Hadamard Matrix Based Correlation Delay Keying Chaotic Communication Method

Abstract

The invention discloses a Hadamard matrix-based related delay keying chaos communication method to overcome the defect of a relatively high bite error rate caused by existence of mutual interference components between adjacent bits in a related delay keying chaos communication method. A chaotic signal source in a system transmitter is used as a reference signal after frequency spread performed by a Hadamard matrix, to-be-transmitted data is subjected to cycle LDPC (low density parity check code) encoding, the transmitted signal is a sum signal of reference signals and signals with self delay and subjected to data modulation, and then the sum signal is multiplied by a high-frequency sine wave to perform frequency division multiple access modulation. A received signal is multiplied by the high-frequency sine wave and signals of a user are extracted by a wave filter at first, then differential demodulation is performed, and finally, decoding is performed by virtue of a cycle LDPC channel. An analysis shows that the method can well eliminate the mutual interference components between the adjacent bits, can achieve multiple access communication easily, and greatly reduces the bit error rate.

Description

technical field

[0001] The invention belongs to the field of communication, in particular to a Hadamard matrix-based correlation delay keying chaotic communication method. Background technique

[0002] The noise-like characteristics of chaotic carrier signals, sensitivity to initial values ​​and wide spectrum characteristics make chaotic communication develop rapidly in the field of communication with security and confidentiality requirements, and become one of the important research contents in the field of information security. It has good application value in civilian and military use. The chaotic keying communication method has the advantages of simple circuit structure, easy implementation, low interception rate and strong confidentiality. kind. The signal sent by the sender of the correlation delay keying chaotic communication system is the sum signal of the reference chaotic signal and its own delayed and data-modulated signal, that is, the sent signal includes both...

Examples

Embodiment Construction

[0019] The schematic diagram of the transmitter and receiver of the correlated delay keying chaotic communication (CDSK) method is shown in figure 1 and figure 2 As shown, the signal sent by the sender is the sum signal of the reference chaotic signal and its own delayed and data-modulated signal, is the amount of delay in time. It can be seen that the transmitted signal includes both the reference chaotic signal and the signal after data modulation, and the interference between the front and rear bits is serious. The receiver adopts the form of differential demodulation, and uses the low cross-correlation of chaotic signals to realize data judgment. However, with the decrease of the spreading factor of the chaotic sequence, the orthogonality of the chaotic signal gradually deteriorates. When the signal-to-noise ratio is low, the mutual interference components between the front and rear bits become the primary factor affecting the bit error rate of the CDSK system. The s...

technical field

[0001] The invention belongs to the field of communication, in particular to a Hadamard matrix-based correlation delay keying chaotic communication method. Background technique

[0002] The noise-like characteristics of chaotic carrier signals, sensitivity to initial values ​​and wide spectrum characteristics make chaotic communication develop rapidly in the field of communication with security and confidentiality requirements, and become one of the important research contents in the field of information security. It has good application value in civilian and military use. The chaotic keying communication method has the advantages of simple circuit structure, easy implementation, low interception rate and strong confidentiality. kind. The signal sent by the sender of the correlation delay keying chaotic communication system is the sum signal of the reference chaotic signal and its own delayed and data-modulated signal, that is, the sent signal includes both...

Examples

Embodiment Construction

[0019] The schematic diagram of the transmitter and receiver of the correlated delay keying chaotic communication (CDSK) method is shown in figure 1 and figure 2 As shown, the signal sent by the sender is the sum signal of the reference chaotic signal and its own delayed and data-modulated signal, is the amount of delay in time. It can be seen that the transmitted signal includes both the reference chaotic signal and the signal after data modulation, and the interference between the front and rear bits is serious. The receiver adopts the form of differential demodulation, and uses the low cross-correlation of chaotic signals to realize data judgment. However, with the decrease of the spreading factor of the chaotic sequence, the orthogonality of the chaotic signal gradually deteriorates. When the signal-to-noise ratio is low, the mutual interference components between the front and rear bits become the primary factor affecting the bit error rate of the CDSK system. The s...

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