JPH0955714A - Spread spectrum communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spread spectrum communication system which can improve error rate characteristics. SOLUTION: A transmitter of this spread spectrum communication system includes a data generation part 1, a differential encoding part 3, an S/P conversion part 5, multipliers 11-17, a PN generator 7, a local signal generator 9, modulators 19-25, delay elements 27-33, a multiplexer 35, a frequency conversion part 37, a power amplification part 39, and a transmitting antenna 41. After parallel signals P1-P4 are multiplied by the spread code from the PN generator 7, they are delayed by the delay elements 27-33 for multiplexing. Further, time differences between the delay times are arbitrary times that are mutually more than one chip. Consequently, the error rate characteristics can be improved and deterioration of correlation output is prevented to prevent it from becoming difficult to perform demodulation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spread spectrum communication system, and more particularly to a spread spectrum communication system capable of preventing deterioration of communication characteristics and performing multiplex high speed communication.

[0002]

2. Description of the Related Art In conventional data communication, communication using a narrow band modulation method is generally used. Although demodulation in the receiver can be realized by a relatively small circuit, they have a drawback that they are vulnerable to multipath and narrow band colored noise like indoors (office, factory, etc.).

[0003] On the other hand, a spread spectrum communication system spreads the spectrum of data with a spreading code.
Since transmission is performed over a wide band, there is an advantage that these disadvantages can be eliminated.

Even in Japan, IS in the 2.45 GHz band
It has been approved for use in the M band and is about to be put into practical use. In this band, the allowed band is 26M.
It is in the Hz band, and the spreading factor is 10 or more. Therefore, for example, when the BPSK modulation method is used, the data rate that can be transmitted is about 1.3 MHz.

On the other hand, however, high-speed communication is desired, and in order to realize this, it has become necessary to perform multiplex transmission. In this case, as one method, a method has been proposed in which data is spread with the same spreading code, and the data is delayed and multiplexed. This will be described in detail.

FIG. 38 is a schematic block diagram showing a transmitter of a conventional spread spectrum communication system. Referring to FIG. 38, the transmitter of the conventional spread spectrum communication system includes a serial / parallel converter 461 and a spread modulator 46.
3, 465, 467, delay circuits 469, 471, 47
3, spread code generator (PN generator) 475, synchronization circuit 4
77, adder 479, amplifier 481, local oscillator 48
3, synchronization spreading code generator (synchronization PN generator) 48
5, a multiplication circuit 487 and a mixing circuit 489 are included.

In the transmitter of the conventional spread spectrum communication system, the serial baseband data S is converted into N channel parallel data by the serial / parallel converter 461. On the other hand, the first spreading code generated by the PN generator 475 is input to the N kinds of delay circuits 469 to 473. The delay time is selected to be shorter than the time for one cycle of the spread code pattern, and the delay time in each delay circuit is different.

Further, the synchronization PN generator 485 has a first
The second spreading code is generated in synchronization with the spreading code of. Second
The spreading code is used to supplement and maintain synchronization with the receiving side.

The N-channel parallel data output from the serial / parallel converter 461 is the spread modulator 463.
˜467, spreading modulation is performed by N kinds of first spreading codes having different phases. The spread-modulated data is analog-added by the adder 479 and converted into one-channel data.

The mixing circuit 489 mixes the output of the synchronizing PN generator 485 and the output of the local oscillator 483, and the multiplier 487 multiplies the output of the adder 479 and the output of the mixing circuit 489. The multiplied data is amplified by the amplifier 481 and transmitted as a radio signal to the outside from a duplexer (not shown) through an antenna (not shown).

[0011]

The transmitter of the conventional spread spectrum communication system described above is disclosed in Japanese Patent Laid-Open No. 4-3.
As disclosed in Japanese Patent No. 60434, this publication mentions that the delay times of the delay circuits 469 to 473 are different from each other. However, it has not been shown that the delay is more than one chip. If the delay is within 1 chip, there is a problem that the correlation outputs overlap in the receiver and the error rate characteristic deteriorates. This will be described in detail.

FIG. 39 is a diagram showing the correlation output on the receiving side when the delay is within one chip on the transmitting side. The horizontal axis indicates time t. It can be seen from FIG. 39 that the two correlation waveforms overlap. In this case, at the sample point SP, the correlation output deteriorates due to the influence of the signal component (the portion indicated by the arrow a) of the overlapping portion, and the error rate characteristic at the time of reception deteriorates. This is because autocorrelation characteristics in spread spectrum are independent if they are separated by one chip or more, but are not independent within that range.

Further, in the transmitter of the conventional spread spectrum communication system, the first spread code is delayed and spread by multiplying the delayed first spread code by the parallel-converted data. There is. In this method, the change point of data and the start of the spread code are deviated. Therefore, there is a problem that demodulation using a correlator becomes difficult. This will be described in detail.

FIG. 40 is a diagram showing parallel-converted data (N-channel parallel data) and the first spreading code in FIG.

FIG. 40A shows parallel-converted data in the nodes a1, a2 ... aN of the transmitter shown in FIG. The data of each of the nodes a1 to aN have the same timing.

FIG. 40A shows the first spreading code in the node b of the receiver shown in FIG. Note that one period of the spread code is T.

FIG. 40C shows spreading codes in the nodes c1, c2 ... cN of the receiver shown in FIG. The first spread codes at these nodes c1 to cN are delayed by the corresponding delay circuits 469 to 473 by delay times τ _{1 to} τ _N , respectively. Therefore, FIG.
As shown in (a) and (c), the timing of the first spreading code and the timing of the parallel-converted data are deviated. The effect when the timing of the first spreading code and the timing of the parallel-converted data are deviated will be described in detail.

FIG. 41 is a diagram for explaining an adverse effect caused by the deviation of the timing of the first spread code and the timing of the data converted into parallel in the transmitter.

FIG. 41A shows a node a in FIG.
1 shows the parallel-converted data in 1. In addition,
B indicates 1 bit of data.

FIG. 41 (b) shows the spreading code at the node b in FIG. FIG. 41 (c) shows the spreading code at the node c1 in FIG. As you can see from these figures, for parallel converted data,
The first spreading code is delayed by τ ₁ and is out of timing.

FIG. 41D shows the correlation output in the receiver (not shown) when the timing of the parallel-converted data and the timing of the first spreading code are not shifted.
FIG. 41 (e) shows the correlation output in the receiver when the timings of the parallel-converted data and the first spreading code are shifted by the delay time τ ₁ .

As shown in FIGS. 41 (d) and 41 (e), when the timing of parallel-converted data deviates from the timing of the first spreading code, the correlation output in the receiver becomes small. This is because the input signal (data) is inverted in the middle of the first spreading code.
This is because the spread code of is different from the code held by the correlator of the receiver (not shown). This will be described in detail.

FIG. 42 is a diagram showing a specific example of the correlation output when the timing of the data and the timing of the first spreading code match.

The row a indicates data. The row of b is the first
The spreading code of is shown. The first spreading code is 7 chips. That is, the first spreading code is (101010
1).

The line c shows the result of multiplying the data by the first spreading code. The row of d shows the correlator code of the correlator of the receiver. The row of e shows the correlation output.

FIG. 43 is a diagram showing a specific example of the correlation output in the receiver when the timings of the data and the first spreading code are deviated.

Referring to FIG. 43, the row a indicates data. The row of b shows the first spreading code. This first spreading code is 7 chips like the first spreading code shown in FIG.

Row c is the result of multiplying the data by the first spreading code. The row of d shows the correlator code of the correlator of the receiver. The row of e shows the correlation output.

As shown in the row a and the row b, the timings of the data and the first spreading code are deviated. In FIG. 42, the correlation output based on the second data 1 from the left is 7
It is. On the other hand, in FIG. 43, the correlation output based on the second data 1 from the left is 5. From the comparison between FIG. 42 and FIG. 43, it can be seen that the correlation output is deteriorated when the data and the first spreading code are deviated. Similarly, with respect to the third data 0 from the left, the correlation output is deteriorated.

In FIG. 43, the second data 1 from the left
The reason why the correlation output based on is 5 instead of 7 will be described. The first spreading code is behind the data. Therefore, the last information 1 (indicated by arrow f) of the second spreading code from the left corresponding to the second data 1 from the left.
Is not multiplied by the second data 1 from the left,
The third data 0 from the left coming next (indicated by arrow g)
Will be multiplied by. Therefore, 2 from the left of the line c
As shown in the second, the result of multiplying the spread code by the data is 1010100. On the other hand, in FIG. 42, as shown in the second row from the left in the row of c, the result of multiplying the data by the first spreading code is 1010101.

The correlator code is the same in FIGS. 42 and 43. As a result, the correlation output based on the second data 1 from the left in FIG. 42 is 7, and the correlation output based on the data 1 in FIG. 43 is 5, which deteriorates. The same applies to the correlation output based on the third data 0 from the left.

From the above, it has become clear that the demodulation becomes difficult when the timings of the data and the first spreading code are deviated.

Further, in the spread spectrum communication system disclosed in Japanese Patent Laid-Open No. 5-252141, the delay when delaying and multiplexing is 1 chip or 2
It has been shown that a chip interval is shifted and a code whose autocorrelation has a zero lobe at a constant cycle is obtained. However, it is not shown that the time is arbitrary for one chip or more.

In this case, due to the peculiarity of the code, the delayable time is restricted to the point where the autocorrelation of the code becomes 0, that is, for example, 2 chips or 1 chip, and the spread spectrum communication system can be designed freely. There was a problem that the degree was low.

Further, for example, when there is a delayed wave due to multipath, the delayed wave may spread over a time of several chips. In such a case, when the delay interval is 2 chips, the delayed waves due to the space overlap, which causes a problem that the characteristics deteriorate.

Further, as a demodulation system, the receiver of the spread spectrum communication system of the above-mentioned Japanese Patent Laid-Open No. 4-360434 carries out active despreading by applying a spreading code. Further, the receiver of the spread spectrum communication system disclosed in Japanese Patent Laid-Open No. 5-252141 described above samples the output of the matched filter (correlator) as it is to obtain demodulated data.

In this case, when a number of waves are multiplexed and input due to multipath, etc., only one wave which has received interference is demodulated, and the characteristic is deteriorated. was there.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a spread spectrum communication system capable of multiplex communication without deteriorating the error rate characteristic.

Another object of the present invention is to provide a spread spectrum communication system capable of performing multiplexed communication by preventing deterioration of correlation output and preventing difficulty in demodulation.

Still another object of the present invention is to provide a spread spectrum communication system having a large degree of freedom in design.

Still another object of the present invention is to provide a spread spectrum communication system capable of improving communication characteristics in multipathing.

[0042]

A spread spectrum communication system according to claim 1 of the present invention comprises a transmitting means and a receiving means. The transmission means includes serial / parallel conversion means, spread code generation means, multiplication means, modulation means, delay means and transmission signal output means.

The serial / parallel conversion means converts the data string into a plurality of parallel signals. The spreading code generation means generates a spreading code. The multiplying unit multiplies the plurality of parallel signals by the spread code to generate a plurality of spread signals. The modulation means modulates the plurality of spread signals to generate a plurality of intermediate frequency signals. The delay means has a plurality of different delay times. Then, the delay means delays the plurality of intermediate frequency signals with a plurality of different delay times, respectively, and generates a plurality of delayed signals. The transmission signal output means is
A plurality of delayed signals are combined and output as a transmission signal.

The plurality of different delay times in the delay means have an arbitrary time difference of one chip or more.

As described above, in the spread spectrum communication system according to the first aspect of the present invention, a plurality of intermediate frequency signals obtained by modulating a plurality of spread signals obtained by multiplying a plurality of parallel signals by a spread code are delayed by different delay times. By doing so, the data is multiplexed. Therefore, the timing of the parallel signal and the timing of the spread code do not shift due to the delay for multiplexing, and the two timings match.

As a result, in the spread spectrum communication system according to the first aspect of the present invention, it is possible to prevent deterioration of the correlation output on the receiving side, avoid the difficulty of demodulation, and perform multiplex communication.

Furthermore, since the time difference between the delay times is 1 chip or more, the signal to be demodulated and the signal next to the signal do not overlap with each other, and the error rate characteristic can be improved.

Furthermore, since the delay time is set to an arbitrary time without limitation, the degree of freedom in system design can be increased.

A spread spectrum communication system according to claim 2 of the present invention comprises a transmitting means and a receiving means. The transmitting means is a serial / parallel converting means, a spreading code generating means,
It includes multiplication means, delay means and transmission signal output means.

The serial / parallel conversion means converts the data string into a plurality of parallel signals. The spreading code generation means generates a spreading code. The multiplying unit multiplies the plurality of parallel signals by the spread code to generate a plurality of spread signals. The delay means has a plurality of different delay times. The delay means delays the plurality of baseband spread signals by a plurality of different delay times, respectively, to generate a plurality of delay signals.

The transmission signal output means multiplexes a plurality of delayed signals and outputs them as a transmission signal. The plurality of different delay times have an arbitrary time difference of 1 chip or more.

As described above, in the spread spectrum communication system according to claim 2 of the present invention, multiplexing is performed by delaying a plurality of spread signals obtained by multiplying a plurality of parallel signals by a spread code. Therefore, the timing of the spread code and the timing of the parallel signal do not shift due to the delay for multiplexing, and the two timings match.

As a result, in the spread spectrum communication system according to the second aspect of the present invention, it is possible to prevent the deterioration of the correlation output on the receiving side, avoid the difficulty of demodulation, and perform multiplexed communication.

Further, since the delay time is set to 1 chip or more, the signal to be demodulated and the signal next to the signal do not overlap with each other, and the error rate characteristic can be improved.

Furthermore, since the time difference between the delay times is not set as an arbitrary time, the degree of freedom in system design can be increased.

Further, since the spread signal which is the base band is delayed, the delay means can be constituted by a digital circuit, and the system can be miniaturized and highly integrated.

A spread spectrum communication system according to claim 3 of the present invention includes transmitting means and receiving means. The transmission means includes a serial / parallel conversion means, a first delay means, a spread code generation means, a second delay means, a multiplication means and a transmission signal output means.

The serial / parallel conversion means converts the data string into a plurality of parallel signals. The first delay means is
It has a plurality of different delay times. Then, the first delay means delays the plurality of baseband parallel signals by a plurality of different delay times, respectively, and generates a plurality of delayed parallel signals.

The spread code generating means generates a spread code. The second delay means has the same plurality of delay times as the plurality of different delay times in the first delay means. Then, the second delay means delays the spread code with a plurality of delay times to generate a plurality of delay spread codes.

The multiplying means multiplies the plurality of delayed parallel signals by the plurality of delay spread codes to generate a plurality of spread signals. The transmission signal output means multiplexes a plurality of signals based on the plurality of spread signals and outputs them as a transmission signal.

The multiplication means multiplies the delayed parallel signal having the same delay time by the delay spread code. Also,
The plurality of different delay times have an arbitrary time difference of 1 chip or more.

As described above, in the spread spectrum communication system according to claim 3 of the present invention, the parallel signal corresponding to the delay spread code is delayed by the same delay time as the delay time of the delay spread code. Therefore, the timing of the delayed parallel signal and the timing of the delay spread code do not shift due to the delay for multiplexing, and the two timings match.

As a result, in the spread spectrum communication system according to claim 3 of the present invention, it is possible to prevent the deterioration of the correlation output on the receiving side, avoid the difficulty of demodulation, and perform multiplex communication.

Further, since the time difference between the delay times is 1 chip or more, the signal to be demodulated and the signal next to the signal do not overlap with each other, and the error rate characteristic can be improved.

Furthermore, since the time difference between the delay times is set to an arbitrary time and no limitation is set, the degree of freedom in system design can be increased.

Furthermore, since the parallel signal, which is the base band, is delayed, the delay means can be configured by a digital circuit, and the system can be downsized and highly integrated.

A spread spectrum communication system according to claim 4 of the present invention includes transmitting means and receiving means. The transmission means includes serial / parallel conversion means, latch means, spread code generation means, delay means, multiplication means, transmission signal output means and latch control means.

The serial / parallel conversion means converts the data string into a plurality of parallel signals. The latch means latches a plurality of parallel signals to generate a plurality of latch signals.

The spread code generating means generates a spread code. The delay means has a plurality of different delay times. The delay means delays the spread code with a plurality of different delay times to generate a plurality of delay spread codes.

The multiplication means multiplies a plurality of latch signals by a plurality of delay spread codes to generate a plurality of delay spread codes.

The transmission signal output means multiplexes signals based on a plurality of delay spread signals and outputs them as a transmission signal. The latch control means generates a plurality of latch control signals. The latch control signal has the same timing as the start chip of the corresponding delay spread code.

Further, the latch means latches a plurality of parallel signals by a plurality of latch control signals. As a result, the timings of the plurality of latch signals multiplied by the multiplication means coincide with the timings of the plurality of delay spread codes. The plurality of different delay times have an arbitrary time difference of 1 chip or more.

As described above, in the spread spectrum communication system according to claim 4 of the present invention, the timing of the latch signal and the timing of the delay spread code are made coincident by providing the latch means and the latch control means.

As a result, in the spread spectrum communication system according to the fourth aspect of the present invention, it is possible to prevent the deterioration of the correlation output on the receiving side, avoid the difficulty of demodulation, and perform multiplex communication.

Further, since the time difference between the delay times is 1 chip or more, the signal to be demodulated and the signal next to the signal do not overlap with each other, and the error rate characteristic can be improved.

Furthermore, since the time difference between the delay times is set to an arbitrary time and no limitation is set, the degree of freedom in system design can be increased.

In a spread spectrum communication system according to claim 5 of the present invention, in the spread spectrum communication system according to any one of claims 1 to 4, the transmitting means is a difference device for performing differential encoding of a data string. It further includes a dynamic encoding means.

