A joint source and channel coding scheme base on simple protograph structured codes

摘要

A scheme of joint source and channel coding (JSCC) with double Low Density Parity Check (LDPC) structure has been proposed recently, which results in a popular and promising research topic for further improving JSCC design at physical layer. However, it becomes an important problem how to enhance the error performance and reduce the complexity of the whole system. Therefore, we propose a state-of-the-art JSCC scheme, denoted as P-JSCC, based on simple protograph structured codes considering the performance and hardware advantages of such LDPC-like codes. The simulation results with different lengths of source sequence show that the Bit Error Ratio (BER) performance of the proposed scheme is better than that of the previous JSCC scheme base on regular LDPC codes, denoted as traditional [1], in the turbo cliff region. Furthermore, it is found that the performance of the proposed JSCC scheme becomes worse as p1, the probability of binary bit with value one in source sequence, increases. Eventually, we enlarge the degree of check nodes in source code while keep the channel code invariable, and the simulation results illustrate that a significant improvement is achieved on error floor region.