JPH06326686A - Communication equipment - Google Patents

Abstract

PURPOSE:To provide a parallel transmission direct spread spectrum communication equipment capable of suppressing the influence of noise and the increase of a hardware scale accompanying the increase of a parallel transmission number. CONSTITUTION:A transmission high-seed digital data series is divided into (n) data series by a demultiplexer 2 and distributed components generated from a carrier wave generation circuit 101 and distributed into (n) pieces by a carrier wave distribution circuit 102 are respectively PSK modulated by the inputted data series in respective PSK modulators 30a-30n.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication device used for digital data communication by a spread spectrum system,
In particular, the present invention relates to a communication device capable of suppressing the influence of noise and an increase in the scale of hardware accompanying the increase in the number of parallel transmissions.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram showing a configuration of a transmission side of a conventional communication apparatus. In the figure, 1 is an input terminal to which a transmission high-speed digital signal is input, and 2 is n transmission high-speed digital signals. , 3n are PSK modulators, 4a, 4b, ..., 4n are multipliers, 5a, 5b, ..., 5n are independent of each other. Carrier wave generation circuit composed of oscillators, 6a, 6b, ..., 6
, 7n are multipliers, 8a, 8b, ..., 8n are separate spread spectrum code generators, 9 is a synthesizer, and 10 is a spread spectrum wave after synthesis. This is the output terminal that

FIG. 8 is a block diagram showing the configuration of the receiving side of a conventional communication apparatus. In the figure, 11 is an input terminal for receiving a spread spectrum wave, 12 is a distributor,
, 13n are N despreaders using individual codes, 14a, 14b, ..., 14n are multipliers respectively, and 15a, 15b, ..., 15n are code phases using individual spreading codes. A code generator including an acquisition / synchronization circuit, 21a, 21b, ..., 21n is a BPF for extracting a despread narrow band signal, 16
, 16n are PSK demodulators, 17n, respectively.
a, 17b, ..., 17n are multipliers, 18a,
18n are carrier wave reproducing circuits, 19 is a multiplexer for multiplexing demodulated n low-speed data into one high-speed data, 20 is an output terminal for outputting demodulated high-speed data, 22a, 22b ,. 22n is a carrier wave 2
LPF for removing double high frequency components and forming waveform
Is.

Next, the operation will be described. In general, the wave S (t) spectrally spread by the direct spread method is represented by the following equation (1) as a PSK modulated wave. S (t) = A PN (t) d (t) sin (ωct + θ) (1) where A is amplitude, PN (t) is spreading code time series, and d
(t) is the time series of information data, and ωc and θ are the angular velocity and phase of the carrier, respectively.

PN (t) and d (t) are represented by ± 1, where data 0 corresponds to -1 and data 1 corresponds to +1. PN (t) has a data rate sufficiently higher than d (t), and the ratio Sp of the two data rates is called the spreading gain. The code length of the PN code, which is often used as a spreading code, is chosen to be equal to Sp. For example, d (t) is 8
Assuming that the data rate is Kbps, assuming that the PN code length is 1023, the data rate of PN (t) (called a chip rate) is 8 Kbps × 1023 = 8.184 Mbps.
Becomes Further, at this time, the required bandwidth of S (t) shown in the equation (1) is normally selected to be twice the chip rate of PN (t), so in the above example, 8.184 × 2 = 16.368 MH
A z band is required.

Incidentally, in actual communication, it is often necessary to increase the data rate of d (t) while keeping the transmission band of S (t) constant. In such a case, the simplest is to reduce the spreading gain Sp. For example, if Sp = 511 in the above example, d (t) of about 16 Kbps can be transmitted. However, if such a method is used, the spreading gain Sp is halved and deteriorated by 3 dB, which is not preferable because the interference wave removing capability is reduced accordingly. In such a case, a method of dividing d (t) into a plurality of data sequences, subjecting them to spread spectrum modulation with individual different codes, combining them, and transmitting, that is, a parallel transmission direct spread spectrum spread method has been conventionally used. It was In this method, d (t) = 16
2 Kbps data series da (t), d of 8 Kbps
It is divided into b (t) and individual codes PNa (t) and P
Nb (t) (Chip rate is 8.184Mbp each
s) is assigned and transmission is performed. The spread spectrum wave S '(t) after synthesis at this time is expressed by the following equation (2). S ′ (t) = A PNa (t) da (t) sin (ωcat + θa) + A PNb (t) db (t) sin (ωcbt + θb) (2) In equation (2), ωca≈ωcb, PNa (t) , PNb (t) has a code length of 1023, and PNa (t) and da (t), PN
The ratio of the data rates of b (t) and db (t) is 1023, and although the information can be transmitted twice (16 Kbps), the spreading gain Sp is 1023 and the required band is 8K.
bps × 1023 × 2 = 16.368 MHz,
8 kbps can be transmitted in the same required band as in the case of transmission by the formula (1).

