Differential chaos shift keying modem and modulation method based on two-path index modulation

Abstract

The invention discloses a differential chaos shift keying modem and a differential chaos shift keying modulation method based on two-path index modulation, and relates to the technical field of chaoscommunication. A two-path index modulation method is used for transmitting a chaos reference signal and a Hilbert reference signal orthorhombic with each other, and an index mapping rule and an inverted index mapping rule are used for modulating and demodulating the signals. According to the modulation method provided by the invention, delay units are used in a transmitting terminal and a receiving terminal; compared with an existing carrier-index differential chaos shift keying (CI-DCSK) technology, under the premise of occupying a same frequency band, the method synchronously transmits two information signals, so that a bit transmission rate of the system is doubled; in addition, the higher spectrum utilization rate and better data security are achieved, and the method provided by the invention is reduced in bit error rate (BER), and shows better bit error rate performance, and the advantages of the BER performance becomes more significant along with the increasing of a bit signal tonoise ratio.

Description

technical field [0001] The invention relates to a differential chaotic shift keying modem and method based on two-way index modulation, belonging to the technical field of chaotic communication. Background technique [0002] Chaotic signals have good auto-correlation and cross-correlation, which meet the requirements of spread-spectrum communication for spread-spectrum codes. At the same time, by using the sensitivity of the chaotic signal to the initial value, a large number of approximately orthogonal chaotic signals can be obtained by changing its initial value. This characteristic is suitable for distinguishing different users in a multi-user environment and meets the requirements of multi-user communication for user identification codes. need. Chaotic digital modulation not only has similar advantages to other spread spectrum modulation schemes, including anti-interference, reducing the impact of fading, etc., but also shows unique advantages in many other aspects, inc...

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Problems solved by technology

[0005] In order to solve the problems of low transmission rate and low spectrum utilization rate of the existing CI-DCSK modulation and demodulation method, the present invention provides a system that can improve the bit transmission rate, spectrum utilization rate and bit error rate performance of the system without reducing data security. Differential chaotic shift keying modem and method based on two-way index modulation

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