JPH11122215A - Communication system by interference elimination method between multiplexed position modulation signals - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the communication system that solves a problem of missing pulse in multiplexing used for position modulation of both positive negative pulses of each entire data frame and high speed transmission with a high efficiency is attained. SOLUTION: A set of pluralities of multi-value data symbols Si (S1 ...SM) where each symbol takes multi-values are converted into a set of pluralities of coded data symbols S'i (S'1 ...S'N) which correspond one to one to the data symbols Si (S1 ...SM) and take different values according to a prescribed coding rule, positions of pulses are modulated by a multiplex pulse position modulation system modulation section, multiplexed and sent to a transmission line. A multiplex pulse position modulation system demodulation section at a receiver side recover each of coded data symbols S'i (S'i ...S'N) and a demodulation means decodes a set of the original multi-value data symbols Si according to a decoding rule inverse to the coding rule. Since pluralities of the coded data symbols S'i take different values, the overlapping of pulses is eliminated at multiplexing to eliminate a transmission error.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to wireless data communication,
The present invention relates to a pulse position modulation method or a spread spectrum pulse position modulation method used for wireless LAN and optical communication, and more particularly to a technique for eliminating interference between signals when multiplexing and transmitting a modulated signal according to the method.

[0002]

2. Description of the Related Art A conventional technique relating to a spread spectrum pulse position modulation method is disclosed in Japanese Patent Laid-Open No. 8-79133 as "a method and apparatus for spectrum code pulse position modulation". According to the present invention, since two orthogonal carriers are used to multiplex the spread spectrum pulse position modulation signal, only two position modulation pulses can be transmitted in one data frame.

Further, in the invention disclosed in Japanese Patent Application No. 8-151917 as "spread spectrum pulse position modulation communication system", two multiplexed signals are discriminated by discriminating two spread spectrum pulse position modulation signals by the sign of the pulse code. Since quadrature multiplexing can be performed by using orthogonal carriers in combination, the speed can be further increased as compared with the conventional example. When the time positions of the positive and negative pulses match in each frame, the positive and negative pulses cancel each other out, and a problem arises in that the pulse position modulated wave cannot be demodulated normally. This will be described in more detail with reference to FIG. 1 (A). FIG. 1 (A) shows an output signal of a matched filter in the two-multiplexed spread spectrum pulse position modulation method, and shows two codes of two codes. This is the same signal obtained by superposing two different pulse position modulation signals. In FIG. 1A, each data frame of frames 1, 2,... Is composed of 10 slots, of which 8 (corresponding to data symbol values 0 to 7) are data slots used for position modulation. Here is an example. In addition,
8, 9 slots are used as guard slots. If the first data symbol is represented by S _{1 (P)} and the second data symbol is represented by S _{2 (P)} , in frame 1, S _{1 (P)} =
0, S _{2 (P)} = 4 and the values are different, so that two positive and negative position modulation pulses are correctly generated.
In this case, since S1 _(P) = 5 and S2 _(P) = 5 and the values are the same, the positive and negative pulses cancel each other out, so that the pulse disappears. Therefore, error-free data transmission cannot be performed as it is. To avoid this problem, Japanese Patent Laid-Open No.
In Japanese Patent No. 51917, each data frame is divided into two parts, one of which is used for position modulation of a positive peak, and the other is used for position modulation of a negative peak.

[0004]

However, if the problem of pulse erasure can be solved, the entire data frame can be used for position modulation of both positive and negative peaks, so that the number of transmission bits per frame can be increased. And more efficient high-speed transmission becomes possible. The present invention has been made in view of such a situation in the related art, and in a multiplexing technique in which the entire data frame can be used to modulate the positions of the peaks of both positive and negative pulses, the problem of pulse erasure is solved by improving the efficiency. It is an object of the present invention to provide a communication system that performs transmission and reception by a method that enables good high-speed transmission.

[0005]

According to a first aspect of the present invention, a predetermined pulse signal is temporally modulated in accordance with the data value of a multi-valued original data symbol, and a plurality of the obtained position-modulated pulse signals are converted. A communication system for transmitting and receiving a multiplexed position modulation pulse signal generated and multiplexed according to a multiplexing method for eliminating interference between multiplexed signals during multiplexing as a transmission signal, wherein each of the position modulation pulse signals to be multiplexed is A combination of coded data symbol values that take on different data values corresponding to each combination of a plurality of original data symbol values that are multiplexed with each other on the transmitting side so as not to overlap in time in accordance with a fixed coding rule. The position modulation and multiplexing are performed according to each coded data symbol value after the conversion, and each of the signals is separated from the multiplexed position modulation pulse signal received at the receiving side. For the position-modulated pulse signal, a combination of the plurality of encoded data symbol values having different data values is reproduced, and the combination of the reproduced plurality of encoded data symbol values is subjected to an operation reverse to the encoding rule. According to the decoding rule to be performed, the combination of the plurality of original data symbol values is decoded, and the original multi-valued original data symbol is reproduced.

