JP4047302B2 - Multi-frame communication system - Google Patents

Description

  The present invention is used in a communication device that transmits and receives signals using multiframes. In particular, it relates to a communication confidential processing technique.

  In a conventional method for preventing communication interception by others, there is a method in which communication information is encrypted and transmitted, and on the receiving side, the communication information is decrypted and the original communication information is acquired (see, for example, Patent Document 1). ).

  Alternatively, there is a method in which the transmission signal is spread over a wide band based on a certain pattern, and the transmission signal that has been spread spectrum based on the pattern is collected on the receiving side to acquire the original transmission signal.

JP 2000-206877 A

  Conventional methods for preventing communication interception by others are mainly realized by using a concealment device that performs signal concealment processing separately from the communication device, which is expensive. Further, in the conventional technology, the communication information encoding and decoding patterns for concealing communication information are always constant, and therefore there is a problem that decryption is always possible if an encryption key is available. In communications that require high performance, a more advanced concealment method is required.

  The present invention has been made against this background, and the present invention changes the signal permutation of a multi-frame signal at regular time intervals in a communication device or a modem that communicates using a multi-frame signal. Accordingly, it is an object to easily realize a highly confidential processing with high confidentiality.

  Further, it is an object of the means to be realized in the apparatus by internal processing of the communication apparatus and the modulation / demodulation apparatus, so that it can be realized at a lower cost than a case where a secret apparatus is separately prepared.

  It is another object of the present invention to significantly reduce the risk of intercepting communications by others by combining multi-frame signals and multi-carrier communications.

  In the present invention, in a transmission device that uses a multiframe signal, the permutation of signals in the case of multiframe conversion is changed according to an algorithm that randomly changes every predetermined time, and the multiframe signal is transmitted in the reception device. By performing demultiframe reception according to a signal permutation changed at regular intervals by an algorithm common to the algorithm of the transmission apparatus, it is possible to easily realize a highly confidential processing.

  Further, in the algorithm, communication with higher secrecy can be realized by using a random pattern generated by a common key shared by the transmission device and the reception device.

  In addition, a bit error due to a missing bit in a change in signal permutation during communication by adding a bit string indicating the timing of the signal permutation change of the transmitting device and the receiving device and changing the signal permutation according to the timing by the bit sequence Can be prevented.

  Further, in a multicarrier transmission apparatus and multicarrier reception apparatus that transmit and receive multiframe signals by multicarrier, the number of carriers, bandwidth, and frame length of the multicarrier are changed in conjunction with the algorithm for determining the signal permutation. As a result, it is possible to remarkably reduce the risk of being intercepted by another person.

  Further, in a multi-carrier modulation apparatus having means for modulating multi-frame signals almost simultaneously by time division and means for combining and outputting them by different frequency bands, the stage of serial signals prior to multi-frame conversion In a multicarrier demodulator that performs bit interleaving with a permutation that changes at regular intervals according to a specific algorithm and communicates in opposition to the multicarrier modulator, each received multicarrier signal is demultiplexed to obtain a multiframe signal. The plurality of multi-frame signals are demodulated almost simultaneously by time division, the demodulated multi-frame signals are converted into parallel signals and converted into parallel signals, and the parallel signals are converted into serial signals. The multi-carrier modulation device; By performing bit deinterleaving by permutation is changed every predetermined time by like algorithm, it is possible to easily realize a high degree a highly confidential security processing.

That is, the first aspect of the present invention is a transmission device that transmits a multi-frame after converting a serial signal into a parallel signal, and an algorithm that randomly changes the permutation of the signals at the time of multi-frame conversion the a, Ru transmitting apparatus der characterized by having means for transmitting the multi-frame signal by a signal permutation is changed for each predetermined time in accordance with the algorithm.

Furthermore, the transmission apparatus of the present invention comprises means for transmitting the multiframe signal by multicarrier, and the means for transmitting is coupled with the algorithm for determining the signal permutation and the number of carriers of the multicarrier and the bandwidth. and Ru can be provided with means for transmitting by changing the frame length.

A second aspect of the present invention is a receiving apparatus that communicates with the transmitting apparatus according to the present invention, wherein the permutation of signals at the time of multiframe conversion is randomly changed at regular intervals. algorithm with apparatus and have a common algorithm, Ru receiving apparatus der, wherein a multi-frame coded signal having means for receiving according to modified signal permutation at regular intervals by the algorithm.

Furthermore, the receiving apparatus of the present invention comprises means for receiving the multi-frame signal by multi-carrier, and the means for receiving is coupled with the algorithm for determining the signal permutation and the number of carriers and bandwidth of the multi-carrier. and frame length Ru can comprise means for receiving a multicarrier signal that has been changed.

A third aspect of the present invention is a multi-frame communication system including the transmission device of the present invention and the reception device of the present invention, wherein the permutation of signals at the time of the multi-frame conversion is set at regular intervals. when executing an algorithm that randomly changed, characterized in that the transmitting device and the receiving device comprises means for using the random pattern generated by the common key having in common.