The conventional communication device shown in FIGS.
The data transmission is performed by such a parallel transmission direct spread spectrum spread method, and the operation by this parallel transmission direct spread spectrum spread method will be described below with reference to FIGS.

First, the transmitting side will be described with reference to FIG. In FIG. 7, transmission digital data (data rate is assumed to be u bps) input to the terminal 1 is transmitted by the demultiplexer 2 at equal speeds of n lines (data rate: u / n bp).
s) digital data. These n data series (each data series is da (t), db (t), ..., d
Notated as n. ) Is a multiplier 4a, 4b, ...,
4n and carrier wave generating circuits 5a, 5b, ..., 5n are used to provide PSK by PSK modulators 3a, 3b ,.
It is SK modulated. Here, each PSK modulator 3a, 3b,
The output of 3n is Ada (t) sin (ωcat + θa)
), Adb (t) sin (ωcbt + θb), ..., Adn (t) s
It is represented as in (ωcnt + θn) (where ωca, ωc
b,…, ωcn are almost equal).

Next, each of these outputs is sent to the multiplier 7
a, 7b, ..., 7n and spreading code (PNa (t)
, PNb (t), ..., PNn (t) generators 8a, 8b,
, 8n and spread spectrum devices 6a, 6b,
…, 6n diffused, APNa (t) da
(t) sin (ωcat + θa), APNb (t) db (t) sin (ω
cbt + θb), ..., APNn (t) dn (t) sin (ωcnt +
θ n). The spectrum spreader output is combined by the combiner 9 and is output from the terminal 10 as a wave of the following equation (3). APNa (t) da (t) sin (ωcat + θa) + APNb
(t) db (t) sin (ωcbt + θb) + ... + APNn (t) d
n (t) sin (ωcnt + θn) (3) Next, the receiving side will be described with reference to FIG.

The received wave input to the terminal 11 in the state where the transmission line noise is added to the output of the spectrum spreader of the above formula (3) is divided into n by the distributor 12, and the multiplier 14 respectively
, 14n and despreaders 13a, 13b, ..., 13n composed of code phase supplement / synchronization circuit circuits 15a, 15b ,.
SK modulated wave Ada (t) sin (ωcat + θa), Adb (t)
sin (ωcbt + θb), ..., Adn (t) sin (ωcnt + θn
), And then da (t), db (t), ..., d
BPFs 21a, 21b having a band similar to that of n (t),
The noise is removed by 21n. Here, the code phase supplement / synchronization circuit circuits 15a, 15b, ..., 15n capture the code phase and maintain synchronization with respect to their respective spreading codes. Then, the BPFs 21a, 21b,
The output from 21n is the PSK demodulator 16a, 1
Data is demodulated by 6b, ..., 16n into demodulated data da (t), db (t), ..., dn (t), which are multiplexed by the multiplexer 19 to form the original high-speed sequence d (t). It is output from 20. PSK demodulators 16a, 16
, 18n, 18a, 18b, ..., 18n
Is a carrier wave reproducing circuit for reproducing a carrier wave from an input PSK wave, and a Costas loop or the like is well known.
Further, 22a, 22b, ..., 22n are LPFs, which are provided for removing a high frequency component of twice the carrier wave and for shaping the waveform.

[0011]

As described above, in a communication apparatus for performing data communication by the conventional parallel transmission direct spread spectrum spread method, n carrier generation circuits are required on the transmission side, and the reception side is generally required. Since n carrier wave regenerating circuits that increase the hardware scale are required, the hardware scale increases as the number of parallel transmissions n increases, and the apparatus becomes very expensive.