The differential encoding means is provided before the serial / parallel conversion means. The serial / parallel conversion means receives the differentially encoded data string.

The receiving means includes a demodulating means for demodulating based on the received transmission signal. The demodulation means includes a differential decoding means and an integration means.

The differential decoding means performs differential decoding using the signal based on the transmission signal to generate a differential decoded signal. The integrating means integrates the differential decoded signal having a temporal spread within a predetermined time range.

As described above, in the spread spectrum communication system according to claim 5 of the present invention, the transmitting means performs multiplexing by converting the differentially encoded data sequence into a plurality of parallel signals. Then, the receiving means uses a signal based on the transmission signal from such a transmitting means,
Differential decoding is performed and the differential decoded signal is integrated within a predetermined time range. Therefore, the time interval between signals to be differentially decoded is short and the change in the path between them is small, so that the effect of PDI is improved.

As a result, in the spread spectrum communication system according to claim 5 of the present invention, it is possible to improve the communication characteristics in multipathing.

In a spread spectrum communication system according to claim 6 of the present invention, in the spread spectrum communication system according to any one of claims 1 to 4, the transmitting means further includes a first parallel / delay control means. Contains. The first parallel / delay control means sets the number (multiplex number) of a plurality of parallel signals and a plurality of different delay times according to the use environment.

As a result, in the spread spectrum communication system according to claim 6 of the present invention, the line efficiency can be improved.

In a spread spectrum communication system according to claim 7 of the present invention, in the spread spectrum communication system according to any one of claims 1 to 4, the transmitting means is a data generating means and a second parallel / delay control. It also includes means.

The data generating means, depending on the contents of the information,
A data string is generated by changing the data rate.

The second parallel / delay control means sets the number (multiplex number) of a plurality of parallel signals and a plurality of different delay times so that the symbol rate becomes constant regardless of the change of the data rate. . Here, the symbol rate indicates the rate after serial / parallel conversion.

As described above, in the spread spectrum communication system according to the seventh aspect of the present invention, the symbol rate is always kept constant when the multi-rate method in which the data rate is changed according to the content of information is used.

As a result, in the spread spectrum communication system according to claim 7 of the present invention, since communication can be performed while keeping the transmission bandwidth constant, it is not necessary to control the frequency channel and the multirate can be easily realized. .

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 1 to 4, a time difference between adjacent signals in a plurality of multiplexed signals is provided. A plurality of different delay times are set so that is constant.

In this way, the delay time is set so that the signals have a constant time interval. As a result, in the spread spectrum communication system according to claim 8 of the present invention, since only one path is required to be delayed on the receiving side, the circuit scale of the system can be greatly reduced.

[0092]

DESCRIPTION OF THE PREFERRED EMBODIMENTS 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.

Referring to FIG. 1, the transmitter of the spread spectrum communication system according to the first embodiment has a data generator 1, a differential encoder 3, a serial / parallel converter (S / P).
(Conversion unit) 5, spreading code generator (PN generator) 7, local signal generator 9, multipliers 11, 13, 15, 17, modulators 19, 21, 23, 25, delay elements 27, 29, 3
1, 33, a multiplexer 35, a frequency converter 37, a power amplifier 39, and a transmission antenna 41.

The data generated by the data generator 1 is differentially encoded by the differential encoder 3. The differentially encoded data is converted into a plurality of parallel signals (a plurality of parallel data) by the S / P converter 5. The PN generator 7 generates a spreading code. The multipliers 11 to 17 multiply the plurality of parallel signals P1 to P4 and the spread code from the PN generator 7 to generate spread signals M1 to M4.

The modulators 19 to 25 use the local signal from the local signal generator 9 to modulate the spread signals M1 to M4 into intermediate frequency signals (IF signals) I1 to I4. The delay elements 27 to 33 have the intermediate frequency signals I1 to I4.
And delay signals D1 to D4 are generated.

The delay times of the delay elements 27 to 33 are different. Furthermore, the delay times of the delay elements 27 to 33 have an arbitrary time difference of 1 chip or more. Such a delay time setting will be referred to as a "first delay time setting method".

The delay signals D1 to D4 are multiplexed by the multiplexer 35. The combined signal is used by the frequency conversion unit 37.
The frequency is converted by. The frequency-converted signal is amplified by the power amplification unit 39 and output as a transmission signal by the transmission antenna 41.

FIG. 2 is a diagram showing the timing of the parallel signals P1 to P4 and the timing of the spread code in FIG. Referring to FIG. 2, the upper part shows, for example, the parallel signal P of FIG.
1 is shown. “A” indicates one bit of data.

In FIG. 2, the lower part shows spreading codes. b indicates one cycle of the spread code.

As shown in FIG. 2, the timing of the parallel signal P1 and the timing of the spread code coincide with each other. In addition, the timings of the parallel signals P2 to P4 and the timing of the spread code also coincide with each other.

As described above, in the first embodiment, the intermediate frequency signals I1 to I4 obtained by modulating the spread signals M1 to M4 obtained by multiplying the parallel signals P1 to P4 by the spreading code.
Are delayed by the delay elements 27 to 33 to multiplex the data. Therefore, the parallel signals P1 to P
The timing of 4 and the timing of the spreading code do not shift due to the delay for multiplexing, and the two timings match.

As a result, in the first embodiment,
It is possible to prevent deterioration of the correlation output on the receiving side, avoid the difficulty of demodulation, and perform multiplexed communication.

Further, since the time difference between the delay times is set to 1 chip or more, the signal to be demodulated and the signal next to the signal do not overlap with each other, and the error rate characteristic can be improved. That is, on the receiving side, signals are not deteriorated due to interference between delayed and multiplexed signals, and the error rate characteristic can be improved.

Furthermore, since the time difference between the delay times is set to an arbitrary time without limitation (one chip or two chips in the prior art) as in the prior art, the hardware, that is, the spread spectrum communication system The degree of freedom in design can be increased.

The shortest delay time among the delay elements 27 to 33 in FIG. 1 can be set to zero. Also in this case, the same effect as described above can be obtained.

Further, as an equivalent device, one of the delay elements 27 to 33 can be omitted.

The differential encoding in the differential encoding unit 3 of FIG. 1 will be described in detail. In DBPSK or DQPSK modulation, data is discriminated from the phase difference from the signal one bit (one symbol) before. Therefore, on the transmission side, data to be transmitted is modified. This is differential coding.

Considering DBPSK as an example, when the data is "1", the phase difference is 0, and when the data is "0", the phase difference is 180 °. It is encoding. explain in detail.

FIG. 3 is a diagram for explaining differential encoding in the differential encoding unit 3 of FIG.

FIG. 3A shows information data.
FIG. 3B shows the transmission phase. FIG. 3 (c)
The phase difference is shown. FIG.3 (d) shows at the receiving side.
The demodulated data is shown.

With reference to FIG. 3, let us consider the leftmost data, transmission phase, phase difference and demodulation data. Note that 0 ° on the leftmost side of (b) is set as an initial value. When the data is "1", as described above,
Since the transmission phase is created so that the phase difference becomes 0, the transmission phase for the data “1” becomes 0 ° as shown in the second from the left in (b). The transmission phase is similarly obtained for other data.

In this way, the differential encoder 3 of FIG.
Although the transmission phase is created, the angle is not actually transmitted. Therefore, in the DBPSK modulation, the transmission signal (transmission data) is 1 when the transmission phase is 0 ° and 0 when the transmission phase is 180 °. Will be sent. That is, the differential encoding unit 3 creates transmission data corresponding to the transmission phase from the information data. DBPSK is differential two-phase phase shift keying, and DQPSK is differential four-phase phase shift keying.

Further, in a plurality of multiplexed signals, the delay times of the delay elements 27 to 33 are set so that the time difference between the adjacent signals becomes constant. The delay element 2
As described above, the delay times of 7 to 33 have an arbitrary time difference of 1 chip or more. Such a delay time setting will be referred to as a "second delay time setting method". For example, the delay time of the delay element 27 is set smaller than the delay times of the other delay elements 29 to 33, and the delay time is set as the reference delay time. Then, the delay times of the other delay elements 29 to 33 are set to be a specified number of times the delay time serving as the reference of the delay element 27.

That is, the difference in delay time between the delay element 27 and the delay element 29, the difference in delay time between the delay element 29 and the delay element 31, and the difference in delay time between the delay element 31 and the delay element 33 are used as the reference of the delay element 27. The delay time is set to be the same.

By doing so, the receiving side needs only one path to be delayed, so that the circuit scale of the system can be greatly reduced. Also, regardless of the number of multiplexes, there is only one delay path on the receiving side, so
Even if the number of multiplexes increases, the circuit scale of the system is constant and does not increase.

(Second Embodiment) In the spread spectrum communication system according to the first embodiment, the intermediate frequency signals I1 to I4 are delayed and multiplexed, but the spread spectrum according to the second embodiment is used. In a communication system, multiplexing is performed by delaying baseband signals.

FIG. 4 is a schematic block diagram showing a transmitter of a spread spectrum communication system according to the second embodiment of the present invention.

Referring to FIG. 4, the transmitter of the spread spectrum communication system according to the second embodiment includes a data generator 1, a differential encoder 3, an S / P converter 5, a PN generator 7,
Local signal generator 9, multipliers 11, 13, 15, 1
7, delay elements 27, 29, 31, 33, a multiplexer 35, a modulator 51, a frequency converter 37, a power amplifier 39 and a transmission antenna. The same parts as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

The delay elements 27 to 33 are multipliers 11 to 17 respectively.
The delayed multiplying signals M1 to M4 are delayed by different delay times to generate delayed signals D1 to D4. Here, the multiplication signals M1 to M4 are baseband signals, and the delay elements 27 to 33 delay the baseband signals.

Further, the parallel signals P1 to P4 and the multiplication signals M1 to M4 obtained by multiplying the spread codes are delayed and multiplexed. Therefore, the timing of the spread code and the parallel signal P
The timings 1 to P4 do not shift due to the delay due to multiplexing, and the two timings match.

The multiplexer 35 multiplexes the delay signals D1 to D4. The modulator 51 modulates the combined signal using the local signal from the local signal generator 9 to form an intermediate frequency signal. The frequency conversion unit 37 frequency-converts this intermediate frequency signal. The signal frequency-converted by the frequency converter 37 is amplified by the power amplifier 39,
It is transmitted by the transmitting antenna 41.

As described above, in the second embodiment, the timing of the spread code and the timing of the parallel signals P1 to P4 are matched. As a result, it is possible to prevent the deterioration of the correlation output on the receiving side, avoid the difficulty of demodulation, and perform multiplex communication.

Further, since the time difference between the delay times is 1 chip or more, the demodulated signal and the signal next to the signal do not overlap with each other, and the error rate characteristic can be improved. That is, on the receiving side, signals are not deteriorated due to interference between delayed and multiplexed signals, and the error rate characteristic can be improved.

Furthermore, since the time difference between the delay times is set to an arbitrary time without any limitation (conventionally, one chip or two chips) as in the prior art, the hardware, that is, the spread spectrum communication system The degree of freedom in design can be increased.

The shortest delay time among the delay elements 27 to 33 in FIG. 4 can be set to 0. Also in this case, the same effect as described above can be obtained. Also, as an equivalent, one of the delay elements 27-33 can be omitted. Further, as in the case of the first embodiment, the second delay time setting method can be used for the delay times of the delay elements 27 to 33. That is, the delay times of the delay elements 27 to 33 are set so that the time difference between the adjacent signals is constant and becomes an arbitrary time of one chip or more in the multiple multiplexed signals. In this case, since the receiving side needs only one delay path, the circuit scale of the system is significantly reduced. Further, since the delay path is one regardless of the number of multiplexing, the circuit scale of the system does not increase even if the number of multiplexing increases.

The baseband multiplication signals M1 to M4
Since the signals are delayed and multiplexed, digital delay elements can be used as the delay elements 27 to 33, and the transmitter can be downsized and highly integrated.

(Third Embodiment) In the first and second embodiments, the signal after being multiplied by the spread code is delayed, but in the spread spectrum communication system according to the third embodiment, A case where the spread code is delayed and multiplexed will be described.

FIG. 5 is a schematic block diagram showing a transmitter of a spread spectrum communication system according to the third embodiment of the present invention.

Referring to FIG. 5, the transmitter of the spread spectrum communication system according to the spread spectrum communication system according to the third embodiment includes a data generator 1, a differential encoder 3, an S / P converter 5, PN generator 7, local signal generator 9, delay devices 61, 63, 65, 67, 69, 71, 7
3, 75, multipliers 11, 13, 15, 17 and modulator 1
9, 21, 23, 25, multiplexer 35, frequency converter 3
7, a power amplifier 39 and a transmission antenna 41 are included. The same parts as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted as appropriate. Therefore, the characteristic part will be mainly described.

The delay devices 61 to 67 have parallel signals P1 to P1.
Delay P4 to generate delayed parallel signals D1-D4. On the other hand, the delay units 69 to 75 delay the spread code from the PN generator 7 and generate delay spread codes B1 to B4.
The delay time of the delay device 61 and the delay device 69, the delay device 63
And the delay time of the delay device 71, the delay time of the delay device 65 and the delay device 73, and the delay time of the delay device 67 and the delay device 75 are the same.

The multipliers 11 to 17 are provided for the delayed parallel signal D
1 to D4 and the delay spread code B1 from the delay units 69 to 75
~ B4 are multiplied to generate spread signals M1 to M4. Here, the delay times of the delay units 61 to 67 and the delay units 61 to 6
Since the delay times of the delay units 69 to 75 corresponding to 7 are the same, the timings of the delayed parallel signals D1 to D4 and the timings of the delay spread codes B1 to B4 match.

The delay times of the delay devices 69 to 75 are different from each other. The time difference between the delay times is an arbitrary time of 1 chip or more (first delay time setting method).

The delay time of the delay device having the shortest delay time among the delay devices 69 to 75 can be set to zero.
In this case, the parallel signal P corresponding to the delay device
The delay time of the delay device for delaying 1 to P4 is also 0. For example, when the delay time of the delay device 69 is 0, the delay time of the delay device 61 is 0. The relationship between the delay times is the same as described above. In addition, as an equivalent of this, it is also possible to eliminate the delay device for setting the delay time to zero.

The modulators 19 to 25 spread the spread signals M1 to M4.
Is modulated by using the local signal from the local signal generator 9 into an intermediate frequency signal (IF signal). The multiplexer 35 multiplexes the intermediate frequency signals from the modulators 19 to 25. The multiplexed signal is transmitted from the transmission antenna 41 as a transmission signal by the transmission antenna 41 via the frequency conversion unit 37 and the power amplification unit 39. The parallel signals P1 to P4 are baseband signals, and the delay devices 61 to 67 delay the baseband signals.

As described above, in the third embodiment, the delay time of the spread code and the corresponding parallel signals P1 to P4.
The same delay time is used. Therefore, the timing of the delay spread codes B1 to B4 and the delay parallel signals D1 to D
The timing of 4 does not shift due to the delay due to multiplexing, and the two timings match.

As a result, in the third embodiment,
It is possible to prevent deterioration of the correlation output on the receiving side, avoid the difficulty of demodulation, and perform multiplexed communication.

The time difference between the delay times of the delay devices 61 to 67 and the time difference between the delay times of the delay devices 69 to 75 is an arbitrary time of one chip or more (first delay time setting method).

As a result, in the third embodiment, the signal to be demodulated and the signal next to the signal do not overlap with each other, and the error rate characteristic can be improved. Further, the time difference between the delay times is not limited as in the conventional example (it is 1 chip or 2 chips in the past) and is set to an arbitrary time, so that the degree of freedom in designing the hardware, that is, the system is increased. be able to.

Further, since the parallel signals P1 to P4 which are basebands are delayed and multiplexed, the delay devices 61 to 61 are
Since 67 can be configured by a digital circuit, the transmitter can be downsized and highly integrated.

Further, as described in the first embodiment, the delay times of the delay units 63 to 67 can use the second delay time setting method. In other words, the delay times of the delay units 63 to 67 are set so that the time difference between the signals is constant and becomes an arbitrary time of one chip or more in the multiple multiplexed signals. In this case, the delay times of the delay units 69 to 75 corresponding to the delay units 61 to 67 are set in the same manner.

As a result, in the third embodiment, the number of delay paths on the receiving side is only one.
The circuit scale of the system is significantly reduced. Further, since the delay path is one regardless of the number of multiplexing, the circuit scale of the system does not increase even if the number of multiplexing increases.

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

Referring to FIG. 6, the transmitter of the spread spectrum communication system according to the fourth embodiment includes a data generator 1, a differential encoder 3, an S / P converter 5, a PN generator 7,
Latch units 81, 83, 85, 87, latch controller 89, delay devices 69, 71, 73, 75, multipliers 11, 1
3, 15, 17, modulators 19, 21, 23, 25, local signal generator 9, multiplexer 35, frequency converter 37, power amplifier 39, and transmission antenna 41. The same parts as those in FIG. 5 are designated by the same reference numerals, and the description thereof will be omitted as appropriate. The characteristic part will be mainly described.

In the third embodiment, the delay devices 61 to 67 are provided in order to match the timing of the delayed spread code with the timing of the parallel signals P1 to P4.
In the fourth embodiment, the latch units 81 to 87 and the latch controller 89 are provided in order to match the timing of the delayed spread code with the timing of the parallel signals P1 to P4.

The time difference between the delay times of the delay devices 69 to 75 is set to be an arbitrary time of one chip or more, and each delay time is different (first time).
Delay time setting method).

FIG. 7 is a diagram showing signals (data) in each node of the transmitter of FIG. The signals P1 to R
In FIG. 4, the time axis is shown in common. The horizontal direction of FIG. 7 is the time axis.