According to a second aspect of the present invention, a pseudo-noise signal having a predetermined time length is temporally modulated according to the data value of a multi-valued original data symbol, and a plurality of the obtained position-modulated pseudo-noise signals are multiplexed. A spread-spectrum communication system for transmitting and receiving a multiplexed position-modulated pseudo-noise signal multiplexed and generated according to a multiplexing method for removing interference between multiplexed signals as a transmission signal, wherein the position-modulated pseudo-noise signal to be multiplexed is Each combination of a plurality of original data symbol values that are multiplexed on the transmitting side so that the correlation pulses after despreading do not overlap with each other is different from each other in a one-to-one correspondence with a fixed encoding rule. Is converted to a combination of coded data symbol values, and the position modulation and multiplexing are performed using the coded data symbol values after conversion. Despreads the position modulated pseudo noise signal,
Regenerating a combination of the plurality of encoded data symbol values having different data values for each separated correlation pulse signal, and combining the reproduced combination of the plurality of encoded data symbol values with a code inverse to the encoding rule. The method is characterized in that the combination of the plurality of original data symbol values is decoded according to a decoding rule for performing the operation, and the original multi-valued original data symbol is reproduced.

According to a third aspect of the present invention, in the communication system according to the first or second aspect, the coded data of the plurality of original data symbol values to be multiplexed on the transmission side. For the conversion into symbol values, the combination of coded data symbol values taking N different data values, which correspond to each other in one-to-one correspondence, with respect to all patterns of the M data symbol values to be multiplexed. Prepare a conversion table to output, and on the receiving side,
In order to convert the plurality of encoded data symbol values to the original data symbol values, a conversion table for performing an inverse conversion of the conversion table is prepared.

According to a fourth aspect of the present invention, in the communication system according to any one of the first to third aspects, the fixed coding used when the number of multiplexing is two, As a decoding rule, the transmitting side uses the value A of the first original data symbol as it is as the value of the first encoded data symbol, and uses the second value A of the second encoded data symbol as the value of the second encoded data symbol. When the relationship between the value B of the original data symbol and the value A of the first original data symbol is B ≧ A, (B + 1) is used, and when B <A, B is used. The value A of the first encoded data symbol demodulated as the value of the reproduced original data symbol is used as it is, and the value B 'of the second encoded data symbol demodulated as the value of the second reproduced data symbol Also (B'-1) is used when B'≥A, and B 'is used when B'<A, thereby eliminating temporal overlap of the multiplexed position modulation signals. .

According to a fifth aspect of the present invention, in the communication system according to any one of the first to third aspects, the fixed coding used when the number of multiplexing is two, As a decoding rule, the transmitting side uses the value A of the first original data symbol as it is as the value of the first encoded data symbol, and uses the second value A of the second encoded data symbol as the value of the second encoded data symbol. When the relationship between the value B of the original data symbol and the value of the first original data symbol is B = A, the specific value X is a value other than the possible value of A; otherwise, the same value as B is used. On the receiving side,
Using the value of the first demodulated encoded data symbol as it is as the value of the first reproduced original data symbol,
The value A is used when the value B 'of the second demodulated encoded data symbol matches X as the value of the second reproduced original data symbol, and the value B' is used otherwise. This is characterized in that temporal overlap of the pulse position modulation signal has been removed.

According to a sixth aspect of the present invention, in the communication system according to any one of the first to third aspects, the fixed coding used when the number of multiplexing is two, As a decoding rule, the transmitting side uses the value A of the first original data symbol as it is as the value of the first encoded data symbol, and uses the second value A of the second encoded data symbol as the value of the second encoded data symbol. Assuming that the value of the original data symbol is B, and that a certain value larger than the maximum possible value of A and B is M, the remainder obtained by dividing (A + B + 1) by (M + 1) is used. The value A of the first demodulated coded data symbol is used as it is as the value of the data symbol, and the value of the second demodulated coded data symbol is used as the value of the second original reproduced data symbol. 'With respect to (B' a + M-A) (M +
The method is characterized in that temporal overlap of the multiplexed pulse position modulation signal is removed by using the remainder value divided by 1).

According to a seventh aspect of the present invention, a predetermined pulse signal is temporally modulated in accordance with a data value of an original data symbol having a multi-level, and a plurality of obtained position-modulated pulse signals are subjected to signal A communication system for transmitting and receiving as a transmission signal a duplex position-modulated pulse signal that is duplicated and generated in accordance with a method for eliminating interference of a first original data symbol and a second original data symbol value on a transmission side during duplexing. Only when the values of the original data symbols are equal, one of the position modulation pulse signal outputs is set to zero, and only the other position modulation pulse signal is transmitted as a transmission signal. After separation into pulse signals, the missing pulse of the one position modulation pulse signal whose signal output is made zero is reproduced based on the other position modulation pulse signal transmitted normally, and reproduced. It is obtained is characterized in that for reproducing the original data symbols of the multi-level restore for each position modulated pulse signal.

