A Novel Differential Chaotic Bit-Interleaved Coded Modulation System for Digital Communication System

Abstract

Chaotic modulations demonstrate good communication security, simple transceiver circuits, strong immunity to self-interference, low probability of interception, and high robustness to multipath degradation. But chaotic synchronization is very hard for making an implementation of the communication system. The adaptive filter applications such as echo cancellation and noise cancellation system require adaptive filters with a large filter length. If the standard LMS algorithm is applied to such adaptive filter, this algorithm might take a long time to complete the filtering and coefficients updating process. This length of time might cause problems in these applications because the adaptive filter must work in real time to filter the input signals. In this situation, the LMS algorithm can be used. LMS algorithm is known as a stochastic gradient algorithm. This means that it iterates each tap weight of transversal filter in the direction of the gradient of the squared magnitude of error with respect to the tap weight. The filter is only adapted based on the error at the current. In this proposed system, LMS algorithm is introduced to evaluate the decoding thresholds and to analyze the system performance.