Referring to FIGS. 6 and 7, data A generated from data generator 1 is differentially encoded to obtain S / P.
The conversion unit 5 causes parallel signals (parallel data) P1 to
Converted to P4. In this case, four parallel signals P1
The timings of P4 to P4 are the same. Of the data A, D1, D5 and D9 are the parallel signal P1. Of the data A, D2, D6 and D10 are the parallel signal P2. Of data A, D3 and D7
And D11 are the parallel signal P3. Of the data A, D4, D8 and D12 are parallel signals P4.
It has become.

The spreading code generated from the PN generator 7 is
Delay spread codes B1 to B delayed by the delay units 69 to 75
It becomes 4. Here, the delay time of the delay device 69 is zero. As an equivalent of this, the delay device 69 can be omitted. As shown in FIG. 7, delay spread codes B2 to B4
Is delayed in accordance with the delay time of the delay devices 71 to 75, and therefore is deviated from the timing of the parallel signals P1 to P4. Since the delay spread code B1 is not delayed,
The timing is the same as that of the parallel signals P1 to P4. Note that one period of the spread code is T.

The latch controller 89 uses the PN generator 7
The latch signals (latch pulses) C1 to C4 are generated in response to the timing of the spread code generation from. The latch signals C1 to C4 have the same timing as the start chips of the corresponding delay spread codes B1 to B4.

By such latch signals C1 to C4,
The parallel signals P1 to P4 are latched by the latch units 81 to 87 and become the latch signals R1 to R4. Therefore, as shown in FIG. 7, the timings of the delay spread codes B1 to B4 and the latch signals R1 to R4 match.

The multipliers 11 to 17 have latch signals R1 to R, respectively.
4 is multiplied by the delay spread codes B1 to B4 to generate delay spread signals M1 to M4. The modulators 19 to 25 modulate the delay spread signals M1 to M4 using the local signal from the local signal generator 9 to generate an intermediate frequency signal (IF signal).
To The multiplexer 35 multiplexes these intermediate frequency signals. The combined signal passes through the frequency conversion unit 37 and the power amplification unit 39, and is transmitted as a transmission signal by the transmission antenna 4
It is sent from 1.

As described above, in the fourth embodiment, by providing the latch units 81 to 87 and the latch controller 89, the delay spread codes B1 to B4 and the parallel signal P are provided.
The timings of 1 to P4 (latch signals R1 to R4) are matched.

As a result, in the fourth embodiment, it is possible to prevent the deterioration of the correlation output on the receiving side, avoid the difficulty of demodulation, and perform multiplex communication.

Further, the time difference between the delay times of the delay devices 69 to 75 is set to an arbitrary time of 1 chip or more (first time).
Delay time setting method). Therefore, the signal to be demodulated and the signal that follows the signal do not overlap with each other, and the error rate characteristic can be improved. Further, unlike the conventional case, there is no limitation on the time difference between the delay times, and the delay time is set to an arbitrary time, so that the degree of freedom in designing the hardware, that is, the system can be increased.

Furthermore, the delay time of the delay devices 69 to 75 is
As with the first embodiment, the second delay time setting method can be used. That is, the delay times of the delay units 69 to 75 are set so that the time difference between the signals is constant and becomes an arbitrary time of one chip or more in a plurality of multiplexed signals. By doing so, since only one delay path is required on the receiving side, the circuit scale of the system is significantly reduced. Further, regardless of the number of multiplexing, the delay route is one, so that the circuit scale of the system does not increase even if the number of multiplexing increases.

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

Referring to FIG. 8, the receiver of the spread spectrum communication system according to the fifth embodiment has a receiving antenna 91, a frequency converting section 93, a distributor 95, a delay element 97,
99, 101, 103, frequency converters 105, 107,
109, 111, 113, correlators 115, 117,
119, 121, 123, differential unit 125, discrimination unit 127
And a local signal generator 129. The differential unit 125 and the determination unit 127 form a demodulation unit.

Here, the transmitter of FIG. 1 is used as the transmitter for the receiver of FIG. The receiving antenna 91 receives the transmission signal from the transmitter of FIG. Frequency converter 9
3 converts the received transmission signal into an intermediate frequency signal (IF signal). The distributor 95 distributes this intermediate frequency signal into a plurality of distribution signals Z1 to Z4. The number of distributions is one more than the number (multiplexed number) of data parallel-converted by the transmitter. Since the transmitter of FIG. 1 is used,
The number of distributions in FIG. 8 is five. The number of parallel conversions in FIG. 1 is four.

The distributed signals Z2 to Z5 are supplied to the delay elements 97 to 1 respectively.
Delayed by 03. The delay times of the delay elements 97 to 103 are set as follows, for example. The delay time of the delay elements 27 to 33 of the transmitter of FIG. 1, respectively tau _1, tau
Let ₂ , τ ₃ and τ ₄ . The magnitude relation of the delay time is as follows.

Τ ₁ > τ ₂ > τ ₃ > τ ₄ In such a case, the delay time of the delay element 97 of the receiver of FIG. 8 is τ ₂ −τ ₁ , and the delay time of the delay element 99 is τ ₃
−τ ₂ , the delay time of the delay element 101 is τ ₄ −τ ₃ .

In FIG. 1, the first data string (including four data) is parallel-converted, and then the next data string (including four data) is parallel-converted.
Here, the data string that comes first is called the previous data string, and the data string that comes next to the previous data string is called the latter data string. In FIG. 1, the time difference between the delay signal D4 based on the previous data sequence and the delay signal D1 based on the subsequent data sequence is the delay time in the delay element 103 in FIG. Hereinafter, description will be made assuming that the delay times of the delay elements 27 to 33 in FIG. 1 and the delay elements 97 to 103 in FIG. 8 are set as described above.

The frequency conversion section 105 uses the local signal from the local signal generator 129 to convert the distribution signal Z1 into a baseband signal. Frequency converter 107-
113 uses the local signal from the local signal generator 129 to convert the delayed distribution signals Z2 to Z5 into baseband signals. An unillustrated carrier synchronization circuit (phase detector) detects the carrier phase offset of the signal and controls the local signal generator 129 using the control signal to establish carrier synchronization. Therefore, the signals output from the frequency conversion units 105 to 113 are completely baseband signals.

The signals generated from the frequency conversion units 105 to 113 are input to the correlators (correlators) 115 to 123 which can be correlated with the spreading code used at the time of transmission, and output as the correlation signals A to E. A correlator
The correlation signal output from 115 to 123 may be referred to as a correlation output.

Differential section 125 performs differential decoding using correlation signals A to E. Specifically, the differential between the correlation signal A and the correlation signal B, the differential between the correlation signal B and the correlation signal C,
The differential between the correlation signal C and the correlation signal D and the differential between the correlation signal D and the correlation signal E are taken. The signal thus differentially decoded is input to the determination unit 127. The discrimination unit 127 discriminates data according to the data clock based on the differentially decoded signal, and outputs the data to the outside.

Differential decoding in the differential unit 125 will be described in detail. FIG. 9 is a diagram for explaining differential decoding in the differential unit 125 of FIG.

Referring to FIG. 9, FIG. 9A shows the correlation signal A of FIG. FIG. 9B shows the correlation signal B of FIG. FIG. 9C shows the correlation signal C of FIG. FIG.
(D) shows the correlation signal D of FIG. FIG. 9 (E) shows the correlation signal E of FIG.

Here, as described above, the delay time of the delay element 97 is τ ₂ −τ ₁ = τ _a, and the delay element 99 of FIG.
Is set to τ ₃ −τ ₂ = τ _b , and the delay element 101
Let the delay time of τ ₄ −τ ₃ = τ _c . In FIG. 1, the time difference between the delay signal D4 of the previous data string and the delay signal D1 of the subsequent data string is τ _d . That is, the delay time of the delay element 103 in FIG. 8 is set to τ _d . In FIG. 9, the delay time of the delay element 27 of FIG. 1 is set to 0. That is, this corresponds to the case where the delay element 27 is removed.

Referring to FIG. 9, signals a1 to a4 are
Based on the previous data sequence in FIG. 1, the signal b1
~ Signal b4 indicates a signal based on the subsequent data string. As shown in FIGS. 9A to 9E, with respect to the correlation signal A, the correlation signals B to E are times τ _a , τ _b , and
It can be seen that they are delayed by τ _c and τ _d .

Here, in the differential section 125 of FIG.
At point P1 in FIG. 9, the signal a2 in FIG.
Since the signal a1 of 1 is on the same time, the signal a2 and the signal a1 are differentiated. At the point P2, the signal a3 in FIG. 7A and the signal a2 in FIG. 3C are on the same time axis, and therefore the signal a3 and the signal a2 are differentiated. Similarly, the other signals are differential with respect to the correlation signal A shown in FIG. Data is demodulated by taking the differential in this way.

As described above, the transmitter shown in FIG. 1 is used in the spread spectrum communication system according to the fifth embodiment. As a result, in the spread spectrum communication system according to the fifth exemplary embodiment, the same effect as that of the first exemplary embodiment is obtained.

The spread spectrum communication system according to the fifth embodiment performs multiplexing by delaying the intermediate frequency signal on the transmitting side. Further, on the receiving side, a delay is performed using the intermediate frequency signal, and then,
The carrier is perfectly synchronized and processed into a baseband signal.

(Sixth Embodiment) The transmitter of the spread spectrum system according to the sixth embodiment uses the transmitter of FIG. In the fifth embodiment, the delay time difference between the delay element 29 and the delay element 27 in FIG. 1 is τ _a , the delay time difference between the delay element 31 and the delay element 29 is τ _b , and the delay element 33 is shown. the difference in the delay time of the delay element 31 and a tau _c, a time difference between the delay signal D1 of the data sequence after the delay signal D4 before the data string as tau _d, the magnitude of τ _a ~τ _d is Not specified. In the sixth embodiment, τ
The delay times of the delay elements 27 to 33 in FIG. 1 are set so that _a , τ _b , τ _c and τ _d all have the same time. That is, the second delay time setting method is used.

FIG. 10 is a schematic block diagram showing a receiver of a spread spectrum communication system according to the sixth embodiment of the present invention.

Referring to FIG. 10, the receiver of the spread spectrum communication system according to the sixth exemplary embodiment of the present invention includes a receiving antenna 91, a frequency converter 93, a distributor 95, a delay element 131, and a frequency converter 133. , 135, correlators 137 and 139, a differential unit 125, a determination unit 127, and a local signal generator 129. The same parts as those in FIG. 8 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

The distributor 95 distributes the intermediate frequency signal from the frequency converter 93 into two distribution signals ZZ1 and ZZ2. The distribution signal ZZ1 becomes the correlation signal AA via the frequency conversion unit 133 and the correlator 137, and the differential unit 12
5 is input. The distribution signal ZZ2 is supplied to the delay elements 131,
Through the frequency conversion unit 135 and the correlator 139,
The correlation signal BB is input to the differential unit 125.

The frequency converters 133 and 135 are the same as the frequency converters 105 to 113 in FIG. 8, and the local signal generator 129 and a carrier synchronization circuit (phase detector) (not shown) are used to completely remove the carrier. Synchronize,
The distribution signal ZZ1 and the delayed distribution signal ZZ2 are baseband signals. Correlators 137 and 139
Is similar to the correlators 115 to 123 in FIG.

The correlation signal AA is the same as the signal shown in FIG.
Is equivalent to τ_a, Τ_b, Τ_cAnd τ _dAre all the same
Is the case. This will be described in detail.

FIG. 11 is a diagram showing the correlation signal AA and the correlation signal BB of FIG. Referring to FIG. 11, signal a
_{1 to} a ₄ are multiplexed signals based on the previous data sequence in the transmitter of FIG. 1, and signals b _{1 to} b ₄ are multiplexed signals based on the subsequent data sequence. Here, adjacent signals have the same time interval τ _a . this is,
This is because the delay time of the transmitter of FIG. 1 is set by using the second delay time setting method as described at the beginning of the description of the sixth embodiment.

Here, FIG. 11 (AA) shows the correlation signal AA of FIG. 10, and FIG. 11 (BB) shows the correlation signal BB of FIG. Correlation signal BB lags correlation signal AA by time τ _a . That is, the delay time of the delay element 131 in FIG. 10 is τ _a . In this way, the delay time of the delay element 131 in FIG. 10 is set to be the same as the time difference between the adjacent signals in the plurality of multiplexed signals.

In the differential section 125 of FIG. 10, the signals of the correlation signal AA and the correlation signal BB on the same time axis are differentiated.

As described above, in the sixth embodiment, the transmitter of FIG. 1 which employs the second delay time setting method is used,
The delay time in the transmitter is set so that a plurality of signal sequences included in the correlation signal on the receiving side have the same time interval.

As a result, only one delay path is required for the receiver (four delay paths in FIG. 8), and the circuit scale of the receiver can be greatly reduced.

Further, in the sixth embodiment, since the transmitter of FIG. 1 is used, the same effect as that of the first embodiment can be obtained.

In the sixth embodiment, on the transmitting side,
The intermediate frequency signal is multiplexed by delaying it. Furthermore, on the receiving side, the intermediate frequency signal is delayed,
After that, the carrier is perfectly synchronized and the baseband signal is processed. Also, the transmitting side employs the second delay time setting method.

(Seventh Embodiment) The spread spectrum communication system according to the seventh embodiment uses the transmitter shown in FIG. 1 as in the fifth embodiment. The receiver is the receiver of FIG. 8 in which a frequency conversion unit for setting the base band is provided in the preceding stage of the distributor.

FIG. 12 is a schematic block diagram showing a receiver of a spread spectrum communication system according to the seventh embodiment of the present invention.

Referring to FIG. 12, the receiver of the spread spectrum communication system according to the seventh embodiment has a receiving antenna 91, frequency converters 93 and 141, a distributor 95, a local signal generator 129 and a delay element 97. , 99, 101,
103, correlators 115, 117, 119, 121,
123, a differential unit 125, and a discrimination unit 127 are included. Note that the same parts as those in FIG. 8 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. The characteristic part will be mainly described.

The intermediate frequency signal (IF signal) generated by the frequency conversion unit 93 is converted into a baseband signal by the frequency conversion unit 141. In this case, in FIG.
Similarly, a local signal generator 129 and a carrier synchronization circuit (phase detector) (not shown) are used to achieve complete carrier synchronization and a complete baseband signal.

The distributor 95 distributes the baseband signal from the frequency converter 141 into five signals, and distributes the signals Z1 to Z5.
Occurs. The delay elements 97-103 have the distribution signals Z2-
Delay Z5. The distributed signals Z2 to Z5 are baseband signals, which means that the baseband signals are delayed. The setting of the delay time is the same as in the fifth embodiment.

Distribution signal Z1 and delayed distribution signal Z
2 to Z5 are input to the correlators 115 to 123 and become the correlation signals AE. The differential unit 125 receives the correlation signals A to E.
Differential decoding is performed based on Then, the differentially decoded signal is output as data via the determination unit 127.

As described above, in the seventh embodiment, by providing the frequency conversion section 141 in the preceding stage of the distributor 95,
The processing is performed by delaying the distribution signal which is the base band.

As a result, in the seventh embodiment,
Compared to the fifth embodiment, the number of frequency conversion units can be reduced from five to one, and the circuit scale can be reduced. Note that in the seventh embodiment, even if the number of multiplexes increases,
The frequency converter for converting to a baseband signal is 1
It only needs one.

Further, since the baseband distribution signal is delayed, the delay elements 97 to 103 can be constituted by digital circuits, and the receiver can be made compact and highly integrated.

Further, in the seventh embodiment, since the transmitter of FIG. 1 is used, the same effect as that of the first embodiment can be obtained.

The delay elements 97 to 103 can be provided after the correlators 117 to 123. Also in this case, the same effect as described above can be obtained.

In the seventh embodiment, the transmission side performs multiplexing by delaying with an intermediate frequency signal.
Further, on the receiving side, the baseband signal perfectly carrier-synchronized is delayed to perform differential decoding (demodulation).

(Eighth Embodiment) The spread spectrum communication system according to the eighth embodiment uses the transmitter of FIG. 1 which employs the second delay time setting method. For this reason,
The setting of the delay time in the transmitter and the receiver is the same as that described in the sixth embodiment. The spread spectrum communication system receiver according to the eighth exemplary embodiment is provided with a frequency conversion unit for converting into a baseband signal of the receiver of FIG.

FIG. 13 is a schematic block diagram showing a receiver of a spread spectrum communication system according to the eighth embodiment. The same parts as those in FIG. 10 are designated by the same reference numerals, and the description thereof will be appropriately described. The characteristic part will be mainly described.

Referring to FIG. 13, the receiver of the spread spectrum communication system according to the eighth exemplary embodiment includes a receiving antenna 91, frequency converters 93 and 141, a local signal generator 129, a distributor 95, and a delay element 131. , Correlator 1
37, 139, a differential unit 125, and a discrimination unit 127.

The frequency conversion unit 141 has a frequency conversion unit 93.
The intermediate frequency signal from 1 is converted into a baseband signal by using the local signal (carrier) from the local signal generator 129. In this case, although not shown in the figure, carrier synchronization is perfectly achieved by using a carrier synchronizing circuit.

The distributor 95 distributes the baseband signal from the frequency conversion unit 141 into two signals and distributes them to the distribution signals ZZ1 and Z2.
Z2 is generated. The correlator 137 outputs the distribution signal ZZ1.
By using the spread code used at the time of transmission to generate a correlation signal AA. The distribution signal ZZ2 is output to the delay element 131.
Is input to the correlator 139 via. The correlator 139 uses the delayed distribution signal ZZ2 to perform correlation with the spreading code used at the time of transmission and generates a correlation signal BB. The differential unit 125 performs differential decoding using the correlation signals AA and BB. The differentially decoded signal is used for the discriminating unit 1
It is output as data via 27.