According to the present invention, a pseudo-noise signal having a predetermined time length is temporally modulated according to the data value of an original data symbol having a multi-level, and a plurality of the obtained position-modulated pseudo-noise signals are duplicated. A spread-spectrum communication system for transmitting and receiving as a transmission signal a duplex position-modulated pseudo-noise signal that is duplicated and generated in accordance with a method of eliminating interference between signals when a first original data is transmitted on a transmission side when duplexing is performed. Only when the value of the symbol and the value of the second original data symbol are equal,
Either one is set to zero, the other position-modulated pseudo-noise signal is multiplied by a carrier wave and transmitted as a transmission signal. After performing a correlation operation with the above, the duplicated position modulation pulse signal is reproduced, and after separating from the duplicated position modulation pulse signal into each position modulation pulse signal, the missing pulse of the one position modulation pulse signal whose signal output is made zero is normal. And reproducing the multi-level original data symbol for each of the reproduced position-modulated pulse signals as before.

According to a ninth aspect of the present invention, there is provided a communication system according to any one of the first to eighth aspects, wherein the position modulation pulse signal or the position modulation pseudo noise signal is a position modulation signal. Is further multiplied by multiplying and adding a carrier having the same frequency and a different phase, and the receiving side separates each position modulation signal for each carrier phase, and then outputs each position modulation pulse. A multiplexing means for reproducing a data symbol from a signal is used.

According to a tenth aspect of the present invention, in the communication system according to the third aspect, the data set of the conversion table used for encoding on the transmission side and decoding on the reception side is transmitted to a terminal. A different data set is prepared for each receiver, and the transmitting side selects a data set matched with the conversion table held by the receiving side from the different data sets for each partner so that communication can be normally performed only with a specific receiver. , And has a function of encryption.

[0015]

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a pulse position modulated signal,
Alternatively, the present invention provides a communication system having means for removing mutual interference between multiplexed signals generated when multiplexing spread spectrum pulse position modulated signals and transmitting the signals in parallel, wherein the pulse position described in the section of the above [Prior Art] is provided. Problems that occur in the prior art in which a modulated signal is simply multiplexed (FIG. 1)
(A)).

In the present invention, therefore, there are roughly two methods for solving the problem and eliminating transmission errors.
The first method is to convert a plurality of multiplexed data symbols into different values corresponding to each other in a one-to-one correspondence according to a predetermined coding rule, so that multiplexed pulses in a frame temporally overlap with each other. It is to prevent that. On the receiving side, the original data symbols can be reproduced by performing decoding in the reverse operation of the encoding. As an example, as shown in FIG. 1B, when two data symbol values match in the case of duplexing, one data symbol value is replaced by a value that is not normally taken (slot 8 in the example shown), By setting a pulse at another position only when coincides, overlapping of a plurality of position modulation pulses can be avoided.

In the second method, only in the case of duplexing, when two data symbols have the same value, the output of the position modulation signal for one of the data symbols is set to zero to prevent the disappearance of the pulse. This is a method of reproducing the original data symbol by adding the interpolation function.

The invention of claim 1 forms a basic configuration of a communication system according to a first method (a method of moving overlapping pulses), and multiplexes and transmits a plurality of pulse signals position-modulated by multi-level data symbols. It is configured to include a method of removing interference between multiplexed signals used at the time. FIG. 2 shows an embodiment of a communication system according to this method.
As shown in FIG. 2, a multi-level data symbol S _i composed of a plurality of data symbols on the transmitting side, each of which can take multi-levels.
A set of (S ₁ ... S _M ) corresponding to a set of coded data symbols S ′ _i (S ′ ₁ ... S ′ _N ) consisting of a plurality of coded data symbols and having mutually different values. Conversion is performed in accordance with the coding rule to generate a set of coded data symbols S ′ _i (S ′ ₁ ... S ′ _N ) having different values from each other, and the multiplexed pulse position modulation type modulator modulates the set by using each coded data symbol value. A multiplexed pulse position modulation signal is generated and transmitted to a transmission path. On the receiving side, the received multiplexed pulse position modulation signal is input to the multiplexed pulse position modulation type demodulation unit, and the same encoded data symbols S ′ _i as those on the transmitting side are input.
(S ′ ₁ ... S ′ _N ) are reproduced, and a set of a plurality of reproduced encoded data symbols S ′ _i (S ′ ₁ ... S ′ _N ) is decoded by performing an operation opposite to the previous coding rule. The original multi-valued reproduced data symbol S
_i (S ₁ ... S _M ). As a result, overlapping of the multiplexed pulses can be removed, and transmission errors can be eliminated.

