
₁ and the signal A ₂ , the signal B ₂ , the signal C ₂ , the signal D ₂ and the signal E ₂ are each a set of multiplexed data. Here, the respective signals are separated by time τ. The time τ is similar to the delay time τ of the delay element 17 in FIG. Also, τ is set to 2 chips.

FIG. 10 (b) shows the waveform of the first correlation signal MS1 from the correlator 61 of FIG. The first correlation signal MS1 is the second correlation signal MS shown in (a).
2 is delayed by τ. For time τ,
It is the same as the time τ described in (a). The signal A ₁₁ , the signal B ₁₁ , the signal C ₁₁ , the signal D ₁₁ , the signal E ₁₁ , the signal A ₂₂ , the signal B ₂₂ , the signal C ₂₂ , the signal D _22, and the signal E ₂₂ are signal A ₁ and signal B ₁ , respectively. , Signal C ₁ , signal D ₁ , signal E
_{1 corresponds} to signal A ₂ , signal B ₂ , signal C ₂ , signal D ₂ and signal E ₂ .

FIG. 10 (c) shows the waveform of the pre-demodulation data F from the multiplier 71 of FIG. Signal F shown in (c)
N is obtained by multiplying the signals A _{1 to} E ₂ shown in (a) and the signals A _{11 to} E ₂₂ shown in (b) by the corresponding signals.

As shown in FIGS. 10A to 10C, the signals A ₂ and E ₁₁ have the same timing. For this reason, it becomes impossible to determine the reference signal used during demodulation, that is, the signal A ₂ (a signal that is not data-modulated in the transmitter and is based on only the spreading code).

FIG. 11 shows the case where the spread spectrum communication system according to the fifth embodiment of the present invention is used.
FIG. 3 is a diagram showing waveforms of output signals from correlators 61 and 63 and a multiplier 71 of FIG. 2.

FIG. 11 (a) shows the waveform of the second correlation signal MS2 from the correlator 63 of FIG. Signal A
₁ to the signal E ₂ , the signal A shown in FIG.
₁ to the same as the signal E ₂ . However, in FIG. 11A, the time difference between the signal E ₁ and the signal A ₂ is different from the time difference τ of each of the other signals.

FIG. 11 (b) shows the waveform of the first correlation signal MS1 from the correlator 61 of FIG. Signal A
₁₁ to signal E ₂₂ are the same as signal A ₁₁ to signal E ₂₂ in FIG. However, the time difference between the signal E ₁₁ and the signal A ₂₂ is different from the time difference τ of each of the other signals. That is, it is the same time difference as the signal E ₁ and the signal A ₂ .

FIG. 11 (c) shows the waveform of the pre-demodulation data F from the multiplier 71 of FIG. That is, the signal F
~ Signal N is signal A _{1 to} E ₂ of (a) and signal A of (b)
_{11 to} E ₂₂ are obtained by multiplying corresponding signals by each other. Here, the time difference between the signal I and the signal K is different from the time difference τ of each of the other signals.

As described above, in the fifth embodiment of the present invention, the signal (signal E ₁ and signal E ₁₁ ) having the longest delay time among the plurality of multiplexed signals and the data The time difference with the unmodulated signals (signal A ₂ , signal A ₂₂ ) based only on the spread code is made different from the time difference τ of each of the other signals.

Therefore, it is possible to easily discriminate the reference signals used at the time of demodulation, that is, the signals A ₂ and A ₂₂ (the signals that are not data-modulated in the transmitter and are based only on the spread code) and the signal K. . That is, the demodulation reference can be taken easily, the processing can be simplified, and erroneous demodulation can be prevented. Other effects are similar to those of the first to fourth embodiments.

(Sixth Embodiment) A transmitter and a receiver of a spread spectrum communication system according to a sixth embodiment of the present invention are the transmitter and the receiver of a spread spectrum communication system according to the fifth embodiment. The configuration is the same.
Further, as in the case of the fifth embodiment, the transmitter (FIG. 1) and the receiver (FIG. 2) according to the first embodiment are used in the description of the present embodiment.