The delay time of the delay element 131 is as shown in FIG.
Similar to the delay time of the delay element 131 of 0, the delay time is set to be equal to the time difference between adjacent signals that are delayed and multiplexed on the transmission side.

As described above, in the eighth embodiment, the frequency conversion unit for converting into the baseband signal is provided in the preceding stage of the distributor to delay the processing of the baseband signal. Are doing.

As a result, in the eighth embodiment, as shown in FIG.
Compared with the receiver of No. 2, the number of frequency converters can be reduced from two to one, and the delay element 131 can be configured by a digital circuit, so that the receiver can be downsized.

Further, in the eighth embodiment, as in the sixth embodiment, the delay time is set in the transmitter by using the second delay time setting method. That is, the delay time of the receiver is set so that the time difference between consecutive adjacent signals becomes constant.

As a result, in the eighth embodiment, as shown in FIG.
As shown in FIG. 3, the receiver can have only one delay path, and the circuit scale of the receiver can be reduced. Further, since the number of delay paths of the receiver is one regardless of the number of multiplexing, the circuit scale does not increase even if the number of multiplexing increases.

Furthermore, in the eighth embodiment, since the transmitter of FIG. 1 is used, the same effect as that of the first embodiment can be obtained.

In the eighth embodiment, the transmitting side delays the intermediate frequency signal to perform multiplexing.
Further, on the receiving side, the baseband signal perfectly carrier-synchronized is delayed to perform differential decoding (demodulation). Further, the transmitting side uses the second delay time setting method.

(Ninth Embodiment) A spread spectrum communication system according to the ninth embodiment uses the transmitter shown in FIG. Further, in the ninth embodiment, the correlator of the receiver shown in FIG. 12 is provided in the preceding stage of the distributor.

FIG. 14 is a schematic block diagram showing a receiver of a spread spectrum communication system according to the ninth embodiment of the present invention. The same parts as those in FIG. 12 are designated by the same reference numerals, and the description thereof will be appropriately described. The characteristic part will be mainly described.

Referring to FIG. 14, the receiver of the spread spectrum communication system according to the ninth exemplary embodiment includes a receiving antenna 91, frequency conversion units 93 and 141, a local signal generator 129, a correlator 151, a distributor 95, Delay element 9
7, 99, 101, 103, differential unit 125, discrimination unit 12
Including 7.

The correlator 151 includes the frequency converter 141.
Using the baseband signal from, the correlation is obtained with the spreading code used during transmission, and the correlation signal is output. Distributor 95
At the transmitting side, distributes the correlation signal from the correlator 151 by one more than the number of parallel signals.
1 to Z5 are generated. The differential unit 125 receives the distribution signal Z1 and the distribution signal Z delayed by the delay elements 97 to 103.
Receive 2 to Z5.

Differential section 125 performs differential decoding using distribution signal Z1 and delayed distribution signals Z2-Z5. The differentially decoded signal is output as data via the determination unit 127.

As described above, in the ninth embodiment, the processing is performed by providing the correlator 151 before the distributor 95.

As a result, in the ninth embodiment, as shown in FIG.
The number of correlators can be reduced from five to one, and the circuit scale of the receiver can be reduced as compared with the receiver of.

Further, in the ninth embodiment, the receiver of FIG. 1 is used, so that the same effect as that of the first embodiment is obtained.

Further, since the delay is realized in the base band in the receiver, a digital delay element can be adopted as the delay element, and the receiver can be miniaturized and highly integrated.

In the ninth embodiment, on the transmitting side,
Multiplexing is performed by delaying the intermediate frequency signal. Furthermore, the receiver performs differential decoding (demodulation) by processing a baseband signal that is completely carrier-synchronized.

(Tenth Embodiment) The spread spectrum communication system according to the tenth embodiment uses the transmitter of FIG. 1 which employs the second delay time setting method. Therefore, the delay time is set in the transmitter and the receiver as in the sixth embodiment. Moreover, in the receiver of the tenth embodiment, the correlator in the receiver of FIG. 13 is provided in the preceding stage of the distributor.

FIG. 15 is a schematic block diagram showing a receiver of a spread spectrum communication system according to the tenth embodiment.

Referring to FIG. 15, the receiver of the spread spectrum communication system according to the tenth embodiment has a receiving antenna 91, frequency converters 93 and 141, a local signal generator 129, a correlator 151, a distributor 95, and The delay element 131, the differential unit 125, and the determination unit 127 are included. The same parts as those in FIG. 13 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. The characteristic part will be mainly described.

Referring to FIG. 15, correlator 151 has
Using the baseband signal from the frequency converter 141, the spread code at the time of transmission is used for correlation. Distributor 65
Divides the baseband correlation signal from the correlator 151 into two to generate distribution signals ZZ1 and ZZ2. The differential unit 125 includes the distribution signal ZZ1 and the delay element 1
31 receives the delayed distribution signal ZZ2. The signal differentially decoded by the differential unit 125 is determined by the determination unit 127.
Is output as data.

The distribution signals ZZ1 and ZZ2 are shown in FIG.
Corresponding to the correlation signals AA, BB of FIG.

As described above, in the tenth embodiment,
By providing the correlator 151 in the preceding stage of the distributor 95, processing is performed by delaying the correlation signal which is the base band.

As a result, in the tenth embodiment, the eighth
In comparison with the receiver of FIG.
And one delay element 131
Since it can be configured with a digital circuit, the circuit scale can be reduced.

Furthermore, in the tenth embodiment, the transmitter of FIG. 1 which employs the second delay time setting method is used, and the delay time is set in the transmitter and the receiver in the sixth embodiment. Since it is the same as that of the first embodiment, the same effect as that of the first and sixth embodiments can be obtained.

In the tenth embodiment, the transmission side performs multiplexing by delaying the intermediate frequency signal. Further, on the receiving side, processing is performed by delaying a baseband signal that is completely carrier synchronized. Also, the transmitting side employs the second delay time setting method.

(Eleventh Embodiment) The spread spectrum communication system according to the eleventh embodiment uses the transmitter shown in FIG.

FIG. 16 is a schematic block diagram showing a receiver of a spread spectrum communication system according to the eleventh embodiment of the present invention. Note that the same parts as those in FIG. 8 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. The characteristic part will be mainly described.

Referring to FIG. 16, the receiver of the spread spectrum communication system according to the eleventh embodiment has a receiving antenna 91, a frequency converter 93, a distributor 95, and a delay element 9.
7,99,101,103, distributors 161,163,1
65, 167, 169, frequency converters 171, 173
175,177,178,181,183,185,1
87,189, correlators 191,193,195,1
97, 199, 201, 203, 205, 207, 20
9, a differential unit 125 and a determination unit 127 are included.

The distributor 95 distributes the intermediate frequency signal from the frequency converter 93 by one more than the number of parallel signals in the transmitter, and generates distribution signals Z1 to Z5. The distribution signal Z1 and the distribution signals Z2 to Z5 delayed by the delay elements 97 to 103 are distributed to the distributors 161 to 169.
Is input to and further divided into two.

The signals generated from the distributors 161 to 169 are subjected to the local signals from the local signal generator 129, that is, the sine component and the cos component having substantially the same frequency, to the transmission side frequency signal by the frequency conversion units 171 to 189. By using an in-phase signal (hereinafter referred to as "I signal") of almost baseband (hereinafter referred to as "pseudo baseband")
And a quadrature signal (hereinafter referred to as “Q signal”). The I signal and the Q signal generated from the frequency conversion units 171 to 189 are input to the correlators 191 to 209.

Correlators 191 to 209 use the I signal and Q signal to perform correlation with the spreading code used at the time of transmission and generate a correlation signal. The differential unit 125 performs differential decoding using the correlation signals from the correlators 191 to 209. The differentially decoded signal is output as data via the determination unit 127.

The operation of the differential section 125 is the same as that of the differential section 125 of FIG. 8, but different parts will be described below.

Since the signal input thereto is not the baseband but the pseudo baseband, the differential section 125 differentially demodulates from the change in the phase angle. Therefore, although not shown, the differential section 125 includes an I signal and a Q signal.
It has means for detecting the phase from the correlation signal of the signal. explain in detail.

FIG. 17 is a diagram for explaining differential decoding in the differential unit 125 of FIG.

FIG. 17A shows the differential in the differential section 125 in the fifth to tenth embodiments. FIG.
16B is a diagram for explaining differential in the differential unit 125 in FIG. 16.

In the fifth to tenth embodiments, the differential decoding is performed using the completely carrier-synchronized baseband signal (synchronous demodulation method). In this case, as shown in FIG. 17A (in the case of DBPSK),
A correlation signal is output on the I-axis according to the content of the data. (Arrow S1).

Therefore, the phase difference is 0 ° or 180 °
The Q-axis (I = 0) is the criterion for determining whether or not.
That is, when the phase angle is θ, the area A1 (90
There is a signal in ° ≤ θ ≤ -90 °, or in the B1 area (-9
It is determined whether the phase difference is 0 ° or 180 ° depending on whether or not there is a signal in 0 ° ≦ θ ≦ 90 °).

The area A1 is a judgment area with a phase difference of 0 °.
The area B1 is a judgment area with a phase difference of 180 °.

In the present embodiment, differential decoding (demodulation) is performed using a pseudo baseband signal (asynchronous demodulation method). In such an asynchronous demodulation method, the phase of the signal output according to the content of the data is unknown, and as shown in FIG.
Take an arbitrary phase (arrow S2). The phase angle when such an arbitrary phase is taken is θ ₀ . Therefore, as shown in FIG. 17B, the determination of whether the phase difference is 0 ° or 180 ° is made in the area A2 (90 ° + θ ₀ ≦ θ ≦ −90 ° + θ).
₀ ) or there is a signal in the area of B2 (-90 ° + θ ₀ ≦ θ
It depends on whether or not there is a signal at ≦ 90 ° + θ ₀ ). That is, the judgment is made based on the axis C shown by the broken line.

The area A2 is a judgment area with a phase difference of 0 °.
The area B2 is a judgment area with a phase difference of 180 °.

In this way, the differential decoding unit 125 demodulates the data (0, 1) from the change in the phase difference.
That is, the differential between the phase obtained from the correlation signal based on the I signal and the correlation signal based on the Q signal without delay and the phase of the correlation signal based on the I signal and the correlation signal based on the Q signal at each delay timing By taking it, the data is demodulated. The Q axis shows the amplitude of the sine carrier, and the I axis shows the amplitude of the cosine carrier.

As described above, in the eleventh embodiment,
Differential decoding (demodulation) is performed using a pseudo baseband signal that is not a complete baseband signal.

As a result, in the eleventh embodiment, since differential decoding (demodulation) is possible without carrier synchronization, a carrier synchronization circuit (phase detector) is not required and a baseband signal is obtained. Thus, the circuit scale can be reduced as compared with a receiver when differential decoding (demodulation) is performed in. Further, since the time until carrier synchronization becomes 0, the initial operation becomes faster, and the throughput can be improved in packet communication or the like in which the communication time is short.

Furthermore, since the transmitter of FIG. 1 is used in the eleventh embodiment, the same effect as that of the first embodiment can be obtained. In the eleventh embodiment, the transmission side performs multiplexing by delaying the intermediate frequency signal. Further, on the receiving side, an asynchronous demodulation method (a method of demodulating using a pseudo baseband signal that is not completely carrier synchronized) is used to perform processing by delaying the intermediate frequency signal.

(Twelfth Embodiment) The spread spectrum communication system according to the twelfth embodiment uses the transmitter of FIG. 1 which employs the second delay time setting method. Therefore, the delay times at the transmitter and the receiver are the same as in the sixth embodiment.

FIG. 18 is a schematic block diagram showing a receiver of a spread spectrum communication system according to the twelfth embodiment of the present invention. The same parts as those in FIG. 10 are designated by the same reference numerals, and the description thereof will be omitted as appropriate. The characteristic part will be mainly described.

Referring to FIG. 18, the receiver of the spread spectrum communication system according to the twelfth embodiment has a receiving antenna 91, a frequency converter 93, a distributor 95, and a delay element 1.
31, distributors 213 and 215, frequency converters 217 and 2
19,221,223, correlators 225,227,2
29, 231, a differential unit 125, and a discrimination unit 127 are included.

Distribution signal ZZ1 and distribution signal ZZ2 delayed by delay element 131 are distributed to distributors 213 and 215.
Is input to The frequency conversion units 217 to 223 convert the signals from the distributors 213 and 215 into the local signal generator 12
The local signal from 9, that is, the sin component and the cos component having substantially the same frequency as the transmission side frequency are used to convert into the I signal and the Q signal which are pseudo basebands (almost baseband). Correlators 225 to 231 have Q
The signal and the I signal are used to perform correlation with the spread code at the time of transmission to generate a correlation signal. The differential unit 125 performs differential decoding using the correlation signals from the correlators 225 to 231. The differentially decoded signal is discriminated by the discrimination unit 127.
Is output as data via. The differential unit 12
The operation of No. 5 is similar to that of the differential unit 125 of FIG.

As described above, in the twelfth embodiment,
Differential decoding (demodulation) is performed using a pseudo baseband signal (a method of demodulating by a quasi-synchronous detection method, that is, an asynchronous demodulation method). As a result, in the twelfth embodiment, differential decoding (demodulation) is performed without complete carrier synchronization.
Therefore, the carrier synchronization circuit (phase detector) is not required, and the circuit scale can be reduced as compared with the case where differential decoding is performed with a complete baseband signal. Furthermore, the time until carrier synchronization becomes 0, and the initial operation becomes faster, so in packet communication etc. where communication time is short,
Throughput can be improved.

Further, since the transmitter of FIG. 1 employs the second delay time setting method, the delay time is set so that the time difference between consecutive signals becomes constant as in the sixth embodiment. It is set. As a result, in the twelfth embodiment, the number of delay paths can be reduced to one on the transmitting side, and the circuit scale of the system can be greatly reduced. Further, regardless of the number of multiplexes, only one delay path is required, so the circuit scale does not increase even if the number of multiplexes increases.

Furthermore, in the twelfth embodiment, the transmitter of FIG. 1 is used, so that the same effect as that of the first embodiment can be obtained.

In the twelfth embodiment, the transmission side performs multiplexing by delaying the intermediate frequency signal. Furthermore, on the receiving side, the intermediate frequency signal is delayed,
Differential decoding (demodulation) is performed using a pseudo baseband signal that is not completely carrier synchronized. further,
On the transmission side, the second delay time setting method is adopted.

(Thirteenth Embodiment) In a spread spectrum communication system according to a thirteenth embodiment, a frequency converter for converting to the pseudo baseband shown in FIG. 16 is provided in the pseudo base before the delay element and the distributor. It is configured to delay the band signal.

The transmitter shown in FIG. 1 is used as the transmitter.
FIG. 19 is a schematic block diagram showing the receiver of the spread spectrum communication system according to the thirteenth embodiment of the present invention.
The same parts as those in FIG. 16 are designated by the same reference numerals, and the description thereof will be omitted as appropriate. The characteristic part will be mainly described.

Referring to FIG. 19, the receiver of the spread spectrum communication system according to the thirteenth embodiment has a receiving antenna 91, a frequency converter 93, a distributor 95, frequency converters 241, 243, distributors 245, 245. 247, delay element 2
49, 251, 253, 255, 257, 259, 26
1, 263, correlators 191, 193, 195, 19
7,199,201,203,205,207,20
9, a differential unit 125 and a determination unit 127 are included.

The divider 95 divides the intermediate frequency signal into two to generate a divided signal. One of the distribution signals is a local signal from the local signal generator 129, that is,
Using the sin component of almost the same frequency for the transmission side frequency,
The frequency converter 241 converts the pseudo baseband signal (substantially baseband signal) into a Q signal (orthogonal signal). The distributor 245 distributes the Q signal from the frequency converter 241 into five and generates a distributed signal. Note that the number of distributions is one more than the number of parallel signals in the transmitter of FIG.

One of the distribution signals from distributor 240 is input to correlator 191 as it is, and the other four distribution signals are input to correlators 193 to 193 through delay elements 249 to 255.
It is input to 199. The correlation signals from the correlators 191 to 199 are input to the differential unit 125.

On the other hand, the other distribution signal from the distributor 95 uses the local signal from the local signal generator 129, that is, the cos component having substantially the same frequency as the transmission side frequency, and is transmitted to the pseudo base by the frequency conversion unit 243. It is converted to a band I signal (in-phase signal). After that,
The same operation as the Q signal from the frequency conversion unit 241 is performed.

The differential section 125 includes correlators 191 to 20.
Differential decoding is performed using the correlation signal from 9 and the differentially decoded signal is output as data via the determination unit 127.

The delay times of the delay elements 249 to 255 are τa to τd, and the delay times of the delay elements 257 to 263 are τa to τd, respectively, which are the same as the delay elements 97 to 103 in FIG. It is set in the same manner as in FIG. The differential unit 125 is similar to the differential unit 125 of FIG.

As described above, in the thirteenth embodiment,
By providing a frequency conversion unit that converts the intermediate frequency signal into a pseudo baseband signal in the preceding stage of the delay element, processing is performed by delaying the pseudo baseband signal.

As a result, in the thirteenth embodiment, FIG.
Compared to the receiver of 6, the number of delay elements is increased from 4 to 8, but the frequency conversion unit for converting to a pseudo baseband signal can be significantly reduced from 10 to 2.
The circuit scale can be reduced.

Furthermore, since the pseudo baseband signal is delayed, the delay element can be configured by a digital circuit, and the receiver can be downsized and highly integrated.

Furthermore, since the transmitter of FIG. 1 is used, the same effect as that of the first embodiment can be obtained.