Further, when the above communication device is used for a non-linear transmission line such as sanitary communication, the influence of intermodulation noise increases, and the carrier-to-noise ratio (carrier power / intermodulation component power) deteriorates. was there.

The present invention has been made to solve the above problems, and provides a communication device capable of suppressing an increase in hardware scale and a deterioration in carrier-to-noise ratio due to an increase in the number n of parallel transmissions. The purpose is to

[0014]

In the communication device according to the present invention, the distribution component of the carrier generated from one carrier generating circuit is PSK-modulated on the transmitting side by a plurality of data sequences divided by the demultiplexer. In this configuration, the receiving side is configured to demodulate a plurality of PSK modulated waves by the distribution component of the carrier waves reproduced by one carrier wave reproducing circuit.

Further, the communication apparatus according to the present invention is arranged such that the transmitting side is configured to spread a plurality of data sequences divided by the demultiplexer into spectrums for each data sequence, and to combine the plurality of spread output composite waves into one unit. Is configured so that the output carrier generated from the carrier generating circuit is AM-modulated, and the receiving side is configured to demodulate a plurality of PSK modulated waves by the distribution component of the carrier reproduced by each one carrier reproducing circuit. It was done.

Further, in the communication device according to the present invention, the plurality of spreading codes used for spread spectrum on the transmitting side have a constant phase relationship, and the receiving side captures one of the plurality of spreading codes. For other codes, the code is acquired by acquiring the code phase based on the above-mentioned fixed phase relationship.

Further, in the communication apparatus according to the present invention, on the transmission side, a plurality of data sequences divided by the demultiplexer are spectrum-spread by a modulo-2 adder for each data sequence, and these plurality of spread outputs are combined. The output carrier generated from one carrier generating circuit is configured to be AM-modulated, and the receiving side is connected to a plurality of P's.
The SK modulated wave is configured to be demodulated by the distribution component of the carrier wave reproduced by each one carrier wave reproduction circuit.

[0018]

According to the present invention, the number of carrier wave generating circuits on the transmitting side is one and the number of carrier wave regenerating circuits on the receiving side is one, so that the hardware scale of the transmitting side and the receiving side can be reduced.
Further, since the angular velocity of the carrier wave is the same for each data series, the influence of the intermodulation product component on the signal wave can be reduced.

Further, in the present invention, since the number of circuits mainly composed of analog circuits can be reduced, the hardware scale of the transmitting side and the receiving side can be further reduced, and the stability and reliability of the apparatus can be further improved. You can

Further, in the present invention, the code acquisition circuit on the transmission side is made one, and the plurality of spreading codes have a fixed phase relationship. Therefore, the hardware scale on the transmission side can be further reduced, and further, the reception side can Since the false acquisition rate in code acquisition can be reduced, the S / N ratio after despreading can be increased.

Further, in the present invention, all circuits except the AM modulator can be constructed by digital circuits,
The hardware scale of the transmitting side and the receiving side can be further reduced,
The stability and reliability of the device can be further improved.

[0022]

EXAMPLES Example 1. 1 and 2 are block diagrams respectively showing configurations of a transmitting side and a receiving side of a communication device which performs data transmission by a parallel transmission direct spread spectrum spread system according to a first embodiment of the present invention. Figure 7
30a, the same reference numerals denote the same or corresponding parts.
30n are PSK modulators, 101 is all P
A carrier wave generation circuit common to the SK modulators 30a, 30b, ..., 30n, and 102 is a carrier wave distribution circuit. Also, FIG.
8, 160a, 160b, ..., 160n are PSK demodulators, 201 is all PSK demodulators 160a, 160b,
, 160n is a common carrier wave reproducing circuit, and 202 is a reproduced carrier wave distributing circuit.