In the transmitter of FIG. 1, three data are multiplexed, but in the present embodiment, four data are multiplexed.
A case where one data is multiplexed will be described. At this time, the number of multipliers, modulators and delay elements in FIG. 1 is increased by one.

In the fifth embodiment, among the multiplexed signals, the time difference between the signal having the longest delay time and the reference signal for the next demodulation is calculated as the time difference between the other signals. , The reference signal is detected during demodulation, but it may not be adopted in an actual system. For example, there is a case where a digital delay method is used and delay can be made only by an integral multiple of a chip.

Therefore, in the present embodiment, in the data non-modulation section such as the preamble section (the section used for various functions in the spread spectrum communication system) of the data string to be transmitted, the transmitter of FIG. In the above, the data format is configured so as not to be multiplexed by using the delay method. Generally, when communicating data,
Packet communication is often used. Therefore, the original data format has a portion corresponding to a preamble portion for carrier synchronization and spread code synchronization.

The above will be described in detail. FIG.
It is a figure which shows the data format in the spread spectrum communication system by the 6th Embodiment of this invention.

FIG. 12A shows a data packet. One data packet aa (one frame) includes a data non-modulation section such as a preamble section (hereinafter, simply referred to as “preamble section”) aa1 and an information data section aa2.
Consists of The preamble part aa1 is a part that is not multiplexed,
The information data part aa2 is a multiplexing part.

FIG. 12B shows a part of FIG. 12A in detail. The preamble part aa1 includes a plurality of partial preamble parts bb1. The information data part aa2 includes a plurality of data bb2. One set of data bb2 multiplexes four signals (4 waves).

FIG. 12C is based on the partial preamble part bb1 and the data bb2 shown in FIG. 12B.
Second correlation signal MS from correlator 63 in FIG.
2 is shown. Non-multiplexed part (partial preamble b
In b1), the transmitter transmits the signal modulated only with the spreading code and the signal modulated with the spreading code and the data. Therefore, as shown by cc1 in (c), the second correlation signal from the correlator 63 in FIG. 2 based on one partial preamble part bb1 is 2 signals of the signal A and the signal B.
It becomes one.

Here, the signal A is a signal which is not data-modulated and is based only on the spread code. The signal B is a signal based on a spreading code and data. By doing so, it becomes possible to identify the signal A that is not data-modulated and is based only on the spread code.

The second correlation signal MS2 from the correlator 63 of FIG. 2 based on one data bb2 is the signal A, the signal B, the signal C, the signal D, and the signal E. The signal A is the second correlation signal based on the signal modulated by only the spreading code. Signals B to E are second correlation signals based on signals modulated with spreading codes and data. That is, signals based on four data and spread codes are multiplexed.

From the part cc2 in FIG. 12C, it is not possible to identify where the signal A which is the reference for demodulation is, but c
By referring to the timing cycle of the signal A identified in the part of c1, the part of cc2 (data multiplexing part)
Also in the above, the signal A serving as a reference for demodulation can be determined.

As described above, in the sixth embodiment of the present invention, the preamble part a of the data packet aa is used.
A1 is not multiplexed, and information data aa2 is multiplexed. Therefore, it becomes possible to establish the synchronization timing of the spread code and at the same time establish the reference of the multiple wave (the signal serving as the reference of the demodulation).
Of the correlation signal MS1 and the second correlation signal MS2 of FIG.
Even at the timing as shown in (4), it becomes possible to easily determine the signal serving as the demodulation reference.

As a result, the demodulation reference can be easily taken,
It is possible to simplify the process and prevent erroneous demodulation. Other effects are similar to those of the first to fourth embodiments. The fifth embodiment and the sixth embodiment can be used at the same time.

(Seventh Embodiment) First, a method called PDI (post detection integration) for synthesizing signals dispersed by multipath in wireless communication in a room will be described.

When a multipath occurs in a wireless communication system in a room, a received signal causes delay spread,
For example, the pre-demodulation data F from the multiplier 71 in FIG. 2 also has a delay spread.