Further, as in the eleventh embodiment, since the processing is performed by the pseudo baseband signal which is not completely carrier-synchronized, the carrier synchronization circuit (phase detector) is not necessary and the complete synchronization is achieved. The circuit scale can be reduced as compared with the case of processing with a baseband signal. Furthermore, since the time until carrier synchronization becomes 0, the initial operation becomes faster, and the throughput can be improved in packet communication with a short communication time.

In the thirteenth embodiment, the transmitting side performs multiplexing by delaying with the intermediate frequency signal. Further, on the receiving side, a pseudo baseband signal that is not completely carrier-synchronized is delayed and then differential decoding (demodulation) is performed.

(Fourteenth Embodiment) The spread spectrum communication system according to the fourteenth embodiment uses the transmitter of FIG. 1 which employs the second delay time setting method. Therefore, the setting of the delay time in the transmitter and the receiver is the same as that in the sixth embodiment. In the fourteenth embodiment, a frequency conversion unit for converting to the pseudo baseband shown in FIG. 18 is provided in the preceding stage of the delay element, and the processing is performed by delaying the pseudo baseband signal.

FIG. 20 is a schematic block diagram showing a receiver of a spread spectrum communication system according to the 14th embodiment of the present invention. The same parts as those in FIG. 18 are designated by the same reference numerals, and the description thereof will be omitted as appropriate. The characteristic part will be mainly described.

Referring to FIG. 20, the receiver of the spread spectrum communication system according to the fourteenth embodiment has a receiving antenna 91, a frequency conversion unit 93, a distributor 95, frequency conversion units 291, 293, a distributor 213, and the like. 215, a local signal generator 129, delay elements 229 and 301, correlators 225, 227, 229 and 231, a differential section 125 and a discrimination section 127.

Referring to FIG. 20, distributed signal ZZ1 is converted by frequency converter 291 into a Q signal (orthogonal signal) which is a pseudo baseband using the sin component from local signal generator 129. The distributor 213 distributes the Q signal into two. One distribution signal from the distributor 213 is input to the correlator 225 and output as a correlation signal. The other distribution signal from the distributor 213 is input to the correlator 227 via the delay element 229 and output as a correlation signal.

The distribution signal ZZ2 is converted by the frequency conversion unit 293 into an I signal (in-phase signal) which is a pseudo base band using the cos component from the local signal generator 129. The subsequent processing is the same as the above-described processing of the Q signal. The frequency conversion unit 291 is similar to the frequency conversion unit 217 of FIG. 18, and the frequency conversion unit 293 is
The frequency conversion unit 219 of FIG.
Reference numerals 99 and 301 are similar to the delay element 131 in FIG. Therefore, the delay time of the delay elements 299 and 301 is the difference between the delay times that are closest to each other in the transmitter.

As described above, in the fourteenth embodiment,
By providing a frequency conversion unit that converts a signal in the pseudo baseband in the preceding stage of the delay element, processing is performed by delaying the signal in the pseudo baseband.

As a result, in the fourteenth embodiment, FIG.
Compared with the receiver of No. 8, the number of frequency converters for converting to a pseudo baseband signal can be changed from four to two, and the circuit scale of the receiver can be reduced.

Furthermore, in the fourteenth embodiment, the second delay time setting method is adopted, and the delay time is set by the transmitter so that the time intervals between consecutive signals are the same, Similar to the sixth embodiment, only one delay path is required on the receiver side, and the circuit scale can be significantly reduced. Moreover, since the number of delay paths is one regardless of the number of multiplexing, the circuit scale does not increase even if the number of multiplexing increases.

Further, since the pseudo baseband signal is delayed, the delay element can be constructed by a digital circuit, and the receiver can be miniaturized and highly integrated.

Further, in the fourteenth embodiment, since the pseudo baseband signal is delayed and the differential decoding (demodulation) is performed, the carrier synchronizing circuit (phase detector) is not required, and the complete decoding is completed. The circuit scale can be reduced as compared with the case of processing with a baseband signal. Further, since the time until carrier synchronization becomes 0, the initial operation becomes faster, and the throughput can be improved in packet communication or the like with a short communication time.

In the fourteenth embodiment, the transmitter carries out multiplexing by delaying with an intermediate frequency signal. Further, on the receiving side, differential decoding (demodulation) is performed using a pseudo baseband signal that is not completely carrier synchronized. Also, the second delay time setting method is used.

(Fifteenth Embodiment) In a spread spectrum communication system according to a fifteenth embodiment, the correlator shown in FIG. 19 is provided in front of the distributor at the subsequent stage. Furthermore, the transmitter uses the transmitter of FIG.

FIG. 21 is a schematic block diagram showing a receiver of a spread spectrum communication system according to the 15th embodiment. The same parts as those in FIG. 19 are designated by the same reference numerals, and the description thereof will be omitted as appropriate. The characteristic part will be mainly described.

Referring to FIG. 21, the receiver of the spread spectrum communication system according to the fifteenth embodiment has a receiving antenna 91, a frequency converter 93, a distributor 95, frequency converters 241, 243, correlators 311 and 313. , Distributors 245, 247, local signal generator 129, delay elements 249, 251, 253, 255, 257, 259, 2
61,263, the differential part 125, and the discrimination | determination part 127 are included.

The correlator 311 has a frequency converter 241.
Using the pseudo baseband Q signal from, the correlation signal is generated by the spreading code used at the time of transmission and a correlation signal is generated. The distributor 245 distributes the correlation signal from the correlator 311 into five and generates a distribution signal. One of the distribution signals from the distributor 245 is input to the differential unit 125 as it is, and the other four signals are input to the differential unit 1 via the delay elements 249 to 255.
25.

The pseudo baseband I signal generated from the frequency conversion section 243 is processed in the same manner as the Q signal. Differential section 125 receives the two distributed signals from distributors 245 and 247 and the eight signals from delay elements 249 to 263, and performs differential decoding. The differentially decoded signal is output as data via the determination unit 127.

As described above, in the fifteenth embodiment,
The processing is performed by providing the correlator in the preceding stage of the distributor for distributing the pseudo baseband signal.

As a result, in the fifteenth embodiment, FIG.
Compared with the 9 receivers, the 10 correlators can be reduced to 2 and the circuit scale can be reduced.

Furthermore, since the transmitter of FIG. 1 is used,
The same effects as those of the first embodiment can be obtained.

Further, since the pseudo baseband signal is delayed, the delay element can be constructed by a digital circuit, and the receiver can be miniaturized and highly integrated.

Further, since the differential decoding (demodulation) is performed by using the signal of the pseudo baseband which is not completely carrier-synchronized, the carrier synchronization circuit (phase detector) is unnecessary and the base is completely The circuit scale can be reduced as compared with the case where processing is performed using band signals. Further, since the time until carrier synchronization becomes 0, the initial operation becomes faster, and the throughput can be improved in packet communication or the like in which the communication time is short.

In the fifteenth embodiment, the transmitting side performs multiplexing by delaying the intermediate frequency signal. Further, on the receiving side, processing is performed using a pseudo baseband signal that is not completely carrier synchronized.

(Sixteenth Embodiment) In the spread spectrum communication system according to the sixteenth embodiment, the correlator shown in FIG. 20 is provided in the preceding stage of the distributor for distributing the pseudo baseband signal. As the transmitter, the transmitter of FIG. 1 that employs the second delay time setting method is used.

FIG. 22 is a schematic block diagram showing a receiver of a spread spectrum communication system according to the 16th embodiment of the present invention. The same parts as those in FIG. 20 are designated by the same reference numerals, and the description thereof will be omitted as appropriate. The characteristic part will be mainly described.

Referring to FIG. 22, the receiver of the spread spectrum communication system according to the sixteenth embodiment has a receiving antenna 91, a frequency converter 93, a distributor 95, frequency converters 291, 293, correlators 311 and 313. , Distributors 213 and 215, a local signal generator 129, delay elements 299 and 301, a differential unit 125 and a discriminating unit 127.

The correlator 311 has a frequency converter 291.
Using the Q signal, which is the pseudo baseband from, the correlation signal is generated with the spreading code used on the transmission side and a correlation signal is generated. The distributor 213 distributes the correlation signal from the correlator 311 into two to generate a distribution signal. One distribution signal from the distributor 213 is input to the differential unit 125. Distributor 213
The other distributed signal from is input to the differential unit 125 via the delay element 299.

The I signal which is the pseudo baseband from the frequency conversion unit 293 is processed in the same manner as the Q signal. The differential unit 125 receives the two distribution signals from the distributors 213 and 215 and the two delayed distribution signals from the delay elements 299 and 301. The differential unit 125 performs differential decoding based on these signals. The differentially decoded signal is output as data via the determination unit 127.

As described above, in the sixteenth embodiment,
The processing is performed by providing a correlator in the preceding stage of the distributor for distributing the pseudo baseband signal.

As a result, in the sixteenth embodiment, FIG.
Compared with the receiver of 0, four correlators can be reduced to two and the circuit scale can be reduced.

Furthermore, in the sixteenth embodiment, since the transmitter of FIG. 1 is used, the same effect as that of the first embodiment can be obtained.

Furthermore, since the receiver side performs differential decoding (demodulation) by processing the pseudo baseband signal, the carrier synchronization circuit (phase detector) is not required and a complete baseband signal is used. It is possible to reduce the circuit scale as compared with the case where the processing is performed by the above method. Further, since the time until synchronization is unnecessary, the throughput can be improved by eliminating the synchronization time in packet communication or the like having a short communication time.

Furthermore, since the pseudo baseband signal is delayed, the delay element can be constructed by a digital circuit, and the receiver can be miniaturized and highly integrated.

Further, the second delay time setting method is adopted, and as in the sixth embodiment, the delay time in the transmitter is set so that the time differences between consecutive signals are all the same. Therefore, the delay path on the receiving side is 1
Therefore, the circuit scale can be significantly reduced.
Further, since there is only one delay path regardless of the number of multiplexing, the circuit scale does not increase even if the number of multiplexing increases.

In the sixteenth embodiment, the transmitting side performs multiplexing by delaying the intermediate frequency signal. Further, on the receiving side, the subsequent processing is performed by delaying the pseudo baseband signal that is not completely carrier synchronized. Also, the transmitting side employs the second delay time setting method.

(Seventeenth Embodiment) In a spread spectrum communication system according to a seventeenth embodiment, the transmitter of FIG. 4 and the receiver of FIG. 12 constitute a spread spectrum communication system. The features will be described. In the transmitter, delay is performed after spreading the plurality of parallel signals P1 to P4 with a spreading code. Further, the time difference between the delay times is set to an arbitrary time of 1 chip or more (first delay time setting method). Also, multiplexing is performed by delaying the baseband signal.

The receiver performs differential decoding (demodulation) by delaying the baseband signal perfectly carrier-synchronized.
Are doing.

Because of the configuration and characteristics as described above, the spread spectrum communication system according to the seventeenth embodiment has the same effects as those of the second and seventh embodiments.

(Eighteenth Embodiment) In a spread spectrum communication system according to an eighteenth embodiment, a spread spectrum communication system is configured by using the transmitter of FIG. 4 and the receiver of FIG. The features will be described. In the transmitter, delay is performed after spreading the plurality of parallel signals P1 to P4 with a spreading code. Furthermore, the time difference between the delay times is fixed and is set to an arbitrary time of one chip or more (second delay time setting method). Also, multiplexing is performed by delaying the baseband signal.

The receiver carries out differential decoding (demodulation) by delaying a baseband signal in which carrier synchronization is perfectly obtained.

With the above-mentioned configuration and characteristics, the spread spectrum communication system according to the eighteenth embodiment has the same effects as those of the second and eighth embodiments.

(Nineteenth Embodiment) In a spread spectrum communication system according to a nineteenth embodiment, the spread spectrum communication system is configured by using the transmitter of FIG. 4 and the receiver of FIG. The features will be described. In the transmitter, delay is performed after spreading the plurality of parallel signals P1 to P4 with a spreading code. Furthermore, the time difference between the delay times is set to an arbitrary time of 1 chip or more (first
Delay time setting method). Also, multiplexing is performed by delaying the baseband signal.

The receiver performs differential decoding (demodulation) by processing a baseband signal perfectly carrier synchronized.

Because of the configuration and characteristics as described above, the spread spectrum communication system according to the nineteenth embodiment has the same effects as those of the second and ninth embodiments.

(Twentieth Embodiment) In a spread spectrum communication system according to a twentieth embodiment, a spread spectrum communication system is configured by using the transmitter of FIG. 4 and the receiver of FIG. The features will be described. In the transmitter, delay is performed after spreading the plurality of parallel signals P1 to P4 with a spreading code. Furthermore, the time difference between the delay times is fixed and is set to an arbitrary time of one chip or more (second delay time setting method). Also, multiplexing is performed by delaying the baseband signal.

The receiver performs processing by delaying a baseband signal that is completely carrier synchronized.

Because of the configuration and characteristics as described above, the spread spectrum communication system according to the twentieth embodiment has the same effects as those of the second and tenth embodiments.

(Twenty-first Embodiment) In a spread spectrum communication system according to a twenty-first embodiment, a spread spectrum communication system is configured by using the transmitter of FIG. 4 and the receiver of FIG. The features will be described. In the transmitter, delay is performed after spreading the plurality of parallel signals P1 to P4 with a spreading code. Furthermore, the time difference between the delay times is set to an arbitrary time of 1 chip or more (first
Delay time setting method). Also, multiplexing is performed by delaying the baseband signal.

The receiver delays a pseudo baseband signal which is not completely carrier-synchronized, and then performs differential decoding (demodulation).

Because of the configuration and characteristics as described above, the spread spectrum communication system according to the twenty-first embodiment has the same effects as those of the second and thirteenth embodiments.

(Twenty-Second Embodiment) In a spread spectrum communication system according to a twenty-second embodiment, the spread spectrum communication system is configured by using the transmitter of FIG. 4 and the receiver of FIG. The features will be described. In the transmitter, delay is performed after spreading the plurality of parallel signals P1 to P4 with a spreading code. Furthermore, the time difference between the delay times is fixed and is set to an arbitrary time of one chip or more (second delay time setting method). Also, multiplexing is performed by delaying the baseband signal.

The receiver performs differential decoding (demodulation) with a pseudo-base signal that is not completely carrier-synchronized.

Because of the configuration and characteristics as described above, the spread spectrum communication system according to the twenty-second embodiment has the same effects as those of the second and fourteenth embodiments.

(Twenty-third Embodiment) A spread spectrum communication system according to a twenty-third embodiment is a spread spectrum communication system using the transmitter of FIG. 4 and the receiver of FIG. The features will be described. In the transmitter, delay is performed after spreading the plurality of parallel signals P1 to P4 with a spreading code. Furthermore, the time difference between the delay times is set to an arbitrary time of 1 chip or more (first
Delay time setting method). Also, multiplexing is performed by delaying the baseband signal.

The receiver delays a pseudo baseband signal that is not completely carrier-synchronized, and then performs differential decoding (demodulation). Since the spread spectrum communication system according to the twenty-third embodiment has the configuration and characteristics as described above, the second embodiment and the fifteenth embodiment
The same effect as that of the embodiment is obtained.

(Twenty-fourth Embodiment) In a spread spectrum communication system according to a twenty-fourth embodiment, a spread spectrum communication system is configured by using the transmitter of FIG. 4 and the receiver of FIG. The features will be described. In the transmitter, delay is performed after spreading the plurality of parallel signals P1 to P4 with a spreading code. Furthermore, the time difference between the delay times is fixed and is set to an arbitrary time of one chip or more (second delay time setting method). Also, multiplexing is performed by delaying the baseband signal.

The receiver carries out the subsequent processing by delaying the pseudo baseband signal which is not completely carrier-synchronized. The transmitter uses the second delay time setting method. With the configuration and characteristics as described above, the spread spectrum communication system according to the twenty-fourth embodiment has the same effects as those of the second and sixteenth embodiments.

(Twenty-fifth Embodiment) A spread spectrum communication system according to a twenty-fifth embodiment uses the transmitter shown in FIG. The receiver according to the twenty-fifth embodiment is the receiver of FIG. 14 used in the nineteenth embodiment, in which two latch units and a latch controller are provided as those corresponding to the delay elements 97 to 104. Is.

FIG. 23 is a schematic block diagram showing a receiver of a spread spectrum communication system according to the 25th embodiment of the present invention. The same parts as those of the receiver of FIG. 14 used in the nineteenth embodiment are designated by the same reference numerals, and the description thereof will be omitted as appropriate. The characteristic part will be mainly described.

Referring to FIG. 23, the receiver of the spread spectrum communication system according to the twenty-fifth embodiment has a receiving antenna 91, frequency converters 93 and 141, a local signal generator 129, a correlator 151, a distributor 95, and Latch units 331, 333, latch controller 335, differential unit 1
25 and a discriminator 127.

The distributor 95 divides the correlation signal (correlation output) a from the correlator 151 into two and generates a distribution signal. One distribution signal from the distributor 95 is the latch unit 3
31 and the other distribution signal is input to the latch unit 333.

The latch section 331 latches one distribution signal from the distributor 95 by the latch control signal b from the latch controller 335. The latch unit 333 receives the other distribution signal from the distributor 95 as the latch controller 33.
It is latched by the latch control signal c from 5.

That is, since the correlation signal a from the correlator 151 is in the form of time-multiplexed signals of four correlations, the multiplexed signals are generated by the latch control signals b and c from the latch controller 335. By latching with the latch units 331 and 333 at the timing of the delay time of 1, the signal before being delayed can be held. And
Based on the latch signals d and e from the latch units 331 and 333, the differential unit 125 performs differential decoding according to this.
Demodulate. The differentially decoded signal is output as data via the determination unit 127. This will be described in more detail.

