JPH08293860A - Speech ciphering communication equipment - Google Patents

Abstract

PURPOSE: To simplify the constitution of a radio communication equipment by consisting of error-corrected and decoded information, etc., and varying a generation polynominal expression so as to code a speech signal to be transmitted. CONSTITUTION: An inputted analog speech signal is speech-efficient-coded by an information source coder 1 to obtain a parameter, inputted to an error correction coding device 2 to be error-correction-coded, and data-mixed by an interleave 3. This coding device 2 is controlled and instructed from a controller 15 to timewise vary the generation polynominal expression of error correction coding. Then mixed data is modulated by a modulator 5, amplified by a power amplifier 6 and transmitted to a power receiving side through an antenna switch 7 for switching transmission/reception and an antenna 8. Then a radio signal received by a receiver 9 is decoded to a digital speech signal by a demodulator 10 and mixed data is returned to its former state by a de-interleave 12. Then error correction decoding is executed by a correction decoding device 13 while being timewise controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voice-encryption telephone apparatus which has a confidential communication function by encoding and encrypting a voice signal in a digital communication system or the like.

[0002]

2. Description of the Related Art In order to prevent the contents of communication from being heard on a telephone line, a confidential communication device is generally used. Specifically, a confidential communication device is provided for each telephone terminal and a voice signal is transmitted by the confidential communication device. It was converted into an encrypted signal and encrypted communication was carried out between the confidential devices of the telephone terminals.

For example, in an analog communication system having a conventional confidential communication function, a frequency spectrum array of a voice signal is arranged on the transmitting side based on a predetermined rule, and the obtained encrypted voice signal is passed through a communication line. The encrypted communication system that uses voice scrambling to restore the original audio signal by relocating the received encrypted audio signal to the receiving side based on the same rules as the transmitting side and reconstructing the original audio signal has been put to practical use. ing.

Also in a digital communication system,
Voice encryption is in progress, and FIG. 2 is a block diagram showing the configuration of a conventional digital wireless communication device. On the sending side,
The analog voice signal input by the information source encoder 1 is converted into a digital voice signal. The digital audio signal is
Channel coding for error protection is performed by the error correction encoder 2 and the interleave 3. The channel-encoded digital audio signal is converted into an encryption code by the encryption encoder 4. The cipher code output from the cipher encoder 4 is modulated by the modulator 5. The modulated signal is power-amplified by the power amplifier 6 and transmitted by the antenna 8 to the receiving-side wireless communication device. The antenna switch 7 is for switching between transmission and reception.

On the receiving side of the digital communication system, the reception signal received via the antenna 8 and the antenna switch 7 is received by the receiver 9. The received signal is demodulator 1
It is demodulated by 0 into an encrypted code. The demodulated signal (encryption code) from the demodulator 10 is decoded by the encryption / decryption unit 11 into a digital audio signal. The data interlaced by the deinterleave 12 is returned to the original state, and the data output from the deinterleave 12 is input to the error correction decoder 13 for error correction and detection, information interpolation, and the like. The information source decoder 14 converts the digital audio signal into an analog audio signal and outputs it. The wireless communication device is used as a command station, a relay station, and a terminal station (fixed station, mobile station, mobile station) of a wireless communication system.

[0006]

However, in both the above techniques, the line scale becomes large when the voice scramble is applied to the analog voice signal, and in the case of digital, the configuration is adopted in which the feature of the voice signal is used for encoding. Therefore, the scrambled voice cannot be encoded or decoded. In addition, when the encoded data is encrypted, there is a problem that the configuration of the wireless communication device becomes complicated because an encryption device such as an encryption encoder and an encryption / decryption device is required.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide an encrypted communication device having a simple device configuration.

In order to achieve the above object, the present invention provides a voice encryption communication device for encrypting and transmitting a voice signal, an information source encoding means for encoding the voice signal, and a communication for error protection. Error correction coding means for path coding,
Interleaving means for distributing errors, transmitting means for transmitting interleaved information, generator polynomial varying means for temporally changing the generator polynomial of an error correction code, and receiving means for receiving information through a communication channel A deinterleaving means for channel decoding for decoding the received information received, an error correction decoding means for performing error correction / detection, and an information source decoding means for error-correction decoded information. The audio signal is encrypted and transmitted by changing the generator polynomial.