Alternatively, the multiframe communication system according to the present invention includes means for adding a bit string indicating the timing of the change in the transmitting apparatus and the receiving apparatus when the signal permutation is changed at regular intervals by the algorithm, and the bit string by you, characterized in that a means for changing the signal permutation timed.

  An effect of the present invention is to realize a communication that is not intercepted by others by easily realizing a highly confidential processing with a high degree of secrecy in a communication device and a modem that communicate using multiframe signals. In addition, since it can be realized by internal processing of the communication device and the modem, this can be realized at low cost. Furthermore, the risk of eavesdropping on communication by others can be significantly reduced by the combination of multiframe signals and multicarrier communication.

(First Example)
An example of signal processing of the transmission apparatus according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram showing a main part block configuration and signal form of the transmission apparatus of the first embodiment. In FIG. 1, the serial signal input to the transmission device is converted from a serial signal to a parallel signal by the serial / parallel conversion unit 1, and then converted into a multiframe by the multiframe conversion unit 2. At this time, signal permutation, the algorithm execution circuit 3 is determined randomly every t seconds according to a specific algorithm, the multi-frame signal generated based on the determined permutation that are sent.

(Second embodiment)
An example of signal processing of the receiving apparatus according to the second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a diagram showing a main part block configuration and signal form of the receiving apparatus of the second embodiment. The signal received in FIG. 2 is demultiplexed by the demultiframe unit 12 according to the signal permutation randomly determined every t seconds by the algorithm execution circuit 13 according to the same algorithm as that of the transmission apparatus of the first embodiment. are processed framed, Ru is converted from a parallel signal to a serial signal by the parallel / serial converter 11.

(Third embodiment)
A random pattern generation method by the algorithm execution circuit of the third embodiment of the present invention will be described with reference to FIG. FIG. 3 is a diagram showing a main part block configuration including both the transmitting apparatus and the receiving apparatus and the flow of processing. In FIG. 3, the random pattern generated by the algorithm execution circuit 3 that determines the signal permutation of the multiframe signal of the transmission device 10 and the random pattern generated by the algorithm execution circuit 13 of the reception device 20 are both common and common. Ru is determined for each t seconds by the key.

(Fourth embodiment)
An example of signal processing of the transmitting apparatus and the receiving apparatus according to the fourth embodiment of the present invention will be described with reference to FIG. FIG. 4 is a diagram showing signal forms of the multi-frame unit and the de-multi-frame unit of the fourth embodiment. In FIG. 4, in the transmission device, the parallel-converted signal is converted into multiframes by the multiframe conversion unit 2 and the signal permutation is randomly changed every t seconds by a specific algorithm. A unique bit pattern consisting of a specific number of bits is inserted as a synchronization bit T for each number of bits transmitted during t seconds. This can be used as a signal indicating the timing of changing the signal permutation.

The demultiframe unit 12 of the receiving apparatus detects the synchronization bit T, which is a unique pattern every t seconds, measures the timing at which the signal permutation is changed, and synchronizes with this to signal the same as the transmitting apparatus by performing de-framed by permutation, Ru can be prevented bit missing and the bit error due to the timing shift of the signal permutation changes.

(Fifth embodiment)
An example of signal processing of the transmitting apparatus and the receiving apparatus according to the fifth embodiment of the present invention will be described with reference to FIG. FIG. 5 is a diagram illustrating the relationship between multiframe signals and multicarrier signals. In FIG. 5, a transmission device and a reception device communicate with each other using a multicarrier signal using a multiframe signal. In the state before the change, each of the transmission device and the reception device uses multiframes F1 to F8, and the frame length of the multiframe is 10 bits including a synchronization T bit as one frame. Multi-carrier communication is performed as a transmission carrier.

Multi-frame signal in the transmitter and the receiver are changed each frame length to any multiple of 10 bits, the number of carriers and the bandwidth of the multi-carrier signal is also Ru are optionally modified accordingly.

  In FIG. 5, in the changed state, five multi-frame signals from F1 to F5 have a frame length of F1 is 20 bits, F2 is 10 bits, F3 is 10 bits, F4 is 30 bits, and F5 is 10 bits. Correspondingly, the number of carriers of the multi-carrier signal is 5 carriers, the bandwidth is F1 is double, F2 is 1 time, F3 is 1 time, F4 is 3 times, and F5 is 1 time.

  By combining such a multi-frame signal and multi-carrier communication, it is possible to remarkably reduce the risk of communication being intercepted by others.

(Sixth embodiment)
An example of signal processing of the multicarrier modulation apparatus according to the sixth embodiment of the present invention will be described with reference to FIG. FIG. 6 is a diagram showing the main block configuration and signal form of the multicarrier modulation apparatus of the sixth embodiment. In FIG. 6, the transmission signal is bit-interleaved in the serial signal processing unit 30 according to a permutation changed every t seconds by a specific algorithm by the algorithm execution circuit 35. The bit interleaved transmission signal is converted from a serial signal to a parallel signal by the serial / parallel conversion unit 31 and then converted into multiframes by the multiframe processing unit 32, and each signal is converted into an arbitrary signal by the time division modulation circuit 33. modulated by time division rate, the signal modulated in the multi-frame filter bank 34, Ru is transmitted as synthesized in any band of different frequencies multicarrier signal.