FIG. 24 shows the latch portions 331 and 33 of FIG.
FIG. 3 is a diagram for explaining the 3 and the latch controller 335.

FIG. 24 (a) shows the correlation signal a of FIG. FIG. 24B shows the latch control signal b from the latch controller 335. FIG. 24C shows the latch control signal c from the latch controller 335 of FIG. FIG. 24D shows the latch signal d from the latch unit 331 of FIG. 24E shows the latch signal e from the latch unit 333 of FIG.

Referring to FIGS. 23 and 24, correlation signal a includes four multiplexed signals a1 to a4.
Due to the delay in the transmitter of FIG. 4, the signals a1 and a
It is separated from 2 by time τa. Signal a2 and signal a3
And are separated by time τb. The signal a3 and the signal a4 are separated by the time τc. That is, at the transmitter, the correlation peaks a1 to a4 are delayed by the time τ due to the delay.
The shapes are overlapped with a, τb, and τc.

Therefore, the latch timing of the latch units 331 and 333 is set between the latch unit 331 and the latch unit 333.
By alternately performing τa, τb, and τc, it becomes possible to make a difference from one delay before. explain in detail.

Latch controller 335 generates latch control signal b at the timing of signal a1 and signal a3 (FIG. 24 (b)). Then, the latch unit 331 latches the data of the signal a1 and the signal a3 by such a latch control signal b (FIG. 24 (d)).

The latch controller 335 generates the latch control signal c at the timing of the signals a2 and a4 (FIG. 24 (c)). The latch unit 333 latches the data of the signals a2 and a4 by such a latch control signal c (FIG. 24 (e)).

Therefore, the differential section 125 takes the differential between the data of the signal a1 and the data of the signal a2 at the point P1, and takes the differential between the data of the signal a2 and the data of the signal a3 at the point P2. , At the point P3, the data of the signal a3 and the data of the signal a4 are differentiated. In this way, the differential unit 125 performs differential decoding and demodulation.

In FIG. 24, only the receiver
Of the delay times, the shortest delay time is zero.
Has been adopted. Referring to FIG. 4, the delay of the delay element 29
Time τ ₂Is the same as the time τa in FIG.
Delay time τ of delay element 31_ThreeIs the same as time τa + time τb
The delay time τ of the delay element 33 of FIG._ThreeFigure 2
4 is the same as time τa + time τb + time τc.

The times τa, τb, and τc in FIG. 24 are the delay time τa of the delay element 97, the delay time τb of the delay element 99, and the delay element 10 of FIG. 14, respectively.
It is similar to the delay time τc of 1.

As described above, the delay elements 97 to 1 shown in FIG.
The latch units 331 and 333 and the latch controller 335 can be provided as those corresponding to No. 03 because the transmitter performs the delay and the like in the base band, so that the receiver can easily use the digital circuit. Because you can. The latch portion 331,
333 needs to be configured by a digital circuit.

As described above, in the twenty-fifth embodiment,
In the receiver, instead of providing a plurality of delay elements, the latch units 331 and 333 and the latch controller 335 are provided.
Is provided.

As a result, in the twenty-fifth embodiment, the circuit scale of the receiver can be made smaller than in the case where the differential decoding is performed by the differential section 125 using the signals from the plurality of delay elements. it can.

Furthermore, since the transmitter of FIG. 4 is used,
The same effect as the second embodiment is obtained.

Further, since the receiver of FIG. 14 and the receiver of the twenty-fifth embodiment are different only in the configuration, that is, whether there is a delay element or a latch section and a latch controller, the twenty-fifth embodiment. This embodiment also has the same effects as the nineteenth embodiment.

In the twenty-fifth embodiment, the transmission side delays the baseband signal to perform multiplexing. Furthermore, the receiver performs differential decoding (demodulation) by processing a baseband signal that is completely carrier-synchronized.

(Twenty-sixth Embodiment) In a spread spectrum communication system according to a twenty-sixth embodiment, its transmitter and receiver have the same configurations as those of the transmitter and receiver of the twenty-fifth embodiment. is there. That is, the twenty-sixth embodiment uses the transmitter of FIG. 4 and the receiver of FIG. The difference is that the transmitter adopts the second delay time setting method and sets the delay time in the same manner as in the sixth embodiment. That is, in the transmitter, the delay time is set so that the time difference between adjacent signals among the multiplexed signals becomes the same. Further, in FIG. 24, τa = τb = τc, which is different in that the time interval of the latch control signal is also constant.

Since it has the above-mentioned structure, the 26th
In this embodiment, the same effect as that of the twenty-fifth embodiment can be obtained.

(Twenty-seventh Embodiment) The spread spectrum communication system according to the twenty-seventh embodiment uses the transmitter shown in FIG. In addition, in the 27th embodiment, the second
In the receiver of FIG. 21 of the third embodiment, a latch unit and a latch controller are provided instead of the plurality of delay elements.

FIG. 25 is a schematic block diagram showing a receiver of a spread spectrum communication system according to the 27th embodiment of the present invention. The same parts as those in FIGS. 21 and 23 are designated by the same reference numerals, and the description thereof will be omitted as appropriate. The characteristic part will be mainly described.

Referring to FIG. 25, the receiver of the spread spectrum communication system according to the twenty-seventh embodiment has a receiving antenna 91, a frequency converter 93, a distributor 95, frequency converters 241, 243, correlators 311 and 313. , Distributors 245, 247, a local signal generator 129, latch units 341, 343, 345, 347, a latch controller 335, a differential unit 125, and a discrimination unit 127.

Referring to FIG. 25, correlation signal a1 which is the pseudo baseband from correlator 311 is distributed by distributor 24.
5, the latch portions 341 and 343 are divided into two.
Is input to Here, the latch units 341 and 343 have latch control signals b1 and c from the latch controller 335.
1 latches the signals input to the latch units 341 and 343.

In the latch sections 341 and 343,
The timing of latching, that is, the timing of the latch control signals b1 and c1 from the latch controller 335 is the same as that described in the twenty-fifth embodiment. FIG.
The correlation signal a1, the latch control signal b1, and the latch control signal c1 of 5 correspond to the correlation signal a, the latch control signal b, and the latch control signal c of FIG. 23, respectively.

The distributor 247 divides the correlation signal a2, which is the pseudo baseband from the correlator 313, into two and inputs them to the latch units 345 and 347.

Latch units 345 and 347 latch the signal from distributor 247 in response to latch control signal b2 and latch control signal c2 from latch controller 335. That is, the latch in the latch units 345 and 347 is the same as the above-described latch units 341 and 343. The correlation signal a2 and the latch control signal b2 in FIG.
23 and the latch control signal c2 are the correlation signals a,
This corresponds to the latch control signal b and the latch control signal c.

As described above, in the twenty-seventh embodiment, the latch section 3 is used instead of the plurality of delay elements in FIG.
41 to 347 and a latch controller 335 are provided.

As a result, in the twenty-seventh embodiment, the circuit scale of the receiver can be reduced as compared with the case where differential decoding is performed based on the signals from a plurality of delay elements.

Furthermore, in the 27th embodiment, since the transmitter of FIG. 4 is used, the same effect as that of the second embodiment can be obtained.

Further, the receiver of FIG. 21 and the receiver according to the present embodiment are different only in the configuration, that is, whether there is a delay element or a latch section and a latch controller. In this mode, the same effect as that of the 23rd embodiment is obtained.

In the twenty-seventh embodiment, the transmitter carries out multiplexing by delaying the baseband signal. Further, in the receiver, differential decoding (demodulation) is performed using a pseudo baseband signal that is not safely carrier-synchronized. The reason why the latch unit and the latch controller can be used instead of the plurality of delay elements is the same as in the 25th embodiment.

(Twenty-eighth Embodiment) A spread spectrum communication system according to a twenty-eighth embodiment uses a transmitter and a receiver having the same configuration as that of the twenty-seventh embodiment. That is, the transmitter of FIG. 4 and the receiver of FIG. 25 are used.

The difference from the twenty-seventh embodiment is that the second delay time setting method is adopted and the delay time of the transmitter is set as in the sixth embodiment. That is, the delay time in the transmitter is set so that the time differences between the adjacent signals multiplexed are all the same. Further, they are different in that the generation timings of the latch control signals from the latch controller 335 are the same.

With the above structure, the twenty-eighth embodiment has the same effect as the twenty-seventh embodiment.

(Twenty-ninth Embodiment) In the above-described first to twenty-eighth embodiments, DBPSK or the like is used as a reference, but a correlator (correlator) is used for an I channel and a Q.
By preparing the channels, it is possible to realize a spread spectrum communication system with the same effects as those of the above-described embodiments even with a phase modulation system such as DQPSK or an amplitude phase modulation system, and generality is not lost.

A spread spectrum communication system according to the twenty-ninth embodiment shows an example in which the DQPSK system is adopted.

FIG. 26 is a schematic block diagram showing a transmitter of a spread spectrum communication system according to a twenty ninth embodiment of the present invention. The same parts as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted as appropriate. The characteristic part will be mainly described. FIG. 26 corresponds to the transmitter of FIG. 1 of the spread spectrum communication system using the DBPSK system.

Referring to FIG. 26, the transmitter of the spread spectrum communication system according to the 29th embodiment of the present invention is
Data generator 1, differential encoder 3, S / P converter 5, multipliers 351, 353, 355, 357, 359, 36
1, 363, 365, PN generator 7, modulators 367, 3
69, 371, 373, local signal generator 9, delay elements 27, 29, 31, 33, multiplexer 35, frequency converter 37, power amplifier 39 and transmission antenna 41.

The difference from the DBPSK system (the difference from FIG. 1) is that the signal from the differential encoder 3 is divided by the S / P converter 5 so that the number of parallel signals is doubled. (The number of parallels is 8 in the present embodiment, and 4 in FIG. 1). Then, the multipliers 351 to 36
5 outputs eight parallel signals P1 to P8 to the PN generator 7
Multiply with the spreading code from. The modulator 367 is a multiplier 3
2-bit data from 51 and 353 is used for DQPSK modulation. The same applies to the modulators 369 to 373. Although the above is the difference from FIG. 1 that employs the DBPSK system, the processing in the subsequent stage from the modulators 367 to 373 is the same as that of the transmitter of FIG. Therefore, the first or second delay time setting method is adopted.

FIG. 27 is a schematic block diagram showing a receiver of a spread spectrum communication system according to the 29th embodiment of the present invention. The same parts as those in FIG. 8 are designated by the same reference numerals, and the description thereof will be omitted as appropriate. The characteristic part will be mainly described.

The receiver of FIG. 27 corresponds to the receiver of FIG. 8 of the spread spectrum communication system using the DBPSK system. Referring to FIG. 27, the receiver of the spread spectrum communication system according to the twenty-ninth exemplary embodiment of the present invention includes a receiving antenna 91, a frequency conversion unit 93, and a distributor 9.
5, delay elements 381, 383, 385, 387, frequency converters 389, 391, 393, 395, 397, local signal generator 129, correlators 399, 401, 4
03,405,407,409,411,413,41
5, 417, a differential amplifier 125, and a discriminator 127. The differential unit 125 is similar to the differential unit 125 of FIG.

The difference from the DBPSK system is that the local signal generator 129 is used in the frequency converters 389 to 397.
After being frequency-converted using the cos component and sin component from, the I signal (in-phase signal) and the Q signal (quadrature signal) are input to the correlators 399 to 417. The processes after the correlators 399 to 417 are the same as those in FIG.

As described above, in the twenty-ninth embodiment,
The fifth embodiment (the transmitter is FIG. 1, the receiver is FIG. 8) is D
While the BPSK system is used, the DQPSK system is used.

Therefore, in the 29th embodiment, the fifth
The same effect as that of the embodiment is obtained.

In the twenty-ninth embodiment, the transmitter and receiver corresponding to the transmitter of FIG. 1 and the receiver of FIG. 8 are shown, but other than this, in order to correspond to the DQPSK system, By doubling the parallel number of the transmitter adopting the DBPSK system and using it as I (in-phase) and Q (quadrature) data, all the above-described embodiments can be supported. This is because the difference between the DBPSK method and the DQPSK method is whether the phase is represented by 1 bit or 2 bits.

(Thirtieth Embodiment) In the first to twenty-ninth embodiments, when the time difference between the delay times is one chip or more in the receiver (first embodiment)
2) and the case where the time difference between the delay times is the same for one chip or more (second delay time setting method).

However, when constructing an actual circuit, when the delay element is configured in the intermediate frequency band (IF band), it is difficult to set the time difference between the delay times to an arbitrary time, and it is attempted to make them all the same. However, depending on the number of multiplexes, it may not be possible.

Further, when the delay element is formed of a base band or a pseudo base band, a digital delay element or the like is used, but there is a problem that the spreading code is not divisible by the desired parallel number (multiplex number). For example, when the spreading factor is 16 chips and it is divisible by 4 in the case of 4-multiplexing, there are times when it becomes unsuitable because 15 fractions give a fraction. Even with 16 chips, if it is multiplexed into 5, it cannot be divided.

Therefore, in the spread spectrum communication system according to the thirtieth embodiment, if there is a problem that the delay times at the transmitters are the same only when the delay times are the same and there is a problem such that some of them are the same. , And the rest of the time is arbitrary. The reverse is also possible.

As a result, in the thirtieth embodiment, the degree of freedom in designing can be increased when configuring a circuit of a spread spectrum communication system with feasibility. Furthermore, in the thirtieth embodiment, the multiplexing number can be determined regardless of the number of chips of the spread code, and the circuit of the spread spectrum communication system can be freely assembled.

The thirtieth embodiment uses any of the transmitters and receivers shown in the first to twenty-ninth embodiments. Also, depending on the number of multiplexes in the transmitter (depending on the number of multiplexes when the time difference between delay times is the same for one chip or more and the number of multiplexes for one time or more for an arbitrary time), The receiver in the twenty-ninth embodiment is used in combination. Therefore, the effects corresponding to the first to twenty-ninth embodiments are obtained.

(Thirty-first Embodiment) In the spread spectrum communication system according to the thirty-first embodiment, the differential unit 125 and the discriminating unit 12 of the receivers of the fifth to thirtieth embodiments.
Between 7 and P, which can absorb the influence of multipath etc.
A DI (post detection integrator) unit is provided. An example will be described.

FIG. 28 is a schematic block diagram showing a receiver of the spread spectrum communication system according to the 31st embodiment of the present invention. The same parts as those in FIG. 8 are designated by the same reference numerals, and the description thereof will be omitted as appropriate. The receiver of FIG. 28 is provided with a PDI unit 421 between the discrimination unit 127 and the differential unit 125 of the receiver of FIG. Here, the transmitter uses the transmitter of FIG.

Referring to FIG. 28, the receiver of the spread spectrum communication system according to the 31st embodiment of the present invention is
Receiving antenna 91, frequency converter 93, distributor 95, delay elements 97 to 103, frequency converters 105 to 113, local signal generator 129, correlators 115 to 123,
The differential unit 125, the PDI unit 421, and the determination unit 127 are included.

Referring to FIG. 28, PDI is the PDI unit 4
In 21, it spreads the differential decoded signal F by multipath, carried out by integrating for a predetermined time (0 to T _M). Regarding PDI, by Mitsuo Yokoyama
It is described in detail in "Spread spectrum communication system" (Science and Technology Publishing Company).

FIG. 29 is a diagram for explaining a general PDI and a PDI according to the present embodiment.

FIG. 29A is a diagram for explaining a general PDI, and FIG. 29B is a diagram for explaining a PDI according to the present embodiment.

Referring to FIG. 29, as shown in (a),
In general, the PDI has an advantage that it can demodulate not only one wave but also a multipath wave signal by taking a differential with respect to one period T of the spread code.

However, in a multipath environment in which high-speed fading occurs, the signal a2 and the signal a1 one cycle T before the spreading code change the environment at the time of pass, and the performance cannot be improved even if PDI is performed. Or, there were cases where the performance deteriorated.

In the thirty-first embodiment, as shown in (b), four signals are multiplexed during one period T of the spreading code, so that signal a1 and signal a2 and signal a2 and signal a are obtained.
3, the signal a3 and the signal a4, and the signal a4 and the signal b1 are differentiated. Therefore, the time required for the differential is a fraction of that in the case where multiplexing is not performed. As a result, the change at the time of passing is a fraction of that in the case of not multiplexing (FIG. 29A).
Therefore, even in a high-speed fading environment, PDI exerts its effect and good performance can be obtained.

As described above, in the thirty-first embodiment, the characteristics under the fading environment can be greatly improved as compared with the case where the multiplexing is not performed.

FIG. 30 is a diagram for explaining PDI in PDI section 421 in FIG.

FIG. 30A shows four multiplexed signals a.
1 to a4 are shown. Here, the differential unit 125 of FIG.
Signal a1 and signal a2, signal a2 and signal a3, signal a
3 and the signal a4 are differentiated.

FIG. 30B shows the signal a1 of FIG. 30A.
And the signal a2 are differential signals. Figure
The PDI unit 421 of 28 has a difference as shown in FIG.
PDI is performed using the signal after the movement. Sand
Then, the section T shown in FIG. _MDifferentially decoded between
PDI is performed by integrating the received signal.

FIG. 31 is a diagram for explaining another example of PDI in PDI section 421 of FIG. 28.

FIG. 31A shows four multiplexed signals a.
1 to a4 are shown. What is different from FIG. 30 is that there is an inverted portion in one signal.
The differential section 125 in FIG. 28 takes a differential between the signal a1 and the signal a2, the signal signal a2 and the signal a3, and the signal a3 and the signal a4.

FIG. 31 (b) shows the signal a1 of FIG. 31 (a).
And the signal a2 after the differential is taken. The PDI unit 421 of FIG. 28 performs PDI by integrating the differentially decoded signal in the section T _M as shown in FIG.