This is because a plurality of waves having different transmission paths arrive at the same time. Generally, in a spread spectrum communication system, PDI is used in order to improve the characteristics under such multipath. PDI
Is performed using, for example, a filter and an integrator (not shown) in the data demodulation unit 73 of FIGS. 2, 7, 8 and 9.

The filter extracts only the pre-demodulation data F in a predetermined time range from the pre-demodulation data F having a time spread (delay spread) due to multipath. The integrator integrates the pre-demodulation data F extracted by the filter in a predetermined time range.

In the present embodiment, in the control circuit (not shown), the signal output from the non-delayed path or the signal output at a timing faster than the pre-demodulation data F to be demodulated is used as the pilot signal and the signal in the filter is set. It controls the extraction time width (filter time window) and the integration in the integrator.

Here, the signal output from the non-delayed path is, for example, the second correlation signal MS2 output from the correlator 63 in FIG. The signal output at a timing faster than the pre-demodulation data F to be demodulated is the signal F for the signal G in FIG. 11, for example.

As described above, in the seventh embodiment of the present invention, the signal output from the path which is not delayed or the signal output at a timing faster than the pre-demodulation data to be demodulated is used as the pilot signal for the filter and the integration. Since the device can be controlled, the effect of PDI can be improved and the error rate of the wireless line can be improved.

Further, in the case of the seventh embodiment, since the demodulation path is only one system, the circuit can be simplified as compared with the conventional case where the filter and the integrator are controlled for each system.

In the conventional spread spectrum communication system of FIGS. 13 and 14, since the first signal which is not data-modulated and which is based only on the spread code is demodulated, the time is delayed for that signal. The signal that is delayed in time (multiplexed signal that comes later) may be converted by the transmission path in the meantime.

However, in the seventh embodiment of the present invention, a signal serving as a reference for demodulation (for example, in FIG. 3 (c), the signal J is the signal I and the signal K is the signal J). , Etc.) is always the signal before the time τ, the PDI can be performed correctly with less change in the transmission path as compared with the conventional spread spectrum communication system.

The transmitter and receiver of the spread spectrum communication system according to the present embodiment are the transmitter and receiver of the spread spectrum communication system of any one of the spread spectrum communication systems according to the first and fourth embodiments. A receiver can be used.

Further, the present embodiment and the fifth embodiment,
This Embodiment and 6th Embodiment, This Embodiment and 5th Embodiment
It is also possible to use the embodiment and the sixth embodiment in combination. In this case, the fifth embodiment or the sixth embodiment
The same effect as that of the embodiment is obtained.

[0151]

As described above, in the data demodulating method according to the first aspect of the present invention, each of the plurality of data processing signals is delayed at the same time interval, the multiplexed transmission signal is received, and the delay time is reduced. The demodulation data of the data that is the basis of the shortest multiplication signal is used as a reference, and the reference demodulation data and the next multiplication signal whose delay time is later than the reference multiplication signal of the reference demodulation data The operation of multiplying and outputting the signal as the updated reference demodulated data is repeated.

Therefore, in order to demodulate the data, it is not necessary to provide all the circuits that have to be provided in accordance with the number of multiplexed data, the circuit scale can be reduced, the system can be downsized, and the power consumption can be reduced. And it becomes possible to realize a low price.

Further, since the circuit scale related to data demodulation is constant regardless of the number of multiplexing, the reduction rate of the circuit scale increases as the number of multiplexing increases.

In the data demodulating method according to the second aspect of the present invention, each of the plurality of data processing signals is delayed at the same time interval, the multiplexed transmission signal is received, and the addition signal having the shortest delay time is generated. The demodulation data of the data is used as a reference, the reference demodulation data is multiplied by the next addition signal whose reference delay time is later than the reference addition signal of the reference demodulation data, and the signal is updated. The operation of outputting the demodulated data serving as the reference is repeated.

Therefore, in order to demodulate data, it is not necessary to provide all the circuits that had to be provided in accordance with the number of multiplexed data, the circuit scale can be reduced, the system can be downsized, and the power consumption can be reduced. And it becomes possible to realize a low price.