Next, the operation will be described. First, in FIG. 1 showing the transmitting side, the process up to the point where the transmission digital data input to the terminal 1 is divided into n constant velocity data by the demultiplexer 2 is the same as in FIG. 7 of the conventional example, but the PSK modulation after that is performed. Is a common carrier generation circuit 10
1 generated and distributed by the carrier distribution circuit 102,
This is performed by carrier waves that are in phase with all multiplier (4a, 4b, ..., 4n) inputs. The subsequent operation is also the same as in FIG. As a result, the output signal obtained from the terminal 10 is the common carrier signal Asin (ωct +
It will be expressed by the following equation (4) using θ). A [PNa (t) da (t) + PNb (t) db (t) + ... + PNn (t) dn (t)] × sin (ωct + θ) (4) Next, in FIG. 2 showing the receiving side, The code acquisition / synchronization is the same as that of the conventional example shown in FIG.
In the SK demodulator, the carrier recovery circuit 201 is one, and the output of the BPF 21a is the carrier recovery circuit 2
The carrier wave is regenerated at 01, and the regenerated carrier wave is distributed circuit 202 at each PSK demodulator 160a, 160b, ...
The PSK demodulators 160a, 16 are distributed every 160n.
The outputs from 0b, ..., 160n are multiplexed by the multiplexer 19 and output from the terminal 20. The above operation is possible by sharing the carrier wave on the transmitting side as shown in the equation (4). Further, here, the carrier wave is reproduced from the output of the BPF 21a,
The same applies regardless of the output of the BPF 21b, ..., 21n.

By the way, in a communication system for performing data communication through a non-linear transmission line, such as a sanitary communication using a non-linear amplifier for the earth station transmitter and the sanitary repeater,
It is known that intermodulation product components are generated when two or more carrier waves are simultaneously input to a non-linear transmission line ("Kazuhiro Miyauchi, Kunifumi Nosaka" published "Digital Sanitary Communication" Sangyo Tosho Co., Ltd., See pages 68-69.). Figure 7,
When the conventional communication device shown in FIG. 8 is applied to such a communication system, the angular velocity of the carrier wave (ωc
a, ωcb, ωcc) are slightly different from each other, a part of the intermodulation product components becomes an interference wave of the original data signal to be transmitted, which deteriorates the carrier-to-noise ratio. In the above, since the angular velocities (ωca, ωcb, ωcc) of the carrier waves for each data series are in the relationship of ωca = ωcb = ωcc = ω, it is possible to reduce such a problem that the carrier-to-noise ratio is deteriorated. .

In the communication apparatus of this embodiment, since the number of carrier generation circuits 101 on the transmission side is one and the number of carrier recovery circuits 201 on the reception side is one, the conventional parallel transmission direct spread spectrum spread system is used. As a result, it is possible to reduce the hardware scale as compared with a communication device that performs data communication, and it is possible to realize downsizing and cost reduction of the device.
Further, when applied to a communication system for performing data communication through a non-linear transmission line such as sanitary communication, the influence of intermodulation noise can be reduced as compared with the conventional case.

Example 2. FIG. 3 is a block diagram showing a configuration of a transmitting side of a communication device which performs digital data communication by a parallel transmission direct spread spectrum spread system according to a second embodiment of the present invention. In the figure, the same symbols as those in FIG. 7 are the same or equivalent. In the figure, 301 is a synthesizer, 302 is A
An M modulator 303 is a carrier wave generation circuit.

In the communication device of the first embodiment shown in FIG. 1 described above, the transmitting side is configured to combine the spread spectrum waves in the IF band, but in the communication device of the present embodiment, the communication device of FIG.
, The output of the demultiplexer 2 is first spectrum-spread by the spectrum spreaders 6a, 6b, ..., 6n, then these are combined by the combiner 301, and finally the common carrier generation circuit. The output carrier from 303 is AM-modulated by the AM modulator 302. Here, the output of the combiner 301 is expressed by the following equation (5), and PNa (t) da (t) + PNb (t) db (t) + ... + PNn
(t) dn (t) (5) By this output, the carrier signal Asin (ωct + θ) is AM
Modulation yields equation (4).

In the communication device of this embodiment, the receiving side has the same structure as that of the first embodiment.

In the communication device of this embodiment as well, since the transmission side carrier wave generation circuit and the reception side carrier wave recovery circuit can be respectively provided, the same effect as that of the communication device of the first embodiment can be obtained. You can Further, in FIG. 1 showing the configuration of the transmission side of the communication apparatus of the above-mentioned Embodiment 1,
The PSK modulators 3a, 3b, ... 3n and the spread spectrum devices 6a, 6b, .. 6n need to be mainly composed of analog circuits, and therefore labor is required for each level adjustment, phase adjustment, etc. Further, although there is a problem in stability and reliability due to temperature / aging, in the communication device of the present embodiment,
Since the number of circuits mainly including such analog circuits can be reduced, the hardware scale can be reduced, and the stability and reliability of the device can be improved.