The reason why PDI is performed after differential decoding is that inconvenience occurs when there is an inverted portion in one signal as shown in FIG.
That is, if the positive and negative are reversed when the length is just the phase inversion due to fading, PD
If differential decoding is performed after performing I, inconvenience occurs. Therefore, PDI is performed after the differential decoding is performed.

As described above, in the 31st embodiment,
Since the differential decoding is performed using multiplexed signals with a short time interval between signals, the change at pass is small and high speed compared to the case where differential decoding is performed using non-multiplexed signals. Even under the fading environment of PDI, PDI can exert its effect and obtain good performance. Furthermore, since the same transmitter and receiver as the transmitter and receiver of the fifth embodiment are used, the same effect as that of the fifth embodiment is obtained.

In the thirty-first embodiment, the case where the PDI unit 421 is provided between the differential unit 125 and the discriminating unit 127 in FIG. 8 of the fifth embodiment has been described.
Even if the PDI is provided between the differential unit 125 and the discriminating unit 127 of the receiver according to the thirtieth embodiment, the same effect as described above can be obtained. Further, also in that case, the respective effects of the sixth to thirtieth embodiments can be obtained.

(Thirty-Second Embodiment) In the thirty-first embodiment, the signal one delay before is taken as a differential signal (adjacent signals of the multiplexed signals are differentiated from each other), and then PD
I was performed to show the merit of being able to follow high-speed fluctuations. In the spread spectrum communication system according to the thirty-second embodiment, the PDI is used by using the signal one delay before (using the signal preceding one of the two signals to be differentially decoded). , Controls the integration interval (window) and weights the integration.

For example, referring to FIG. 30, when the signals a2 and a3 are differentiated, the signals a2, a
3 is used as a pilot signal, which is a signal a1 (a signal one delay before the signal a2) before PDI window (FIG. 30).
Control of the section T _M ) and weighting of integration are performed.

As described above, in the thirty-second embodiment, a signal close in time (one delay before) is used as a pilot signal,
By controlling the PDI, it becomes possible to control the PDI with high accuracy. As a result, the 32nd embodiment can further improve the PDI effect as compared with the 31st embodiment. Further, the same effects as those of the fifth to thirty-first embodiments are obtained.

The transmitter and receiver of the thirty-second embodiment are similar to the thirty-first embodiment in that the fifth to third transmitters are the same.
The transmitter and the receiver according to the 0th embodiment are used, and in the receiver, a PDI unit that performs PDI is provided between the differential unit and the determination unit.

(Thirty-Third Embodiment) A transmitter and a receiver of a spread spectrum communication system according to a thirty-third embodiment are similar to the transmitter and the receiver according to the thirty-first embodiment, from the fifth to the fifth embodiment. The transmitter and the receiver according to the thirty embodiments are used, and in the receiver, P is provided between the differential section and the discrimination section.
A PDI unit for performing DI is provided.

In the 32nd embodiment, for example, FIG.
As shown in 0, when the signal a2 and the signal a3 are differentiated, the signal a1 that is one signal before the signal a2 is used as the pilot signal. However, in the thirty-third embodiment,
When the signal a2 and the signal a3 are differentiated, the signal a2
Signal from a few previous periods (not all shown)
Is used to control the PDI window T _M (time width for integrating the signal) and the weighting of the integration.

In terms of time, the multipath one delay before the demodulated wave is the closest to the multipath demodulated waveform, so that the signal one delay before is used as the pilot signal as in the thirty-second embodiment. However, although ideal, the signal one delay before may be corrupted by noise other than multipath.

For example, referring to FIG. 30, the signal obtained by taking the differential between the signal a2 and the signal a3 is shown in FIG.
When the signal shown in FIG. 30 is obtained, the signal that is closest to the signal multipath shown in FIG. 30B is the signal a1 multipath. However, due to noise other than multipath, the signal a
1 may be broken. Here, the “signal one delay before” refers to the signal a1, but generally speaking,
It is a signal that is one ahead of the previous signal (the signal that arrives earlier) of the two differential signals.

Therefore, in the thirty-second embodiment, the previous signal (the signal that arrives first) of the two signals that are the basis of the differentially decoded signal (the signal for which PDI is going to be performed). The average of a plurality of signals in front of is taken, and the PDI window and the weighting of the integral are controlled based on the average.

As a result, in the thirty-third embodiment, even if the signal one delay before is corrupted due to the influence of noise other than multipath, the influence can be reduced, and accurate PDI can be realized. Therefore, the error rate when demodulating can be improved.

Further, in the thirty-third embodiment, a plurality of signals are multiplexed by delaying the signals during one cycle of the spread code. Therefore, even if the average of a plurality of multiplexed and continuous signals is taken, the interval of the plurality of continuous signals is shorter in time than one spread code period. Therefore, even if the average of a plurality of continuous signals is taken, there is an advantage that the error is small for multipath.

Further, it becomes the source of the differentially decoded signal among a plurality of signals before the preceding signal (the signal arriving earlier) of the two signals which are the sources of the differential decoding. The closer the signal multipath is to the signal, the closer the signal multipath is to the differentially decoded signal.

Therefore, when averaging a plurality of multiplexed and continuous signals, the closer the signal is to the original signal of the differentially decoded signal for which PDI is to be performed, the greater the weighting becomes. By weighted averaging, it is possible to reduce the effects of noise and multipath other than multipath. Further, the same effects as those of the fifth to thirty-first embodiments are obtained.

That is, as the multipath, the delay before 1 delay is the closest, so when averaging, 1 delay, 2 delays, 3
The delay and the weighting are increased in the shorter time and the weighted average is performed.

In summary, this embodiment is characterized in that PDI is performed by using a plurality of two or more temporally fast signals as pilot signals and using their average or weighted average.

(Thirty-fourth Embodiment) FIG.
2 is a schematic block diagram showing a transceiver of the spread spectrum communication system according to the exemplary embodiment of FIG.

Referring to FIG. 32, the transmitter / receiver 4 of the spread spectrum communication system according to the 34th embodiment of the present invention.
37 includes a data generation unit 431, a transmission / reception unit 433, and a multiplex number / delay amount controller 435. The transmitter / receiver 433 uses any of the transmitters and receivers of the first to thirty-third embodiments.

In the first to thirty-third embodiments,
The number of multiplexed signals (the number of parallel signals) and the delay amount were fixed. However, as the number of multiplexes increases, the same C / N
There is a situation in which the error rate in (signal to noise ratio) becomes poor and communication becomes difficult.

Therefore, in the present embodiment, the number of multiplexing and the delay amount are changed from the outside according to the environment (error rate, C / N, delay profile, etc.) in which the transceiver used in the spread spectrum communication system is used. It was made possible. With reference to FIG. 32, the data generator 43
1 inputs data to a transmission unit (not shown) of the transmission / reception unit 433. Then, the data is multiplexed by delaying and output as a transmission signal a.

On the other hand, the receiver (not shown) included in the transmitter / receiver 433 receives the transmission signal b from another transmitter. Then, the signal is demodulated and output as demodulated data.

Then, the multiplexing number / delay amount controller 435 is externally controlled according to the use environment of the transceiver 437 to set the multiplexing number and delay amount of the transmitting / receiving unit 433.

In general, when installing or operating a wireless system, the size of the antenna and the amplifier power of the output are determined by setting the transmission rate and the distance at which communication is possible in advance according to the usage environment. Similarly to this, in the present embodiment, the transmitter / receiver 4 is determined from the required transmission rate and the desired error rate.
When 37 is installed, the number of multiplexed signals and the delay amount are determined and input from outside the transceiver 437. Then, according to the input, the multiplexing number / delay amount controller 435 causes the transmitting / receiving unit 4 to
The multiplexing number and delay amount of 33 will be set.

Since the error rate required depends on the content of data, for example, voice or data (10 ^{-3 for} voice, 10 ^{-8 for} data, etc.) The / delay amount controller 435 also receives a setting signal for setting the number of multiplexes and the amount of delay, and can change the number of multiplexes and the amount of delay according to the type of data.

Also, by an input from the outside, it is possible to increase the delay amount when the delay dispersion at the place of use is large, or to reduce the number of multiplexing when the distance between the transmitter and the receiver is large and the signal level is small.

As described above, in the 34th embodiment,
The number of multiplexes and the delay amount can be set according to the usage environment by inputting from the outside (external signal), and the line efficiency can be improved. The line efficiency is, for example, the data rate of transmission.

Furthermore, since the transmitter / receiver 433 uses any of the transmitters and receivers of the first to thirty-third embodiments, it is possible to use the transmitter and receiver of the first to thirty-third embodiments. It also has the same effect.

(Thirty-Fifth Embodiment) A transmitter / receiver of a spread spectrum communication system according to a thirty-fifth embodiment is a transmitter / receiver 437 shown in FIG. 32 for calculating an error rate from demodulated data (error rate calculating circuit). Is provided. Then, based on the error rate from this error rate calculation circuit,
The number of multiplexes and the delay amount are set.

FIG. 33 is a schematic block diagram showing a transmitter / receiver of a spread spectrum communication system according to the 35th embodiment of the present invention. The same parts as those in FIG. 32 are designated by the same reference numerals, and the description thereof will be omitted as appropriate. The characteristic part will be mainly described.

The transmission / reception section 433 includes an error rate calculation circuit (not shown). Then, based on the error rate from the error rate calculation circuit, the multiplex number / delay amount controller 435
Sets the multiplex number and delay amount of the transmission / reception unit 433.
Here, the multiplex number and the delay amount are set so that the actual error rate is lower than the desired error rate.

FIG. 34 is a diagram showing the transceiver 437 of FIG. 33 in more detail. The same parts as those in FIG. 33 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

Referring to FIG. 34, the transceiver 437 includes a data generator 431, a multiplex number / delay amount controller 43.
5, a transmitter 443 and a receiver 445 are included. The multiplexing number / delay amount controller 435 includes a controller 439 and a processing unit 441.

The processing section 441 receives the information on the error rate from the error rate calculating circuit (not shown) of the receiving section 445,
The number of multiplexing and the amount of delay in the transmitting unit 443 are determined.
Then, the controller 439 sets the multiplex number and the delay amount of the transmission unit 443 so that the multiplex number and the delay amount of the transmission unit 443 become the multiplex number and the delay amount determined by the processing unit 441.

The data generator 431 receives the number of multiplexed signals set by the controller 439 and generates data according to the transmission capacity determined by the number of multiplexed signals.

[0433] In this way, the delay amount and the multiplexing number of the transmitting unit 443 are set. Then, the data from the data generator 431 is processed based on the number of multiplexing and the delay amount, and is output as the transmission signal a. The receiving unit 445 receives the transmission signal b from another transmitter, demodulates it, and outputs it as demodulated data.

Here, the relationship between the number of multiplexes and the delay amount and the error rate will be described. For example, C / N = 12 dB
, The BER (error rate) = 10 when the number of multiplexing is 5.
^{-It is} about ² . Therefore, if the number of multiplexes is set to 5 → 4 → 3 → 2 → 1 in order to improve the error rate, the BER is 1 × 10.
^-2 → 4 × 10 ^-3 → 1.5 × 10 ^-3 → 7 × 10 ^-5 → 1 ×
It will be improved to 10 ^-8 .

Therefore, when the error rate is poor, this can be improved by reducing the number of multiplexes. On the other hand, when the actual error rate is about 10 ⁻⁵ and is good, the transmission amount can be increased by increasing the number of multiplexing.

As described above, in this embodiment, the number of multiplexes and the delay amount are set in real time in accordance with the current status of the line (error rate). As a result, in the thirty-fifth embodiment, the optimum multiplexing number and delay amount are always obtained, and the line efficiency can be improved.

In the thirty-fourth embodiment, the number of multiplexes and the delay amount are set in advance according to the usage environment, but the usage environment (communication environment) is constantly changing and the optimum value is set. Hard to get.

The transmitter / receiver of the thirty-fifth embodiment,
Since the transceiver of the thirty-fourth embodiment is further provided with an error rate calculation circuit, the thirty-fifth embodiment has the same effect as the thirty-fourth embodiment.

Further, in the communication system in which the data to be transmitted includes the error correction code, the number of multiplexing and the delay amount of the transmitting section 443 can be determined by the error rate detected by the receiving section 445. Also in this case, the same effect as described above can be obtained.

The details of the transceiver shown in FIG. 32 are also shown in FIG.
Is the same as In this case, there is no error rate calculation circuit.

(Thirty-sixth Embodiment) A transmitter / receiver of a spread spectrum communication system according to a thirty-sixth embodiment
Instead of the error rate calculation circuit of the transceiver of FIGS. 33 and 34, a means (C / N calculation circuit) for obtaining a signal noise ratio (C / N) from a received signal, and a multiplex number suitable for C / N and A table in which the delay amount is set is provided.
33 and 34 will be described below as a transceiver of the spread spectrum communication system according to the present embodiment.

Referring to FIG. 33, the transmitting / receiving section 433 is
A / N calculating circuit is provided, and the C / N calculating circuit obtains C / N based on a transmission signal b from another transmitter. Then, the multiplex number / delay amount controller 435 determines the multiplex number and the delay amount based on the C / N from the C / N calculation circuit, and sets the multiplex number and the delay amount of the transmitting / receiving unit 433.

The multiplex / delay amount controller 435
Has a table in which the number of multiplexes and the amount of delay suitable for C / N are set as described above.
Based on N, the number of multiplexing and the delay amount are determined. FIG. 34
The processing unit 441 has such a function.

As described above, in the thirty-fifth embodiment, the number of multiplexes and the delay amount are determined according to the error rate.
In the present embodiment, the number of multiplexes and the delay amount are determined by C / N.

When the C / N is measured, the error rate at that time can be calculated from the C / N by holding the characteristic in advance, so that the multiplexing can be performed according to the actual error rate. The number and amount of delay can be controlled. explain in detail.

FIG. 35 is a diagram showing the relationship between the error rate (BER) and the signal-to-noise ratio (C / N).

Arrows A1, A2, A3, A4 and A5
However, the respective lines correspond to the cases where the numbers of multiplexing are 1, 2, 3, 4, and 5. The vertical axis shows the error rate (BER)
And the horizontal axis represents the signal-to-noise ratio (C / N).

Referring to FIG. 35, when the C / N is constant, the error rate becomes worse as the number of multiplexing increases. Further, when the error rate is fixed, the C / N becomes larger as the number of multiplexing increases.

When the C / N is measured, the error rate at that time can be calculated from the C / N by holding the characteristic as shown in FIG. 35 in advance, so that the multiplexing is performed according to the actual error rate. You can control the number and the amount of delay.

As described above, in the 36th embodiment,
Since it has a C / N calculation circuit that calculates C / N according to the received signal (transmission signal b) and a table that sets the number of multiplexes and the delay amount suitable for C / N, the current line status The number of multiplexes and the delay amount are controlled in real time according to (C / N). As a result, in the thirty-sixth embodiment, the optimum multiplexing number and delay amount are always set according to the usage environment, and the line efficiency and throughput can be improved.

Further, in the thirty-sixth embodiment, since the transmitter and receiver according to any one of the first to thirty-third embodiments are used as the transceiver, the ones of the first to thirty-third embodiments are different. It also produces either effect.

(Thirty-Seventh Embodiment) A transmitter / receiver of a spread spectrum communication system according to a thirty-seventh embodiment is different from the transmitter / receiver in FIGS. 33 and 34 in that the received signal is used instead of the error rate calculation circuit. A means (delay amount calculation circuit) for obtaining the delay amount of the delayed wave is provided. Hereinafter, the transceivers of FIGS. 33 and 34 will be described as the transceiver according to the present embodiment.

Referring to FIG. 33, transmitting / receiving section 433 has a delay amount calculating circuit for receiving transmission signal b and obtaining the delay amount (delay profile) of the delayed wave due to multipath or the like.

Then, based on the delay amount (delay profile) from the delay amount calculation circuit, the multiplex number / delay amount controller 435 determines the multiplex number and delay amount, and the transmitting / receiving unit 4
The number of multiplexing of 33 and the delay amount are set. Note that the processing unit 441 in FIG. 34 receives the delay amount (delay profile) from the delay amount calculation circuit included in the receiving unit 445, and determines the multiplexing number and the delay amount of the transmitting unit 443. A method for determining the multiplexing number and the delay amount of the transmission unit 443 based on the delay amount obtained from the transmission signal b will be described in detail.

FIG. 36 is a diagram for explaining a method of obtaining the number of multiplexes and the delay amount based on the delay amount (delay profile) of the received signal.

FIG. 36 (a) shows a correlation signal (correlation peak) when there is no multipath in the transmission path. Fig. 36
(B) and (c) have shown the correlation signal when there is a multipath in a transmission line. 36 (a) to (c),
A signal based on the transmission signal b from the other transmitter in FIG.
Correlator (not shown) in the receiver 445
Is a correlation signal obtained by correlation with the spreading code used on the transmission side.

As shown in FIGS. 35 (b) and 35 (c), when there are multipaths, the correlation signal becomes a signal having a delay profile due to many delayed waves due to the multipaths. With reference to FIG. 36C, consider the following multiplexed signal with respect to signal A. When the signal multiplexed after the signal A is the signal B, the signal A and the signal B overlap with each other, which causes an error rate deterioration during demodulation.

On the other hand, when the signal next to the signal A is the signal D, the signals do not overlap with each other and the error rate is not deteriorated, but the signal A and the signal D are greatly separated from each other, so that the number of multiplexing is reduced. Will end up. Therefore, when the signal following signal A is signal C, the signals do not overlap with each other and the error rate does not deteriorate. Further, unlike the signal d, it is not far from the signal a, so that the number of multiplexed signals can be increased and the transmission amount can be increased.