(Seventh embodiment)
An example of signal processing of the multicarrier demodulator according to the seventh embodiment of the present invention will be described with reference to FIG. FIG. 7 is a diagram showing the main part block configuration and signal form of the multicarrier demodulator of the seventh embodiment. In FIG. 7, the received signal is received as a multicarrier signal of an arbitrary band having a different frequency, demultiplexed by the multiframe filter bank 44, demodulated by the time division demodulation circuit 43, and demultiplexed by the demultiframe processing unit 42. After being converted into a multi-frame, the parallel / serial conversion unit 41 converts the serial signal into a serial signal. The serial signal processing unit 40 uses the algorithm execution circuit 45 in the serial signal processing unit 40 to specify a specific algorithm similar to that of the multicarrier modulation apparatus of FIG. Ru is a debit interleaved in accordance with the permutation that is changed for every t seconds by.

(Eighth Example)
A random pattern generation method by the algorithm execution circuit of the eighth embodiment of the present invention will be described with reference to FIG. FIG. 8 is a diagram showing a main part block configuration including both the transmitting apparatus and the receiving apparatus and the flow of processing. In FIG. 8, both the random pattern generated by the algorithm execution circuit 35 that determines the signal permutation of bit interleaving in the multicarrier modulation apparatus 50 and the random pattern generated by the algorithm execution circuit 45 of the multicarrier demodulation apparatus 60 have both. by the common of the common key Ru is determined for each t seconds.

  The present invention can remarkably reduce the risk of intercepting communications by others as compared with the prior art, and can realize this at a low cost. It can contribute to the development of equipment.

The figure which shows the principal part block structure and signal form of the transmitter of a 1st Example. The figure which shows the principal part block structure of the receiver of 2nd Example, and the form of a signal. The figure which shows the principal part block structure including both a transmitter and a receiver, and the flow of a process. The figure which shows the signal format of the multi-frame part of a 4th Example, and a de-multi-frame part. The figure which shows the relationship between a multi-frame signal and a multicarrier signal. The figure which shows the principal part block structure and signal form of the multicarrier modulation apparatus of 6th Example. The figure which shows the principal part block structure and signal form of the multicarrier demodulation apparatus of 7th Example. The figure which shows the principal part block structure including both a transmitter and a receiver, and the flow of a process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 31 Serial / parallel conversion part 2 Multi frame conversion part 3, 13, 35, 45 Algorithm execution circuit 4 Timing bit addition part 10 Transmission apparatus 11, 41 Parallel / serial conversion part 12 Demulti frame conversion part 20 Reception apparatus 30, 40 serial signal processing unit 32 multiframe processing unit 33 time division modulation circuit 34, 44 multirate filter bank 42 demultiframe processing unit 43 time division demodulation circuit 50 multicarrier modulation device 60 multicarrier demodulation device

Claims (4)

A transmission device that transmits a multi-frame after converting a serial signal into a parallel signal,
It has an algorithm that randomly changes the permutation of signals when converting into multiframes at regular intervals,
Have a means for transmitting the multi-frame signal by a signal permutation is changed for each predetermined time in accordance with the algorithm,
The means for transmitting the multiframe signal comprises means for transmitting the multiframe signal by a multicarrier,
The transmitting means comprises means for transmitting by changing the number of carriers, bandwidth and frame length of a multicarrier in conjunction with the algorithm for determining a signal permutation . A receiving device that communicates with the transmitting device according to claim 1,
A common algorithm to the algorithm of the transmission device according to claim 1, wherein the permutation of signals in multi-frame conversion is randomly changed at regular intervals.
The multi-frame coded signal have a means for receiving in accordance with modified signal permutation at regular intervals by the algorithm,
Means for receiving the multi-frame signal by multi-carrier,
The receiving means comprises means for receiving a multicarrier signal in which the number of carriers, bandwidth and frame length of the multicarrier are changed in conjunction with the algorithm for determining the signal permutation. apparatus. 1 SL and placing of the transmission device according to claim, a multi-frame communication system comprising a receiving apparatus according to claim 2 Symbol placement,
Means for using a random pattern generated by a common key shared by the transmission device and the reception device when executing an algorithm for randomly changing the permutation of signals at the time of multiframe conversion at regular time intervals A multi-frame communication system characterized by that. 1 SL and placing of the transmission device according to claim, a multi-frame communication system comprising a receiving apparatus according to claim 2 Symbol placement,
Means for adding a bit string indicating the timing of the change in the transmission device and the reception device when changing the signal permutation at regular intervals by the algorithm;
Means for changing the signal permutation in accordance with the timing of the bit sequence.

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