Example 3. 4 is a block diagram showing a configuration of a transmitting side of a communication device which performs digital data communication by a parallel transmission direct spread spectrum spread system according to a third embodiment of the present invention. In the figure, the same symbols as those in FIG. 3 are the same or equivalent. , 401a, 401b, ..., 4
01n is a modulo-2 adder, 402 is a digital adder, and 403 is a D / A converter.

In the communication apparatus of the first embodiment shown in FIG. 1 described above, the transmitting side is configured to combine the spread spectrum waves in the IF band, but in the communication apparatus of the present embodiment, the configuration of FIG.
As shown in FIG. 5, the transmission side is configured such that the output of the demultiplexer 2 is first modulo-2 adders 401a, 401b ,.
After spectrum spreading at 401n, these are added by the digital adder 402, and the output is added to the D / A converter 4
After being converted into an analog value by 03, the AM modulator 302 is configured to AM-modulate the output carrier wave of the carrier wave generation circuit 303. Incidentally, the digital signal is represented as 1 or 0 here.

In the communication device of this embodiment, the receiving side has the same structure as in the first embodiment.

In the communication device of this embodiment as well, since the transmission side carrier wave generation circuit and the reception side carrier wave recovery circuit can be respectively one, the same effects as those of the communication device of the first embodiment can be obtained. Moreover, in the communication device of this embodiment, all circuits except the AM modulator 302 can be configured by digital circuits, so that the hardware scale can be further reduced, and the stability and reliability of the device can be further improved. You can

Example 4. 5 and 6 show Embodiment 4 of the present invention.
FIG. 6 is a block diagram showing respective configurations of a transmitting side and a receiving side of a communication device that performs data transmission by parallel transmission direct spread spectrum spread method by means of FIG. 5, and the same symbols in FIG. 5 as those in FIG. 3 indicate the same or corresponding portions. , 501a, 5
01b, ..., 501n are spread spectrum code generators, which are controlled so that their respective phases have a constant relationship. 6, the same reference numerals as those in FIG. 2 indicate the same or corresponding portions, 502a is a code acquisition / synchronization circuit, and 503b, ..., 503n are code synchronization circuits.

In the communication apparatus of this embodiment, the spread spectrum code generators 501a and 501 on the transmitting side shown in FIG.
01b, ..., 501n are controlled so that the phases of the respective codes have a constant relationship. That is, the code phase of the code generator 501a is set to the code generator 501b,
.., 501n to keep the phase relationship constant. On the other hand, on the receiving side shown in FIG. 6, the code acquisition is performed only by the code acquisition / synchronization circuit 502a, the code acquisition is not performed by the code synchronization circuits 502b, ..., 502n, and the code acquired by the code acquisition / synchronization circuit 502a. , 502n, the phase is loaded into the code synchronization circuits 502b, ..., 502n, and the code acquisition circuit for the codes b, ..., N is omitted from the configuration on the receiving side shown in FIG.

Therefore, in the communication apparatus of this embodiment, for example, when the code acquisition circuit is configured by a digital matched filter or the like, the hardware scale becomes large, but the code acquisition circuit on the receiving side is reduced to one. As a result, the hardware scale can be further reduced, and further downsizing and cost reduction of the device can be realized as compared with the device of the third embodiment. In addition, since the phase relationship of each code can be made constant on the receiving side, by pre-setting this phase relationship to a phase relationship that reduces the cross-correlation (interference) between each code, it is possible to prevent errors in code acquisition. The acquisition probability can be reduced, and the S / N of the signal wave after despreading
It enables highly reliable communication with a high ratio. On the receiving side, code division multiple access (CDMA) is possible by making all the codes the same and changing the phase relationship of the codes. In general, an autocorrelation function such as an M sequence is close to 0 when the phase is offset, so that code division multiple access (CDMA) with very little correlation between codes can be realized. It is also possible to reserve the type of code used.