Furthermore, since the circuit scale related to data demodulation is constant regardless of the number of multiplexing, the circuit scale reduction rate increases as the number of multiplexing increases. In the spread spectrum communication system according to claim 3 of the present invention, each of the plurality of modulated spread data is delayed at the same time interval, the multiplexed transmission signal is received, and the pre-demodulation data having the shortest delay time is generated. The demodulated data of the data is used as a reference, and the reference demodulated data is multiplied by the next pre-demodulation data whose delay time is later than the reference pre-demodulation data that is the basis of the reference demodulated data, and the signal Is repeated as the updated reference demodulation data.

Therefore, because of the demodulation, it is not necessary to provide all the circuits that had to be provided according to the number of multiplexed data, the circuit scale can be reduced, the system can be downsized, the power consumption can be reduced, and the price can be reduced. Can be realized.

Further, since the circuit scale related to data demodulation is constant regardless of the number of multiplexing, the reduction rate of the circuit scale increases as the number of multiplexing increases.

In the spread spectrum communication system according to claim 4 of the present invention, each of the plurality of spread data is delayed at the same time interval, the multiplexed transmission signal is received, and the pre-demodulation data with the shortest delay time is received. With the demodulated data of the original data as a reference, the reference demodulated data is multiplied by the next pre-demodulation data having a reference delay time later than the pre-demodulation data that is the basis of the reference demodulation data, The operation of outputting the signal as the updated reference demodulated data is repeated.

Therefore, because of demodulation, it is not necessary to provide all the circuits that had to be provided according to the number of multiplexed data, the circuit scale can be reduced, and the system can be downsized, the power consumption can be reduced, and the price can be reduced. Can be realized.

Further, since the circuit scale related to data demodulation is constant regardless of the number of multiplexing, the reduction rate of the circuit scale increases as the number of multiplexing increases.

In the spread spectrum communication system according to claim 5 of the present invention, each of the plurality of modulated spread data is delayed at the same time interval, the multiplexed transmission signal is received, and the pre-demodulation data having the shortest delay time is received. Using the demodulation data of the data that is the basis of the reference as the reference, the reference demodulation data is multiplied by the next pre-demodulation data that is later than the reference pre-demodulation data that is the reference demodulation data by the reference delay time. The operation of outputting the signal as updated reference demodulated data is repeated.

Therefore, because of the demodulation, it is not necessary to provide all the circuits that had to be provided in accordance with the number of multiplexed data, the circuit scale can be reduced, the system can be downsized, the power consumption can be reduced, and the price can be reduced. Can be realized.

Further, since the circuit scale related to the data demodulation is constant regardless of the number of multiplexing, the reduction rate of the circuit scale increases as the number of multiplexing increases.

In the spread spectrum communication system according to claim 6 of the present invention, each of the plurality of spread data is delayed at the same time interval, the multiplexed transmission signal is received, and the pre-demodulation data having the shortest delay time is received. With the demodulated data of the original data as a reference, the reference demodulated data is multiplied by the next pre-demodulation data having a reference delay time later than the pre-demodulation data that is the basis of the reference demodulation data, The operation of outputting the signal as the updated reference demodulated data is repeated.

Therefore, for demodulation, it is not necessary to provide all the circuits that had to be provided according to the number of multiplexed data, the circuit scale can be reduced, and the system can be downsized.
It is possible to realize low power consumption and low price.

Further, since the circuit scale related to data demodulation is constant regardless of the number of multiplexing, the reduction rate of the circuit scale increases as the number of multiplexing increases.

In the spread spectrum communication system according to claim 7 of the present invention, the signal based on the transmission signal having the longest delay time and the signal based on the first transmission signal next thereto, that is, the signal serving as the demodulation reference. Since the time intervals of can be made different, it is possible to easily determine the signal that is the reference for demodulation. Therefore, the demodulation standard can be easily taken,
It is possible to simplify the processing and prevent erroneous demodulation.

In the spread spectrum communication system according to the eighth aspect of the present invention, the preamble portion of the data packet is not multiplexed, and the portion containing the data to be information is multiplexed. The signal that becomes Therefore, the demodulation reference can be taken easily, the processing can be simplified, and erroneous demodulation can be prevented.