A second aspect of the present invention constitutes such a communication system by applying the first aspect of the present invention to a spread spectrum pulse position modulation communication system. It is configured to have an interference cancellation method between multiplexed signals used when a plurality of noise signals are multiplexed and transmitted. An embodiment of a communication system according to this method is shown in FIG. As shown in FIG. 3, a multi-valued data symbol S _i (S ₁ ... S _M ) consisting of a plurality of data symbols on the transmitting side, each of which can take multi-values.
Are composed of a plurality of coded data symbols, each having a different value from each other.
_i (S ′ ₁ ... S ′ _N ) are converted to correspond one-to-one according to a certain coding rule to generate coded data symbols S ′ _i (S ′ ₁ ... S ′ _N ) having different values. The multiplexed spread-spectrum pulse position modulation type modulator generates a multiplexed spread-spectrum pulse position modulation signal (SS-PPM signal) based on the coded data symbol value and sends it out to the transmission path. On the receiving side, the received multiplexed SS-PPM signal is input to the multiplexed spread spectrum pulse position modulation type demodulation unit, and the same coded data symbols S ′ _i (S ′ ₁ .
S ′ _N ) is reproduced, and a set of the reproduced coded data symbols S ′ _i (S ′ ₁ ... S ′ _N ) is subjected to a decoding rule that performs an operation opposite to the previous coding rule. By the decoding means, the original multi-valued reproduced data symbol S _i (S ₁ .
S _M ). As a result, even in the spread spectrum pulse position modulation communication system, the overlap of pulses at the time of multiplexing can be removed, and transmission errors can be eliminated. The spread spectrum position modulation type modulator is realized by generating a pseudo noise (PN) signal having a predetermined time length based on the output signal of the conventional pulse position modulation type modulator. The spread spectrum pulse position modulation system demodulation unit can be composed of a matched filter (matched filter) used in the conventional spread spectrum communication and a conventional pulse position modulation system demodulation unit, and passes the spread spectrum received signal through the matched filter. As a result, the pulse position modulation signal can be reproduced, and by inputting this to the conventional pulse position modulation type demodulation section, the encoded data symbol can be reproduced.

According to a third aspect of the present invention, an encoding / decoding conversion table using a memory or the like is used as a method of implementing the conversion means in the first or second aspect of the present invention. As a configuration, a conversion table for outputting a set of coded data symbols of N values different from each other in one-to-one correspondence with all combinations of M data symbol values to be multiplexed is provided on the transmission side. Prepared and multiplexed pulse position modulation is performed using the output N values as new encoded data symbol values for position modulation. Further, the receiving side separates each pulse position modulation signal from the received multiplexed signal, and then reproduces the encoded data symbols for each pulse position modulated signal. In this case, another conversion table for performing the reverse conversion of the previous conversion table is prepared to obtain the original M reproduced data symbols. Here, the number M of the original data symbols to be multiplexed and the value N of the number of encoded data symbols different from each other may be different.

FIG. 4 shows an embodiment of this means. In FIG. 4, on the encoding side in FIG.
Each data symbol values S _i is converted into binary data converter into an address value, either of the address input signals work Raku memory 1 that each bit as a conversion table by a ROM or RAM, and the output of the memory 1 It is made to correspond to the encoded data symbol values S _'i, each in several. Figure 4 encoded data symbol values S _'i conversion circuit to perform the address value in the same configuration decoding in the decoding side as shown in (B) is converted into the address to the memory 2. The only difference is the data in the memory 2 used as the conversion table. FIG. 5 shows an example of the data of the conversion tables in the memory 1 and the memory 2. This shows an example in which the number M of data symbols to be transmitted is 2, the number of multilevels is 4, and the number N of multiplexing in the position modulation section is 2, and after coding, the multilevel number of one symbol increases to 5. ing. As can be seen from FIG. 5, after encoding, no two data symbols take the same value.

According to a fourth aspect of the present invention, in the interference elimination system according to the first to third aspects of the present invention, a communication system which complies with a first rule of constant coding and decoding used when the number of multiplexing is two. FIG. 6 shows an embodiment thereof. As shown in FIG. 6, the coding phase of the transmission side, first as a first encoded data symbols S _'1 of value 1
The value of the data symbols S ₁ of using (a value to A) it is, as the second value of the coded data symbols S _'2, the second data symbol S ₂ value (a value to B) is When B ≧ A, B + 1 is used. In other cases, B is used. Then, in the decoding stage on the receiving side, the value of the first demodulated coded data symbol S ′ ₁ (value is A) is used as it is as the value of the first reproduced data symbol S ₁ , the value of the data symbols S _2,
If B ′ ≧ A based on the value of the second demodulated coded data symbol S ′ ₂ (the value is B ′), the value is B′−
1. In other cases, the original data symbol is reproduced without error by using a value of B '.
Since this rule is a simple rule, it can be easily formed into a circuit as shown in FIG. In FIG. 6, a comparator is used to compare two data symbol values A and B to generate a decision signal, and the output is added to one of the data symbol values to perform coding, and the subtraction is performed to perform decoding to subtract. Has been done.