[0009]

With the above-described structure, the transmission side does not perform encryption after channel coding but performs source coding for high efficiency coding of the analog voice signal, and the source coding is performed. Channel coding is performed to protect voice signals from errors. Error correction and interleaving are performed in channel coding, the generator polynomial of error correction coding is temporally controlled, and the generator polynomial is changed. The interleaved information is
It is modulated and transmitted. On the receiving side, the received information is demodulated, and the demodulated information is a mixture of data,
Undo by deinterleaving. The deinterleaved information is error correction decoded. Information source decoding is performed on the error-corrected decoded information.

Since the generator polynomial of the error correction coding changes with time, the decoding method cannot be known by a decoder that is not communicating. The voice signal decoded by the external decoder becomes a voice completely different from the transmitted signal and can be encrypted. That is, it becomes impossible to decipher the communication content by intercepting the telephone line, and the confidentiality of the communication content can be maintained.

An encryption function is provided by providing means for temporally controlling the generator polynomial for error correction coding,
Eliminate the encryption device after channel coding. Since there is no encryption device, a memory for storing information for encryption is not needed, and the wireless communication device is simplified.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In the figures, the same parts are designated by the same reference numerals.

FIG. 1 is a block diagram showing a circuit configuration of a digital communication device showing an embodiment of the present invention.

On the transmission side of this apparatus, the input analog voice signal is subjected to high-efficiency voice encoding by the information source encoder 1 to obtain parameters. The high-efficiency coded data is input to the error correction coder 2, is error-correction coded, and then is interleaved by the interleave 3. The error correction encoder 2 is controlled and instructed by the control unit 15 so that the generator polynomial of the error correction encoding changes with time. The mixed data is modulated by the modulator 5, power-amplified by the power amplifier 6, and transmitted through the antenna switch 7 and the antenna 8 for switching between transmission and reception.

The radio signal that has passed through the transmission path is input to the receiver 9 via the antenna 8 and the antenna switch 7 on the receiving side. The radio signal received by the receiver 9 is decoded by the demodulator 10 into a mixed digital audio signal.
The decoded digital audio signal is deinterleaved 12
The data intermixed by is restored. The error correction decoder 13 performs error correction decoding. At this time, the error correction decoding is temporally controlled by the control unit 15. The error-correction-decoded data becomes a digital audio signal. The decoded digital voice signal is efficiently decoded by the information source decoder 14 and converted into an analog voice signal.

[0016]

As described above, according to the configuration and method of the present invention, since the generator polynomial of the error correction code is changed with time, the decoder which is not communicating can decode the decoding. However, the voice signal decoded by the external decoder is completely different from the transmitted signal and can be encrypted. That is, it becomes impossible to decipher the communication content by intercepting the telephone line, and the confidentiality of the communication content can be maintained.

By providing means for temporally controlling the generator polynomial of the error correction code, it is possible to provide an encryption function and eliminate the encryption device after channel coding. Since there is no encryption device, a memory for storing information for encryption is not needed, and the configuration of the wireless communication device is simplified.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a voice encryption communication device of the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional voice encryption communication device.

[Explanation of symbols]

 1 Information Source Encoder 2 Error Correction Encoder 3 Interleave 4 Cryptographic Encoder 5 Modulator 6 Power Amplifier 7 Antenna Switch 8 Antenna 9 Receiver 10 Demodulator 11 Crypt Decoder 12 Deinterleave 13 Error Correction Decoder 14 Information Source Decoder 15 Control unit

Claims (1)

[Claims] 1. A voice encryption communication device for encrypting and transmitting a voice signal, comprising: an information source coding means for coding the voice signal; and an error correction coding means for channel coding for error protection. , Interleaving means for distributing errors, transmitting means for transmitting interleaved information, generator polynomial varying means for temporally changing the generator polynomial of an error correction code, and receiving for receiving information through a communication channel Means, deinterleaving means for channel decoding for decoding received information received, error correction decoding means for performing error correction / detection, and information source decoding means for error correction decoded information A voice encryption communication device, characterized in that the voice signal is encrypted and transmitted by varying the generator polynomial.