As described above, the multiplex number / delay amount controller 135 determines the multiplex number and delay amount based on the information (delay amount) regarding the delay profile from the transmitting / receiving unit 443, and the multiplex number and delay amount of the transmitting / receiving unit 433. To set.

As described above, in the 37th embodiment,
Since the number of multiplexes and the delay amount are determined by the delay profile (delay amount) of the transmission path, the transmission amount can be optimized without error rate deterioration.

Furthermore, in the thirty-seventh embodiment, since the transmitter and receiver according to any of the first to thirty-third embodiments are used, any one of the first to thirty-third embodiments is used. It also has an effect.

(38th Embodiment) In the 38th embodiment, the transmitter / receiver of the spread spectrum communication system according to any of the 34th to 37th embodiments is used.

Here, in the present embodiment, the number of multiplexes and the delay amount determined according to the usage environment (error rate, C / N, delay profile, etc.) are embedded in a part of the transmission data, and The number of multiplexes and delay amount used for packet frames are transmitted. Then, the transceiver on the receiving side automatically sets its own multiplex number and delay amount using the sent information on the multiplex number and delay amount.

That is, by sending the information regarding the multiplex number and the delay amount for the next packet as a flag on the data format, the system can be matched with the other station without discrepancies in the multiplex number and the delay amount. Therefore, the multiplexing number and the delay amount can be changed for each packet, and the multiplexing number and the delay amount can be optimized.

As described above, in the thirty-eighth embodiment, the transmission side sends the data of the multiplex number and the delay amount set according to the use environment to the data generating section 431, and the data of the multiplex number and the delay amount is sent. Is added to the transmission data and transmitted, and the receiving side demodulates the number of multiplexed signals (the number of distributed signals) based on the transmitted data of the number of multiplexed signals and the amount of delay.
And set the delay amount.

From the above, in the thirty-eighth embodiment, the multiplexing number and the delay amount can be optimized for each data packet, and the multiplexing number and the delay amount can be optimized according to the time change of the usage environment. Is possible.

Furthermore, in the thirty-eighth embodiment, any one of the transceivers in the thirty-fourth to thirty-seventh embodiments is used as a transceiver, so that one of the thirty-fourth to thirty-seventh embodiments. It also has an effect.

(Thirty-Ninth Embodiment) In the spread spectrum communication system according to the thirty-ninth embodiment, the transceiver according to the thirty-eighth embodiment is used as one transceiver, and the other transceiver from the fifth transceiver is used. The transmitter and the receiver according to any one of the 33rd embodiment are used.

In the thirty-eighth embodiment, the transmitting side includes the information of the multiplex number and the delay amount set according to the usage environment in the transmission signal, so that the receiving side can obtain the multiplex number and the delay amount of the demodulation system. Although set, in the present embodiment,
Similar to the thirty-eighth embodiment, information on the number of multiplexes and the delay amount determined on the transmitting side according to the use environment is sent as a transmission signal (the number of multiplexes and delay amounts of the transmitter-receiver is the operating environment. On the receiving side, based on the transmitted information on the multiplexing number and the delay amount of the transmitting side, the multiplexing number and the delay amount of the demodulation system (receiver) and the modulation system (transmitter). To set.

As described above, in the 39th embodiment,
Since it is only necessary to control the number of multiplexes and the amount of delay for one of the transmitters and receivers facing each other, using the information about the number of multiplexes and the amount of delay determined by one of the transmitters and receivers, the number of multiplexes and the delay of the other transmitter and receiver are used. You can control the amount.

As a result, in the thirty-ninth embodiment, a circuit for judging the use environment (this is the error rate calculation circuit of the thirty-fifth embodiment, the C / N calculation circuit of the thirty-sixth embodiment,
Since the delay profile calculation circuit (delay amount calculation circuit) and the like of the 37th embodiment) and the multiplex number / delay amount control circuit can be used for only one of the opposing transceivers, the spread spectrum communication system can be made compact. And cost reduction can be achieved.

Further, since the transceiver used in the 38th embodiment is used, the same effect as that of the 38th embodiment can be obtained.

Further, one of the transmitter and the receiver is connected to the first to the third.
Since any one of the transmitter and the receiver of the third embodiment is used, the effect of any of the first to thirty third embodiments can be obtained.

(Fortieth Embodiment) First, the multi-rate system will be described. The multi-rate method is one of the data transmission methods used in recent multimedia and the like, and is a method in which the transmission rate is changed according to the contents of communication such as image data and audio data. Therefore, in the conventional communication system, a method of changing the communication symbol rate or changing the communication time length has been adopted in accordance with the multirate.

For example, 5 Mbps (bit per second)
If there is a difference in the transmission rate between 1 Mbps and 1 Mbps, the conventional BP
In the communication system using the SK modulation method, the symbol rate is also 5 Msps (symbol per second) and 1 Msps.
Therefore, the transmission bandwidth was changed five times. For this reason, it is necessary to change the frequency channel, and the channel width and the number of channels are controlled depending on the usage situation, which is difficult to control. The transmitter of the spread spectrum communication system according to the present embodiment is for solving such a problem.

FIG. 37 is a schematic block diagram showing a transmitter of a spread spectrum communication system according to the fortieth embodiment.

Referring to FIG. 37, the transmitter of the spread spectrum communication system according to the fortieth embodiment of the present invention
It includes a multi-rate data generator 451, a multiplexing number / delay amount determination circuit 453, and a transmitter 455.

The transmitting unit 455 uses the transmitter of the spread spectrum communication system according to the first to fourth and twenty-ninth embodiments.

The multi-rate data generation unit 451 determines the contents of the information to be transmitted (eg, voice, image, etc.).
Data is generated by changing the data rate. Then, the multiplexing number / delay amount determining circuit 453 determines the multiplexing number and the delay amount so that the symbol rate is kept constant regardless of the data rate, based on the information from the multi-rate data generating unit 451, and the transmitting unit 455. Set the multiplex number and delay amount of.

For example, if the data rate is 3 Mbps, the symbol rate is always 1 Msps by setting the number of multiplexing to 3 when the number of multiplexing is 3 and 5 Mbps.
You can communicate while maintaining the same bandwidth.

Also, with respect to the amount of delay, the amount of delay is increased when the number of multiplexing is 3, and the amount of delay is decreased when the number of multiplexing is 5, according to the number of multiplexing.

Here, the symbol rate indicates the rate after serial / parallel conversion (S / P conversion). In FIG. 1, FIG. 4, FIG. 5, FIG. 6 and FIG. 26, the rate after serial / parallel conversion by the S / P converter 5 is the symbol rate. In the case of ¼ conversion (for example, in FIG. 1, the S / P conversion unit 5 converts the serial signal from the differential encoding unit 3 into four parallel signals P1 to P4; If the bit rate is 4 Mbps, the symbol rate is 1 Msps
Becomes

As described above, in the 40th embodiment,
Since the number of multiplexes and the amount of delay are determined so that the symbol rate becomes constant, it is possible to communicate while maintaining the same bandwidth,
Multi-rate conversion can be easily realized without the need to control frequency channels.

That is, the circuits other than the circuit related to the multiplexing can be the same regardless of the data rate, and the multi-rate can be realized with a slight change (the number of multiplexing / delay amount determining circuit 453 is provided). become able to.

Furthermore, since the transmitter of the spread spectrum communication system according to the first to fourth embodiments is used in the fortieth embodiment, any of the transmitters according to the first to fourth embodiments is used. It also has the effect.

[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 diagram showing the relationship between data and spreading codes in the transmitter of the spread spectrum communication system according to the first embodiment of the present invention.

FIG. 3 is a diagram for explaining differential encoding in the differential encoding unit in FIG.

FIG. 4 is a schematic block diagram showing a transmitter of a spread spectrum communication system according to a second embodiment of the present invention.

FIG. 5 is a schematic block diagram showing a transmitter of a spread spectrum communication system according to a third embodiment of the present invention.

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

FIG. 7 is a diagram for explaining in detail the operation of the latch unit and the latch controller of FIG.

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

9 is a diagram for explaining differential decoding in the differential unit of FIG.

FIG. 10 is a schematic block diagram showing a receiver of a spread spectrum communication system according to a sixth embodiment of the present invention.

FIG. 11 is a diagram for explaining differential decoding in the differential unit in FIG.

FIG. 12 is a schematic block diagram showing a receiver of a spread spectrum communication system according to a seventh embodiment of the present invention.

FIG. 13 is a schematic block diagram showing a receiver of a spread spectrum communication system according to an eighth embodiment of the present invention.

FIG. 14 is a schematic block diagram showing a receiver of a spread spectrum communication system according to a ninth embodiment of the present invention.

FIG. 15 is a schematic block diagram showing a receiver of a spread spectrum communication system according to a tenth embodiment of the present invention.

FIG. 16 is a schematic block diagram showing a receiver of a spread spectrum communication system according to an eleventh embodiment of the present invention.

17 is a diagram for explaining differential decoding in the differential unit of FIG.

FIG. 18 is a schematic block diagram showing a receiver of a spread spectrum communication system according to a twelfth embodiment of the present invention.

FIG. 19 is a schematic block diagram showing a receiver of a spread spectrum communication system according to a thirteenth embodiment of the present invention.

FIG. 20 is a schematic block diagram showing a receiver of a spread spectrum communication system according to a fourteenth embodiment of the present invention.

FIG. 21 is a schematic block diagram showing a receiver of a spread spectrum communication system according to a fifteenth embodiment of the present invention.

FIG. 22 is a schematic block diagram showing a receiver of a spread spectrum communication system according to a sixteenth embodiment of the present invention.

FIG. 23 is a schematic block diagram showing a receiver of a spread spectrum communication system according to a twenty-fifth embodiment of the present invention.

FIG. 24 is a diagram for explaining operations of the latch unit and the latch controller in FIG. 23.

FIG. 25 is a schematic block diagram showing a receiver of a spread spectrum communication system according to a twenty seventh embodiment of the present invention.

FIG. 26 is a schematic block diagram showing a transmitter of a spread spectrum communication system according to a twenty ninth embodiment of the present invention.

FIG. 27 is a schematic block diagram showing a receiver of a spread spectrum communication system according to a twenty ninth embodiment of the present invention.

FIG. 28 is a schematic block diagram showing a receiver of a spread spectrum communication system according to a thirty-first embodiment of the present invention.

FIG. 29 is a diagram for explaining PDI in the PDI unit of FIG. 28.

FIG. 30 is a diagram showing a multiplexed signal and a signal subjected to PDI in the case where there is multipath in the thirty-first embodiment.

FIG. 31 is a diagram showing another multiplexed signal and a signal subjected to PDI in the case where there is multipath in the thirty-first embodiment.

FIG. 32 is a schematic block diagram showing a transceiver of a spread spectrum communication system according to a 34th embodiment of the present invention.

FIG. 33 is a schematic block diagram showing a transceiver of a spread spectrum communication system according to a thirty-fifth embodiment of the present invention.

FIG. 34 is a diagram showing the transceiver of FIG. 33 in more detail.

FIG. 35 is a diagram showing the relationship between error rate and C / N (signal noise ratio) in the thirty sixth embodiment of the present invention.

FIG. 36 is a diagram for explaining a procedure for determining the number of multiplexes and the delay amount by using the delay profile in the transmitter / receiver of the spread spectrum communication system according to the 37th embodiment of the present invention.

FIG. 37 is a schematic block diagram showing a transmitter of a spread spectrum communication system according to a fortieth embodiment of the present invention.

FIG. 38 is a schematic block diagram showing a transmitter of a conventional spread spectrum communication system.

FIG. 39 is a diagram for explaining a problem of a conventional spread spectrum communication system.

FIG. 40 is a diagram showing parallel-converted data and a first spreading code in FIG. 38.

FIG. 41 is a diagram for describing an adverse effect caused by the timing of the first spreading code and the timing of the parallel-converted data being deviated in the transmitter of FIG. 38.

[Fig. 42] Fig. 42 is a diagram illustrating a specific example of the correlation output when the timings of the data and the first spreading code match.

[Fig. 43] Fig. 43 is a diagram illustrating a specific example of the correlation output when the timings of the data and the first spreading code are deviated.

[Explanation of symbols]

1,431 Data generator 3 Differential encoder 5,461 S / P converter 7,475 PN generator 9,129 Local signal generator 11-17,351-365 Multiplier 19-25,51,367- 373 modulator 27-33, 97-103, 211, 249-263
299,301,381-387 Delay element 35 Combiner 37,93,105-113,133,135,14
1,171 to 189,217 to 223,241,24
3,291,293,389-397 Frequency converter 39 Power amplifier 41 Transmission antenna 61-75 Delay device 81-87,331,333,341-347 Latch unit 89,335 Latch controller 91 Reception antenna 95,161-169 , 213, 215, 245, 24
7 distributor 115-123,137,139,151,191-2
09,225-231,311,313,399-41
7 Correlator 125 Differential unit 127 Discrimination unit 421 PDI unit 433 Transmission / reception unit 435 Multiplex number / delay amount controller 437 Transceiver 439 Controller 441 Processing unit 443,455 Transmission unit 445 Reception unit 451 Multi-rate data generation unit 453 Multiplex number / delay Quantity determining circuit 463, 465, 467 Spreading modulator 469, 471, 473 Delay circuit 477 Synchronizing circuit 479 Adder 481 Amplifier 483 Local oscillator 485 Synchronizing PN generator 487 Multiplying circuit 489 Mixing circuit

Claims (8)

[Claims] 1. A transmitting means and a receiving means, wherein the transmitting means converts the data string into a plurality of parallel signals, a serial / parallel converting means, a spreading code generating means for generating a spreading code, and the plurality of Multiplying the parallel signal and the spreading code to generate a plurality of spreading signals, modulating means for modulating the plurality of spreading signals to generate a plurality of intermediate frequency signals, and a plurality of different delay times. And delaying the plurality of intermediate frequency signals with the plurality of different delay times,
A delay signal generating unit configured to generate a plurality of delay signals; and a transmission signal output unit configured to combine the plurality of delay signals and output as a transmission signal, wherein the plurality of different delay times are equal to or more than 1 chip. A spread spectrum communication system having an arbitrary time difference. 2. A transmitting means and a receiving means, wherein the transmitting means converts the data string into a plurality of parallel signals, a serial / parallel converting means, a spreading code generating means for generating a spreading code, and the plurality of Of the parallel signal and the spreading code to generate a plurality of spreading signals, and a plurality of different delay times, the plurality of spreading signals that are baseband, the plurality of different delay times Delaying means for generating a plurality of delay signals, and multiplexing the plurality of delay signals, including a transmission signal output means for outputting as a transmission signal, the plurality of different delay times are mutually, A spread spectrum communication system having an arbitrary time difference of 1 chip or more. 3. A transmission means and a reception means are provided, wherein the transmission means has a serial / parallel conversion means for converting a data string into a plurality of parallel signals, has a plurality of different delay times, and is a baseband. A first delay unit that delays the plurality of parallel signals by the plurality of different delay times to generate a plurality of delayed parallel signals; a spread code generation unit that generates a spread code; and a plurality of different delay times. Having the same plurality of delay times as above, delaying the spread code with the plurality of delay times,
Second delay means for generating a plurality of delay spread codes; multiplication means for multiplying the plurality of delayed parallel signals by the plurality of delay spread codes to generate a plurality of spread signals; A plurality of signals that are based on each other, and a transmission signal output unit that outputs as a transmission signal, wherein the multiplication unit multiplies the delay parallel signal and the delay spread code having the same delay time, A spread spectrum communication system in which different delay times have an arbitrary time difference of 1 chip or more from each other. 4. A transmission means and a reception means, wherein the transmission means converts the data sequence into a plurality of parallel signals, and a serial / parallel conversion means, and latches the plurality of parallel signals to obtain a plurality of latch signals. A delay means for generating a spread code, a spread code generating means for generating a spread code, and a delay code for delaying the spread code with a plurality of different delay times. Means, multiplying the plurality of latch signals and the plurality of delay spread codes to generate a plurality of delay spread signals, and multiplexing a signal based on the plurality of delay spread signals as a transmission signal And transmission signal output means for outputting and latch control means for generating a plurality of latch control signals each having the same timing as the start chip of the corresponding delay spread code. The latch means includes a plurality of latch control signals,
The plurality of parallel signals are latched, whereby the timings of the plurality of latch signals multiplied by the multiplication unit and the timings of the plurality of delay spread codes match, and the plurality of different delay times are mutually different. A spread spectrum communication system having an arbitrary time difference of 1 chip or more. 5. The transmitting means further includes a differential encoding means for performing differential encoding of the data string, the differential encoding means being provided in a stage before the serial / parallel converting means, The serial / parallel conversion means receives the differentially encoded data string, the reception means includes demodulation means for demodulating based on the received transmission signal, and the demodulation means includes a signal based on the transmission signal. Differential decoding means for performing differential decoding to generate a differential decoded signal by using, and integrating means for integrating the differential decoded signal having a temporal spread within a predetermined time range. A spread spectrum communication system according to any one of claims 1 to 4, comprising: 6. The transmission means further includes first parallel / delay control means for setting the number of parallel signals and the plurality of different delay times according to the use environment. 4. The spread spectrum communication system according to any one of 1 to 4. 7. The transmitting means changes the data rate according to the content of the information to generate the data string, and the data generating means so that the symbol rate becomes constant regardless of the change of the data rate. The spread spectrum communication system according to any one of claims 1 to 4, further comprising a second parallel / delay control means for setting the number of the plurality of parallel signals and the plurality of different delay times. 8. The spectrum according to claim 1, wherein in the multiple multiplexed signals, the different delay times are set so that the time difference between the adjacent signals is constant. Spread communication system.