According to a fifth aspect of the present invention, in the interference elimination system between multiplexed signals according to the first to third aspects, a communication system according to a second rule of constant coding and decoding used when the number of multiplexing is two. FIG. 7 shows an embodiment thereof. As shown in FIG. 7, in the encoding stage on the transmission side, the value of the first data symbol S ₁ (value is A) is used as it is as the value of the first encoded data symbol S ′ ₁ , When the value of the second data symbol S ₂ (the value is B) is B = A, the value of the _second encoded data symbol S ′ ₂ is a specific value X other than the value that A can take,
In other cases, the same value as B is used. Then, at the stage of decoding of the reception side, a first demodulated coded data symbols S as a first value of the reproduction data symbols S _{1 '1}
(The value is A) as it is, and as the value of the second reproduced data symbol S ₂ , the value (the value is B ′) of the second demodulated encoded data symbol S ′ ₂ becomes X If they match, the value is A, otherwise, the value is B '. Since this rule is a simple rule, FIG.
The circuit can be simply formed as shown in FIG. In FIG. 7, a decision signal is generated using a coincidence comparator to compare two data symbol values A and B, and one of the encoded data symbol values is used as an original value or a specific value X using the decision signal as a control signal. (It is set to a value other than the value that can be taken by the original data symbol) by the multiplexer to perform encoding,
At the time of decoding, a coded data symbol value and a specific value X are compared by a comparator, and when they match, the other coded symbol is selected by a multiplexer, so that decoding is performed as before.

According to a sixth aspect of the present invention, there is provided a communication system according to the first to third aspects of the present invention, which employs the third rule of constant coding and decoding used when the number of multiplexing is two in the interference elimination system between multiplexed signals. FIG. 8 shows an embodiment thereof. As shown in FIG. 8, in the coding stage on the transmitting side, the value of the first data symbol S ₁ (value is A) is used as it is as the value of the first coded data symbol S ′ ₁ , the second value of the coded data symbols S _'2, a second value of the data symbols S ₂ B, a larger maximum value is a possible value of the value a and value B as M, (a + B
(+1) divided by (M + 1) is used. Then, in the decoding stage on the receiving side, the value of the first demodulated coded data symbol S ′ ₁ (value is A) is used as it is as the value of the first reproduced data symbol S ₁ , As the value of the data symbol S _2, the value of the second demodulated encoded data symbol S ′ ₂ is B ′ (B ′ + M
−A) is divided by (M + 1) and the remainder is used. Since this rule is also a simple rule, it can be easily formed into a circuit as shown in FIG. In FIG. 8, the remainder arithmetic unit uses the values A and B of the two data symbols to obtain (A + B + 1) / (M
+1) is calculated to generate one encoded data symbol, and the receiving side calculates (B ') the remainder from the encoded data symbol and the value A of the other data symbol.
By calculating the remainder of (+ M−A) / (M + 1), decoding is performed as before.

According to a seventh aspect of the present invention, when the values of two data symbols are equal in the duplex pulse position modulation method, the output of the pulse position modulation signal for one data symbol is set to zero to prevent the disappearance of the pulse. Then, the interpolation function is added to reproduce the original data symbol.
FIG. 9 shows an embodiment of the present invention. As shown in FIG.
At the time of multiplexing, the value of the first data symbol S ₁ (value is A) and the value of the second data symbol S ₂ (value B) are compared by a comparator on the transmission side, and the two are equal. Only at the time, one of the modulation signals from the two pulse position modulation type modulation units 1 and 2 is set to zero by using a switch so that only the remaining pulse position modulation signal is transmitted. Then, on the receiving side, after separating each pulse position modulation signal from the multiplexed signal received by the multiplex signal separation unit, each is demodulated by the pulse position modulation type demodulation units 1 and 2 to reproduce data symbols, generates a pulse dropout signal by loss detecting unit reproduces the missing pulse by taking a logical product of the pulse position modulated signal for the first data symbol S ₁ towards which the signal missing has not occurred, the missing and this Play the pulse position modulated signal without missing the logical sum of the pulse position modulated signal for a second data symbol S _2, finally similar to the conventional multi-level data symbols by pulse position modulation scheme demodulator 2 By reproducing, data transmission without error is realized.

The invention of claim 8 is an adaptation of the invention of claim 7 to a spread spectrum pulse position modulation communication system, and an embodiment thereof is shown in FIG. As shown in FIG. 10, on the transmitting side, the pulse position modulation type modulation units 1 and 1 shown in FIG.
The spread spectrum pulse position modulation is performed by using the spread spectrum pulse position modulation method modulators 1 and 2 instead of 2. On the receiving side, since the received signal is spread, the pseudo-noise (P
N) It is necessary to prepare a matched filter for obtaining matching between the signal and the same signal, and to despread the received spread signal to reproduce the multiplexed pulse position modulation signal. By using the same receiver as that shown in FIG. 9, the invention of claim 7 can be applied to a spread spectrum pulse position modulation communication system.