[0037]

As described above, according to the present invention, the distribution component of the carrier generated from one carrier generating circuit is PSK-modulated on the transmitting side by the plurality of data sequences divided by the demultiplexer. On the receiving side, a plurality of PSK modulated waves are demodulated by the distribution components of the carrier waves reproduced by the single carrier wave reproducing circuit, so that the hardware scale of the transmitting side and the receiving side is reduced, and the device is reduced. Since the size and cost are reduced and the angular velocity of the carrier wave is the same for each data series, the influence of the intermodulation product component on the signal wave can be reduced, and the carrier-to-noise ratio can be improved.

Further, according to the present invention, on the transmitting side, a plurality of data sequences divided by the demultiplexer are subjected to spectrum spreading for each data sequence, and a single composite wave of a plurality of spread outputs is obtained. Since the output carrier generated from the carrier generating circuit is AM-modulated, and on the receiving side, a plurality of PSK modulated waves are demodulated by the distribution component of the carrier reproduced by each one carrier reproducing circuit, The number of circuits mainly composed of analog circuits can be reduced, the hardware scale of the transmitting side and the receiving side can be further reduced, and the stability and reliability of the device can be further improved.

Further, according to the present invention, the number of code acquisition circuits on the transmission side is one, and the plurality of spreading codes have a fixed phase relationship, so that the hardware scale on the transmission side can be further reduced and the reception side can be further reduced. Since the erroneous acquisition rate in the side code acquisition is reduced, the S / N ratio after despreading can be increased, and the reliability of the device can be further improved.

Further, according to the present invention, on the transmitting side, a plurality of data sequences divided by the demultiplexer are spectrum-spread by the modulo-2 adder for each data sequence, and a plurality of these spread outputs are combined. Thus, the output carrier generated from one carrier generating circuit is AM-modulated, and at the receiving side, a plurality of PSK modulated waves are demodulated by the distribution component of the carrier reproduced by each one carrier reproducing circuit. ,
All circuits except the AM modulator can be configured by digital circuits, and the hardware scales of the transmitting side and the receiving side can be further reduced, and the stability and reliability of the device can be further improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a transmission side of a communication device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a receiving side of the communication device according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a transmission side of a communication device according to a second embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a transmission side of a communication device according to a third embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a transmitting side of a communication device according to a fourth embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a receiving side of a communication device according to a fourth embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of a transmission side of a conventional communication device.

FIG. 8 is a block diagram showing a configuration of a receiving side of a conventional communication device.

[Explanation of symbols]

1 Input Terminal 2 Demultiplexer 3a to 3n PSK Modulator 4a to 4n Multiplier 5a to 5n Carrier Generation Circuit 6a to 6n Spread Spectrum Generator 7a to 7n Multiplier 8a to 8n Spread Spectrum Code Generator 9 Combiner 10 Output Terminal 11 Input Terminal 12 Distributor 13a to 13n Despreader 14a to 14n Multiplier 15a to 15n Code generator including code phase acquisition / synchronization circuit 16a to 16n PSK demodulator 17a to 17n Multiplier 18a to 18n Carrier recovery circuit 19 Multiplexer 20 Output Terminals 21a to 21n BPF 22a to 22n LPF 30a to 30n PSK modulator 101 Carrier generation circuit 102 Carrier distribution circuit 160a to 160n PSK modulator 201 Carrier reproduction circuit 202 Regenerated carrier distribution circuit 301 Combiner 302 AM modulation 303 carrier output 401a~401n modulo-2 adder 402 digital adder 403 D / A converter 501a~501n spread spectrum code generator 502a code acquisition / synchronization circuit 502b~502n code synchronization circuit

[Procedure amendment]

[Submission date] August 17, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 3