In the spread spectrum communication system according to claim 9 of the present invention, the filter and the integrator are provided with the signal output from the non-delayed path or the signal output at a timing faster than the demodulated data before demodulation as the pilot signal. Since it can be controlled, the effect of PDI can be improved and the error rate of the wireless line can be improved.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing a transmitter of a spread spectrum communication system according to a first embodiment of the present invention.

FIG. 2 is a schematic block diagram showing a receiver of the spread spectrum communication system according to the first embodiment of the present invention.

FIG. 3 is a diagram showing waveforms of signals output from the correlator and the multiplier of FIG.

FIG. 4 is a block diagram showing details of a data demodulation unit in FIG.

5 is a flowchart showing a process of data demodulation in the data demodulation unit of FIG.

FIG. 6 is a schematic block diagram showing a transmitter of a spread spectrum communication system according to a second embodiment of the present invention.

FIG. 7 is a schematic block diagram showing a receiver of a spread spectrum communication system according to a second embodiment of the present invention.

FIG. 8 is a schematic block diagram showing a receiver of a spread spectrum communication system according to a third embodiment of the present invention.

FIG. 9 is a schematic block diagram showing a receiver of a spread spectrum communication system according to a fourth embodiment of the present invention.

10 is a diagram showing waveforms of general signals output from a correlator and a multiplier when the receiver of the spread spectrum communication system of FIG. 2 is used.

FIG. 11 is a diagram showing waveforms of signals output from a correlator and a multiplier when the receiver of FIG. 2 is used in the spread spectrum communication system according to the fifth embodiment of the present invention.

FIG. 12 is a diagram showing a data format according to a sixth embodiment of the present invention.

FIG. 13 is a schematic block diagram showing a transmitter of a conventional spread spectrum communication system.

FIG. 14 is a schematic block diagram showing a receiver of a conventional spread spectrum communication system.

[Explanation of symbols]

1 Data Generator 3 S / P Converter (Serial / Parallel Converter) 5, 7, 9, 71, 81, 133, 135, 199-2
09 Multiplier 11, 13, 15, 25, 91 Modulator 17, 19, 21, 57, 145, 147, 161-1
65 delay element 23 PN generator 27 multiplexer 29, 53, 59, 65, 101, 117-123, 1
41,143,167-181 Frequency converter 31 Power amplifier 33,51 Antenna 35,69 Local signal generator 55,111,113,115,151-159 Distributor 61,63,125-131,183-197 Correlator 67 Phase detector 73 Data demodulator 83 Selective delay unit 137, 211-215 Adder 217, 219, 221 Data demodulation circuit 223 P / S converter (parallel serial converter)

Claims (9)