According to a ninth aspect of the present invention, there is provided a method of multiplexing pulse position modulated signals by the interference elimination method between multiplexed signals according to the first to eighth aspects of the present invention. The present invention can be applied to a case where a method of multiplying a noise signal by a carrier having the same frequency but different phases and adding the same is adopted. Then, on the receiving side, discrimination is performed by the carrier phase for each pulse of the multiplexed pulse position (or spread spectrum pulse position) modulation signal, and a plurality of pulse position modulation signals are reproduced. The original data symbols can be reproduced by the pulse position modulation type demodulation unit, and the interference elimination method between multiplexed signals according to the first to eighth aspects of the present invention can be further applied. Therefore, the present invention can be applied to high-frequency signals, and can also be applied to wireless communication.
FIG. 11 shows an embodiment according to the present invention. As shown in FIG. 11, for example, after the encoding shown in FIG. 4 is performed on the transmission side, each of the pulse position modulation signals duplicated by the pulse position modulators 1 to N is added to the high-frequency phase shifter P from the oscillator OSC. _{1 to} P _{N / 2}
Are multiplied by the multipliers M _{1 to} M _{N / 2} , and further added and multiplexed, while π / 2
Multiplied by the frequency of the oscillator OSC phase-shifted multiplier M _i, the received signal M _q, divided into the pulse position modulated signal through phase discriminator circuit, after demodulation, decoding the previous coding, the reproduced data symbols obtain.

According to a tenth aspect of the present invention, in the interference elimination system between multiple signals according to the third aspect of the present invention, a data set of a conversion table (see FIG. 5) used for encoding and decoding is changed for each terminal and transmitted. By switching the data set that matches the conversion table of the recipient for each partner,
It enables normal communication only with specific recipients. Unless the other party's conversion table is known, normal communication cannot be performed, so that an encryption function can be provided.

[0029]

According to the first to sixth aspects of the present invention, on the transmitting side, each combination of data values of a plurality of original data symbols (multi-valued) multiplexed with each other is determined in accordance with a predetermined coding rule. A set of original data symbols to be multiplexed is converted into a set of coded data symbols by means for converting into a combination of coded data symbol values having different data values corresponding one-to-one, and a multiplexed position modulation signal is generated by the data. Since the receiving side performs the inverse transform on the receiving side, pulses do not overlap with each coded data symbol in the multiplexed position modulation signal, so that it is difficult to perform simple multiplexing of the conventional position modulation signal. Error-free data transmission is possible in a multiplexed position modulation scheme.

According to the seventh and eighth aspects of the present invention, 2
When two multi-level data symbols are transmitted in the communication system using the multiplexed position modulation scheme, when the position modulation pulses for the two data symbols overlap with each other, the output of the position modulation signal for one data symbol is set to zero. Since the original data symbols are reproduced by adding the interpolation function on the receiving side to prevent the disappearance of the pulse, the conventional technique is used while avoiding the pulse overlap for each code data symbol in the multiplexed position modulation signal. Error-free data transmission, which has been difficult with only simple multiplexing of position modulation signals, is now possible with the multiplex position modulation method.

According to the first and seventh aspects of the present invention, the basic modulation method can be applied particularly to the case of pulse position modulation.

According to the second and eighth aspects of the present invention, the basic modulation method can be applied particularly to the case of spread spectrum pulse position modulation.

According to the invention of claim 3, claim 1 or 2
Since the conversion table of the encoding and decoding by the memory is used as a method of realizing the conversion means in the invention of the present invention, it is possible to realize the same circuit by simply changing the data in the memory for any conversion pattern Yes, it is versatile.

According to the fourth to sixth aspects of the present invention, in the communication system based on the interference cancellation method between multiple signals according to the first to third aspects of the present invention, a fixed coding and decoding rule used when the multiplicity is two. Because at least one of the original data symbols is used as it is for position modulation, and the remaining original data symbols can be converted to coded data symbols by a simple operation, Is easy.

According to the ninth aspect of the present invention, as the multiplexing method of the position-modulated pulse signal in the multiple signal interference elimination system of the first to eighth aspects, each position-modulated pulse signal or each position-modulated pseudo-noise is transmitted on the transmission side. The signal is multiplied by a carrier having the same frequency and a different phase, and the signals are added. On the receiving side, a method is used in which discrimination is performed by the carrier phase for each pulse of the multiplexed position modulation pulse signal. The inventions 1 to 8 can be applied, and the invention can be used wirelessly. Further, since a plurality of carriers having different phases or amplitudes are prepared, and signals position-modulated with different data symbols can be transmitted to each of them in parallel, higher-speed data transmission becomes possible.

According to the tenth aspect of the present invention, in the communication system using the multiple signal interference canceling method according to the third aspect of the present invention, the data set of the conversion table used for encoding and decoding is changed for each terminal. It is also possible to provide an encryption function that allows normal communication only with a specific recipient without adding additional hardware.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an example of duplication of a position modulation pulse signal, in which (A) is a conventional example, and (B) is one embodiment of the present invention.
Here is an example.