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

The received wave input to the terminal 11 in the state where the transmission line noise is added to the output of the spectrum spreader of the above formula (3) is divided into n by the distributor 12, and the multiplier 14 respectively
, 14n and despreaders 13a, 13b, ..., 13n composed of code phase supplement / synchronization circuit circuits 15a, 15b ,.
SK modulated wave Ada (t) sin (ωcat + θa), Adb (t)
sin (ωcbt + θb), ..., Adn (t) sin (ωcnt + θn
), And then da (t), db (t), ..., d
BPFs 21a, 21b having a band similar to that of n (t),
The noise is removed by 21n. Here, the code phase acquisition / synchronization circuitry 1 5a, 15b, ..., 15n performs acquisition and synchronization maintenance of code phase for each of the unique spreading codes. Then, the BPFs 21a, 21b, ..., 2
The output from the 1n is the PSK demodulators 16a, 16b,
The data is demodulated by 16n and demodulated data da
(t), db (t), ..., Dn (t), which are multiplexed by the multiplexer 19 to form the original high-speed sequence d (t), which is output from the terminal 20. PSK demodulators 16a, 16b,
, 16n, 18a, 18b, ..., 18n are carrier wave reproducing circuits for reproducing a carrier wave from an input PSK wave, and a Costas loop or the like is well known. Further, 22a, 22b, ..., 22n are LPFs, which are provided for removing a high frequency component of twice the carrier wave and for shaping the waveform.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

[0012] In the case of using the communication device to a non-linear transmission path such as satellite communications, the influence of the intermodulation noise is increased, a problem that carrier-to-noise ratio (power carrier power / intermodulation component) is degraded There was a point.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

Furthermore, in this invention, since a plurality of spreading codes in a fixed phase relationship on the transmission side, the reception side co
Can turn over de acquisition circuit into one, it can more reduce the hardware scale of receiving side, moreover, since it can reduce the acquisition rate false in the code capture the receiving side, to increase the S / N ratio after despreading it can.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0024

[Correction method] Change

[Correction content]

By the way, in the communication system that the earth station transmitter and satellite repeaters, such as satellite communication using a non-linear amplifier, performs data communication with a nonlinear transmission path,
When two or more waves of the carrier wave are simultaneously input to the nonlinear transmission path, the intermodulation products components of generating a known ( "Kazuhiro Miyauchi, Nosaka Kunishi co" digital satellite communications "Sangyo Tosho published , 68-69 "). Figure 7,
When the conventional communication device shown in FIG. 8 is applied to such a communication system, the angular velocity of the carrier wave (ωc
a, ωcb, ωcc) are slightly different from each other, a part of the intermodulation product components becomes an interference wave of the original data signal to be transmitted, which deteriorates the carrier-to-noise ratio. In the above, since the angular velocities (ωca, ωcb, ωcc) of the carrier waves for each data series are in the relationship of ωca = ωcb = ωcc = ω, it is possible to reduce such a problem that the carrier-to-noise ratio is deteriorated. .

[Procedure correction 6]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

In the communication apparatus of this embodiment, since the number of carrier generation circuits 101 on the transmission side is one and the number of carrier recovery circuits 201 on the reception side is one, the conventional parallel transmission direct spread spectrum spread system is used. As a result, it is possible to reduce the hardware scale as compared with a communication device that performs data communication, and it is possible to realize downsizing and cost reduction of the device.
Also, when applied to a communication system for performing data communication with a non-linear transmission path such as satellite communication, compared to the prior art, to reduce the effect of intermodulation noise.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0036

[Correction method] Change

[Correction content]

Therefore, in the communication apparatus of this embodiment, for example, when the code acquisition circuit is configured by a digital matched filter or the like, the hardware scale becomes large, but the code acquisition circuit on the receiving side is reduced to one. As a result, the hardware scale can be further reduced, and further downsizing and cost reduction of the device can be realized as compared with the device of the third embodiment. Also, the transmit side, since the phase relation of each code can be made constant, by previously setting the phase relationship correlation (interference) becomes smaller as a phase relationship between the code in the code capture erroneous capture probability can be reduced, also the signal wave after despreading S
Highly reliable communication with an improved / N ratio becomes possible. Also,
In transmit side, all of the code the same, only varying the phase relationship of the code, code division multiple access (CDMA)
Is possible. In general, an autocorrelation function such as an M sequence is close to 0 when the phase is offset, so that code division multiple access (CDMA) with very little correlation between codes can be realized. It also makes it possible to save the types of codes used.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0039

[Correction method] Change

[Correction content]

[0039] Furthermore, according to the present invention, since the spreading codes of multiple transmit side in a constant phase relationship, of the reception side
Can code acquisition circuit into one, with a hardware scale of receiving side can be more reduced, it is possible to reduce the acquisition error rates in the code capture the receiving side, also despread S /
The N ratio can be increased, and the reliability of the device can be further improved.

Claims (4)

[Claims] 1. A communication device for performing digital data communication by parallel transmission direct sequence spread spectrum method, wherein a transmitting side thereof parallelizes a transmission high-speed digital data sequence into n low-speed data sequences, and said n number of demultiplexers. N is provided for each data series of the low-speed data series, and PSK-modulates the distribution component of the carrier wave generated from one carrier wave generation circuit by the input low-speed data series.
N PSK modulators and n spectrums provided for each output of the above n PSK modulators and spread spectrum of the input PSK modulator outputs by direct spread method by n different spread codes. It consists of a spreader and a combiner that combines the outputs of the n spread spectrum devices. The receiving side of the spreader divides the input spread spectrum wave into n distributors, and the n distributors distributed by the distributor. Of the spread spectrum wave of each of the spread spectrum waves, and the input spread spectrum wave is de-spread by performing code acquisition / synchronization by n different spreading codes used on the transmitting side. A despreader, a carrier recovery circuit that receives an output from any one of the n despreaders and reproduces a carrier wave, and a carrier recovery circuit that reproduces the carrier wave by the one carrier reproduction circuit. The n despreader output signals are respectively P
A communication device comprising: n PSK demodulators for SK demodulation; and a multiplexer for serially converting output demodulated data sequences of the n PSK demodulators. 2. A communication device for performing digital data communication by parallel transmission direct spread spectrum spread system, wherein the transmitting side of the communication device performs parallel conversion of a transmission high-speed digital data sequence into n low-speed data sequences, and the above n lines of demultiplexers. Provided for each data sequence of the low-speed data sequence are n spectrum spreaders that directly spread spectrum the input low-speed data sequence with n different spreading codes, and the outputs of the n spectrum spreaders. It is composed of a synthesizer for synthesizing and an AM modulator for AM-modulating an output carrier generated from one carrier generating circuit by the output of the synthesizer, and the receiver side distributes the input spread spectrum wave to n. And a spreader wave for each of the n spread spectrum waves distributed by the distributor, Either of the n despreaders for performing despreading by performing code acquisition / synchronization on the spread spectrum wave by the n different spreading codes used on the transmitting side, and the n despreaders. One carrier recovery circuit for receiving one output and reproducing it as a carrier, and the n despreader output signals by the distribution component of the carrier reproduced by the one carrier recovery circuit, respectively.
A communication device comprising: n PSK demodulators for SK demodulation; and a multiplexer for serially converting output demodulated data sequences of the n PSK demodulators. 3. The communication device according to claim 2, wherein the n spread spectrum devices on the transmission side are configured such that the phase relationships of the n spread codes are constant. The despreader captures a specific one of the n conversion codes, and the other remaining conversion codes acquire the code phase based on the constant phase relationship. A communication device characterized by being configured to be captured by the above. 4. A communication device for performing digital data communication by parallel transmission direct spread spectrum spread method, wherein the transmission side of the demultiplexer converts the transmission high-speed digital data sequence into n low-speed data sequences in parallel, and the above n lines. The modulo-2 adder is provided for each data sequence of the low-speed data sequence, and spreads the input low-speed data sequence with n different spreading codes, and outputs of the n-modulo-2 adders are output. An AM modulator that adds an adder, a D / A converter that converts the output of the adder into an analog value, and an output carrier generated from one carrier generation circuit by the output of the D / A converter. And a receiver for dividing the input spread spectrum wave into n pieces, and n pieces of pieces divided by the above-mentioned divider. N inverse spreads, which are provided for each spread spectrum of the spectrum spread waves, perform despreading by performing code acquisition / synchronization on the input spread spectrum waves by n different spreading codes used on the transmitting side. A spreader, a carrier reproduction circuit for receiving an output from any one of the n despreaders and reproducing the carrier wave, and a distribution component of the carrier reproduced by the one carrier reproduction circuit for the n carrier waves. Despreader output signals are
A communication device comprising: n PSK demodulators for SK demodulation; and a multiplexer for serially converting output demodulated data sequences of the n PSK demodulators.