[Claims] 1. A transmission spread code processing signal based on a spread code and a plurality of data processing signals based on a plurality of data processed by the spread code with respect to the transmission spread code processed signal are used as references. Receiving a transmission signal including a plurality of transmission delay data processing signals delayed by a continuous natural number times the delay time, processing the transmission signal, and first spreading code based on the transmission spreading code processing signal Generating a processed signal and a plurality of first delayed data processed signals based on the plurality of transmission delayed data processed signals; and the first spread code processed signal at the same time as the reference delay time. A second spread code processed signal delayed by a plurality of second delayed data processed signals obtained by delaying the plurality of first delayed data processed signals at the same time as the reference delay time. Generating a signal sequence consisting of the first spread code processed signal and the plurality of first delayed data processed signals, the second spread code processed signal and the plurality of second delayed data processed signals, And a signal sequence consisting of a signal sequence consisting of a plurality of signals, and generating a plurality of multiplication signals, the second spreading code processing signal and the first delay data processing among the plurality of multiplication signals. Generating a multiplication signal obtained by multiplying the signal as reference demodulation data; delaying the reference delay time from the reference demodulation data and the multiplication signal which is the basis of the reference demodulation data. And a step of repeatedly multiplying the multiplied signal and outputting the demodulated data as an updated reference, the data demodulating method. 2. A transmission spread code processed signal based on a spread code and a plurality of data processed signals based on a plurality of data processed by the spread code with respect to the transmission spread code processed signal are used as references. Receiving a transmission signal including a plurality of transmission delay data processing signals delayed by a continuous natural number times the delay time, processing the transmission signal, and first spreading code based on the transmission spreading code processing signal A processed signal, a plurality of first delayed data processed signals based on the plurality of transmission delayed data processed signals, a second spread code processed signal based on the spread code processed signal, and a plurality of delayed data processed signals Generating a plurality of second delayed data processing signals, and a third spreading code processing in which the first spreading code processing signal is delayed at the same time as the reference delay time. A signal, a plurality of third delay data processing signals obtained by delaying the plurality of first delay data processing signals at the same time as the reference delay time, and the same time as the reference delay time. Then, a plurality of the second spread code processed signals delayed from the second spread code processed signal and the plurality of second spread data processed signals delayed at the same time as the reference delay time. Generating a fourth delayed data processed signal, a signal sequence consisting of the first spread code processed signal and the plurality of first delayed data processed signals, the third spread code processed signal and the A signal sequence including a plurality of third delayed data processed signals is multiplied on the same time axis to generate a plurality of first multiplied signals, and the second spread code processed signal and the plurality of second spread code processed signals are generated. Of delayed data processing signals And a signal sequence composed of the fourth spread code processed signal and the plurality of fourth delayed data processed signals, on the same time axis, to generate a plurality of second multiplied signals. And a step of adding the plurality of first multiplication signals and the plurality of second multiplication signals to generate a plurality of addition signals; and, of the plurality of addition signals, the third and fourth spreading signals. A step of generating an addition signal based on the code-processed signal as reference demodulation data, the reference demodulation data, and the reference delay time delayed from the addition signal which is the basis of the reference demodulation data. And a step of repeatedly multiplying the added signal and outputting the demodulated data as an updated reference, the data demodulating method. 3. A transmission means for transmitting a transmission signal and a reception means for receiving the transmission signal, wherein the transmission means converts the data into a data generation means for generating data and a plurality of parallel signals. Serial/
Parallel conversion means, spreading code generation means for generating spreading code, transmission side multiplication means for multiplying the spreading code and the plurality of parallel signals to generate a plurality of spreading data, and transmission side local signal Transmitting side local signal generating means, first modulating means for modulating the transmitting side local signal with the plurality of spread data to generate a plurality of modulated spread data, and the transmitting side local signal with the spreading code. Second modulating means for modulating and generating a modulation spread code; and delaying each of the plurality of modulation spread data with respect to the modulation spread code by a continuous natural number times the reference delay time, A transmission-side delay unit that generates a plurality of delay modulation spread data, and a transmission signal output unit that multiplexes the plurality of delay modulation spread data and the modulation spread code, and transmits as the transmission signal. The receiving means divides the signal based on the transmission signal into two and generates two distribution signals; and one of the distribution signals has the same delay time as the reference. The receiving side delay means for delaying by time, the receiving side local signal generating means for generating a receiving side local signal, one of the delayed distribution signals and the receiving side local signal are multiplied to obtain a baseband signal, Correlating the signal with the spreading code to generate a first correlation signal, multiplying the other of the distributed signals with the receiving local signal;
A baseband signal, and the signal is correlated with the spread code to generate a second correlation signal, and the first correlation signal and the second correlation signal are multiplied,
The receiving side multiplication means for generating pre-demodulation data, and the demodulation means for demodulating the data based on the pre-demodulation data, wherein the demodulation means is based on the spread code and is not based on the data. The pre-demodulation data is generated as reference demodulation data based on the correlation signal of, and the reference demodulation data and the reference delay from the pre-demodulation data that is the basis of the reference demodulation data are generated. A spread spectrum communication system in which an operation of multiplying time-delayed pre-demodulation data and outputting it as updated reference demodulation data is repeated. 4. A transmission means for transmitting a transmission signal, and a reception means for receiving the transmission signal, wherein the transmission means converts the data into a plurality of parallel signals and a data generation means for generating data. Serial/
Parallel conversion means, spreading code generating means for generating a spreading code, transmission side multiplying means for multiplying the spreading code and the plurality of parallel signals to generate a plurality of spreading data, and for the spreading code, Each of the plurality of spread data that is a baseband signal is delayed by a continuous natural number times the reference delay time to generate a plurality of delay spread data, and a transmission-side delay unit, and the plurality of delay spreads. Combining means for combining the data and the spread code to generate a combined signal; transmitting side local signal generating means for generating a transmitting side local signal; and the transmitting side local signal being modulated by the combined signal. , A transmission signal output means for transmitting as the transmission signal, the reception means for receiving side local signal generating means for generating a reception side local signal, and a signal based on the transmission signal. And a frequency converter for multiplying the receiving side local signal to generate a baseband signal, a divider for dividing the baseband signal into two and generating a split signal, and one of the split signals. , The receiving side delay means that delays at the same time as the reference delay time, and one of the delayed distribution signals is correlated with the spread code to generate a delayed correlation signal, and the other of the distribution signals is generated. Correlation means for taking a correlation with a spread code and generating a correlation signal; reception side multiplication means for multiplying the delayed correlation signal and the correlation signal to generate pre-demodulation data; Demodulation means for demodulating data, the demodulation means, based on the spread code, as the reference demodulation data based on the pre-demodulation data based on the delayed correlation signal not based on the data The demodulated data serving as the reference is multiplied by the pre-demodulation data delayed from the pre-demodulation data serving as the basis of the demodulation data serving as the reference, and the pre-demodulation data delayed to become the updated reference. A spread spectrum communication system that repeats the operation of outputting as demodulated data. 5. A transmission means for transmitting a transmission signal, and a reception means for receiving the transmission signal, wherein the transmission means converts the data into a data generation means for generating data and a plurality of parallel signals. Serial/
Parallel conversion means, spreading code generation means for generating spreading code, transmission side multiplication means for multiplying the spreading code and the plurality of parallel signals to generate a plurality of spreading data, and transmission side local signal Transmitting side local signal generating means, first modulating means for modulating the transmitting side local signal with the plurality of spread data to generate a plurality of modulated spread data, and the transmitting side local signal with the spreading code. Second modulating means for modulating and generating a modulation spread code; and delaying each of the plurality of modulation spread data with respect to the modulation spread code by a continuous natural number times the reference delay time, A transmission-side delay unit that generates a plurality of delay modulation spread data, and a transmission signal output unit that multiplexes the plurality of delay modulation spread data and the modulation spread code, and transmits as the transmission signal. The receiving means divides the signal based on the transmission signal into two, and generates two initial distribution signals; and one of the initial distribution signals and a delay time serving as the reference. The receiving side delay means for delaying at the same time, the first distributing means for distributing one of the delayed initial distribution signals to generate a first distribution signal, and the other of the initial distribution signals. Second distributing means for dividing into two and generating a second distributing signal; receiving side local signal generating means for generating a receiving side local signal; one of the first distributing signals and the receiving side local The cos component of the signal is multiplied to obtain a pseudo baseband signal, the signal is correlated with the spreading code to generate a first cos correlation signal, and the other of the first distributed signals and the receiving side local signal Multiplies the sin component of First base correlation means for generating a first sin correlation signal by correlating the signal with a similar baseband signal by the spread code, and cos of one of the second distribution signal and the reception side local signal The component is multiplied to form a pseudo baseband signal, the signal is correlated with the spread code to generate a second cos correlation signal, and the other of the second distributed signal and the sin component of the reception side local signal. To obtain a pseudo baseband signal, the signal is correlated with the spread code to generate a second sin correlation signal, the first cos correlation signal, and the second cos correlation signal. and a cos correlation signal to generate a first multiplication signal, the first si
An n-correlation signal is multiplied by the second sin correlation signal to generate a second multiplication signal, and a reception side multiplication means is added, and the first and second multiplication signals are added to generate pre-demodulation data. Means and demodulating means for demodulating the data based on the pre-demodulation data, wherein the demodulating means is based on the spreading code and uses the first cos correlation signal not based on the data and the spreading code. The pre-demodulation data based on the first sin correlation signal not based on the data is generated as reference demodulation data, and the reference demodulation data and the reference demodulation data base are generated. Spread spectrum communication in which the operation of multiplying the pre-demodulation data by the reference delay time and the delayed pre-demodulation data and outputting as the updated reference demodulation data is repeated. system. 6. A transmission means for transmitting a transmission signal, and a reception means for receiving the transmission signal, wherein the transmission means converts the data into a plurality of parallel signals and a data generation means for generating data. Serial/
Parallel conversion means, spreading code generating means for generating a spreading code, transmission side multiplying means for multiplying the spreading code and the plurality of parallel signals to generate a plurality of spreading data, and for the spreading code, Each of the plurality of spread data that is a baseband signal is delayed by a continuous natural number times the reference delay time to generate a plurality of delay spread data, and a transmission-side delay unit, and the plurality of delay spreads. Combining means for combining the data and the spread code to generate a combined signal; transmitting side local signal generating means for generating a transmitting side local signal; and the transmitting side local signal being modulated by the combined signal. And a transmission signal output unit that transmits the transmission signal, wherein the reception unit divides a signal based on the transmission signal into two, and generates two initial distribution signals, A reception-side local signal generator means for generating a signal-side local signal, c of one and the reception side local signal of the initial distribution signal
first frequency conversion means for multiplying the os component and outputting a first signal of the pseudo baseband; s of the other of the initial distribution signal and the reception side local signal.
second frequency conversion means for multiplying the in component and outputting a second signal of the pseudo baseband; a first frequency conversion means for dividing the first signal of the pseudo baseband into two and generating a first divided signal; One distributing means, second distributing means for distributing the second signal of the pseudo baseband into two, and generating a second distributing signal; and one of the first distributing signal as the reference. A first receiving-side delay unit that delays for the same time as the delay time, and a second receiving-side delay unit that delays one of the second distributed signals for the same time as the reference delay time. , One of the delayed first distribution signals is correlated with the spreading code to generate a first delayed correlation signal, and the other of the first distribution signals is correlated with the spreading code to obtain the first delayed correlation signal. First correlating means for generating a correlating signal and delaying the second distribution signal A second correlating means for correlating one of them with the spreading code to generate a second delayed correlation signal, and the other of the second distributed signals with the spreading code to generate a second correlation signal. And multiplying the first delayed correlation signal and the first correlation signal to generate a first multiplication signal, multiplying the second delayed correlation signal and the second correlation signal, Receiving-side multiplying means for generating a multiplication signal of 2, and adding the first multiplication signal and the second multiplication signal,
The demodulation means includes an addition means for generating pre-demodulation data and a demodulation means for demodulating the data based on the pre-demodulation data, wherein the demodulation means is based on the spread code and is not based on the data. The pre-demodulation data based on the correlation signal and the second delayed correlation signal not based on the data based on the spread code, is generated as reference demodulation data, and the reference demodulation data, The spectrum is repeatedly obtained by multiplying the pre-demodulation data, which is the basis of the demodulation data that is the reference, by the delay time that is the reference and the pre-demodulation data that is delayed, and outputting as the updated demodulation data that is the reference. Spread communication system. 7. A signal based on the last transmission signal having the largest delay time among signals based on the transmission signal,
7. The time interval between a signal based on the first transmission signal that follows the signal based on the last transmission signal having the longest delay time is different from the reference delay time. The spread spectrum communication system according to item 1. 8. The spread spectrum communication according to claim 3, wherein the preamble portion of the data packet is not multiplexed, and the portion containing the data to be information is multiplexed. system. 9. The demodulation means includes a filter for extracting only the pre-demodulation data in a predetermined time range from the pre-demodulation data having a time spread; and the pre-demodulation data extracted in the predetermined time range. And a control means for controlling the filter and the integration means, using as a pilot signal a signal output from a path that does not delay or a signal output at a timing earlier than the demodulated data before demodulation, The spread spectrum communication system according to any one of claims 3 to 8.