FIG. 2 shows an embodiment of a communication system according to the multiplex position modulation pulse signal interference cancellation system of the present invention.

FIG. 3 shows an embodiment of a communication system according to the multiplex position modulation spread spectrum pulse signal interference cancellation method of the present invention.

4 shows an example of means for converting (FIG. 4 (A)) and inversely converting (FIG. 4 (B)) into sets of data symbols having different values from each other in FIG. 2 or FIG.

FIG. 5 is a diagram illustrating tables included in memories 1 and 2 illustrated in FIG. 4 and operations thereof.

6 shows another example of means for converting (in FIG. 6 (A)) and inverting (in FIG. 6 (B)) into sets of data symbols having different values from each other in FIG. 2 or FIG.

FIG. 7 shows still another example of means for converting (FIG. 7 (A)) and inversely converting (FIG. 7 (B)) into sets of data symbols of different values shown in FIG. 2 or FIG.

8 shows still another example of means for converting (FIG. 8 (A)) and inversely converting (FIG. 8 (B)) into sets of data symbols having different values in FIG. 2 or FIG.

FIG. 9 shows another embodiment of a communication system according to the dual position modulation pulse signal interference cancellation system of the present invention.

FIG. 10 shows another embodiment of the communication system according to the multiplex position modulation spread spectrum pulse signal interference cancellation method of the present invention.

FIG. 11 shows another embodiment for making a communication system based on the multiplex position modulation pulse signal interference cancellation system of the present invention compatible with radio.

[Explanation of symbols]

_{M 1, M 2 ~M N /} 2, M i, M q ... multiplier, OSC ... _{oscillator, P 1, P 2 ~P N} / 2 ... phase shifter.

Claims (10)

[Claims] 1. A pulse signal is temporally position-modulated according to a data value of a multivalued original data symbol, and interference between the multiplexed signals is suppressed when a plurality of obtained position-modulated pulse signals are multiplexed. A communication system for transmitting and receiving a multiplexed position-modulated pulse signal multiplexed and generated according to a multiplexing method to be removed as a transmission signal, wherein the position-modulated pulse signals to be multiplexed each other on a transmitting side so as not to overlap in time. Each combination of a plurality of original data symbol values to be multiplexed is converted into a combination of encoded data symbol values having different data values corresponding to each other in a one-to-one correspondence according to a predetermined encoding rule, and each encoded data after conversion is converted. The position modulation and multiplexing are performed according to the symbol values, and each position modulation pulse signal separated from the multiplexed position modulation pulse signal received at the receiving side is exchanged with each other. Reproducing a combination of the plurality of encoded data symbol values having different data values, and reconstructing the reproduced combination of the encoded data symbol values in accordance with a decoding rule performing an operation reverse to the encoding rule. A communication system using a multiplex position modulation signal interference cancellation method characterized by decoding a combination of a plurality of original data symbol values and reproducing an original multi-valued original data symbol. 2. A pseudo-noise signal having a predetermined time length is temporally modulated according to a data value of an original data symbol having a multi-level, and a plurality of obtained position-modulated pseudo-noise signals are multiplexed when multiplexing. A spread spectrum communication system for transmitting and receiving a multiplexed position modulation pseudo-noise signal generated and multiplexed according to a multiplexing method for removing interference between the transmission and reception,
Each combination of a plurality of original data symbol values multiplexed with each other on the transmitting side so that the correlation pulses after despreading of the position-modulated pseudo-noise signal to be multiplexed do not overlap with each other in accordance with a predetermined coding rule. Conversion into a combination of coded data symbol values having different data values corresponding to one-to-one, performing the position modulation and multiplexing with each coded data symbol value after conversion, and multiplexing position modulation received at the receiving side. The pseudo noise signal is despread, and a combination of the plurality of coded data symbol values having different data values for each of the separated correlation pulse signals is reproduced, and a combination of the reproduced coded data symbol values is reproduced. The combination of the plurality of original data symbol values is decoded according to a decoding rule that performs an operation reverse to the encoding rule, and an original multi-valued original data is obtained. Communication system according multiplexed position modulated signal interference cancellation scheme, characterized in that play Tashinboru. 3. The communication system according to claim 1, wherein the transmitting side converts the plurality of original data symbol values to be multiplexed into the coded data symbol values. A conversion table that outputs the combination of coded data symbol values that take N different data values in one-to-one correspondence with all the patterns of the combination of M data symbol values to be multiplexed. Preparing, on the receiving side, a multiplexed position modulation signal characterized by preparing a conversion table for performing an inverse conversion of the conversion table for converting the plurality of encoded data symbol values into the original data symbol values. A communication system using an interference cancellation method. 4. In the communication system according to the multiplex position modulation signal interference elimination system according to any one of claims 1 to 3, the fixed coding and decoding rules used when the number of multiplexing is two are set as the fixed coding and decoding rules. On the transmitting side, the value A of the first original data symbol is used as it is as the value of the first encoded data symbol, and the value of the second original data symbol is used as the value of the second encoded data symbol. When the relation between B and the value A of the first original data symbol is B ≧ A, (B + 1) is used, and when B <A, B is used. The value A of the first coded data symbol demodulated as a value is used as it is, and the value B of the second coded data symbol demodulated as a value of the second reproduced data symbol is used as B If '≧ A (B'-1) is used, and when B '<A, B' is used to remove the temporal overlap of the multiplexed position modulation signals. Communications system. 5. The communication system according to claim 1, wherein the fixed coding and decoding rules used when the number of multiplexing is two are set as the fixed coding and decoding rules. On the transmitting side, the value A of the first original data symbol is used as it is as the value of the first encoded data symbol, and the value of the second original data symbol is used as the value of the second encoded data symbol. When the relationship between B and the value of the first original data symbol is B = A, a specific value X other than the value that A can take is used. Otherwise, the same value as B is used. The value of the first demodulated encoded data symbol is used as it is as the value of the reproduced original data symbol of 1, and the value of the second demodulated encoded data symbol is used as the value of the second reproduced original data symbol. value If B 'matches X, the value is A,
In other cases, a communication system using a multiplexed position modulation signal interference cancellation method, wherein B 'is used to remove temporal overlap of the multiplexed position modulation signal. 6. In the communication system according to the multiplex position modulation signal interference elimination method according to any one of claims 1 to 3, the fixed coding and decoding rules used when the number of multiplexing is two are defined as: On the transmitting side, the value A of the first original data symbol is used as it is as the value of the first encoded data symbol, and the value of the second original data symbol is used as the value of the second encoded data symbol. B, and a certain value larger than the maximum possible value of A and B is M, and the remainder obtained by dividing (A + B + 1) by (M + 1) is used. On the receiving side, the value of the first reproduced original data symbol is used. The value A of the first demodulated coded data symbol is used as it is, and the value of the second demodulated coded data symbol is represented by (B '+ A communication system using a multiplexed position modulation signal interference cancellation method, characterized in that temporal overlap of multiplexed pulse position modulation signals is removed by using a value obtained by dividing (MA) by (M + 1). 7. A predetermined pulse signal is temporally modulated according to a data value of an original data symbol having a multilevel, and interference between signals is removed when a plurality of obtained position-modulated pulse signals are duplicated. A communication system for transmitting and receiving a duplex position-modulated pulse signal generated and duplicated according to a system as a transmission signal, wherein a value of a first original data symbol and a value of a second original data symbol are transmitted on the transmission side during duplexing. Only when is equal, either one of the position-modulated pulse signal outputs is set to zero, and only the other position-modulated pulse signal is transmitted as a transmission signal. The missing pulse of the one position modulation pulse signal whose signal output is made zero is reproduced based on the other position modulation pulse signal normally transmitted, and each position modulation pulse after reproduction is reproduced. A communication system using a multiplexed position-modulated signal interference cancellation method, characterized in that the multi-valued original data symbol is reproduced as before with respect to a source signal. 8. A pseudo-noise signal having a predetermined time length is temporally modulated according to a data value of an original data symbol having a multi-level, and a plurality of the obtained position-modulated pseudo-noise signals are interpolated when the signals are duplicated. A spread spectrum communication system for transmitting and receiving a duplex position modulation pseudo-noise signal that is duplicated and generated according to a method of removing interference as a transmission signal, wherein a value of a first original data symbol and a second Only when the values of the two original data symbols are equal, one of them is set to zero, and only the other position-modulated pseudo-noise signal is multiplied by a carrier to be transmitted as a transmission signal. And performs a correlation operation with the same pseudo-noise signal as the transmitting side to reproduce a duplicated position-modulated pulse signal, and converts the duplicated position-modulated pulse signal into each position-modulated pulse signal. After separation, the missing pulse of the one position modulation pulse signal whose signal output is set to zero is reproduced based on the other position modulation pulse signal transmitted normally, and the original position modulation pulse signal is reproduced with respect to each reproduced position modulation pulse signal. A communication system using a multiplexed position modulation inter-signal interference cancellation system, characterized in that the multi-valued original data symbol is reproduced as described above. 9. The communication system according to claim 1, wherein each of the position-modulated pulse signal and the position-modulated pseudo-noise signal is a position-modulated signal. Further multiplexing is performed by multiplying and adding carriers having different phases at the same frequency, and the receiving side separates each position modulation signal for each carrier wave phase, and then converts a data symbol for each position modulation pulse signal. A communication system using a multiplex position modulation signal interference cancellation method, characterized by using multiplexing means for performing reproduction. 10. The communication system according to claim 3, wherein a data set of the conversion table used for encoding on a transmission side and decoding on a reception side is different for each terminal. Is prepared, and the transmitting side selects a data set matched with the conversion table held by the receiving side from the different data sets for each partner, so that communication can be normally performed only with a specific recipient, and an encryption function is provided. A communication system using a multiplexed position modulation signal interference cancellation system, characterized in that: