基于Rayleigh衰落信道下LDPC编码的星座成形  

Constellation Shaping Based on LDPC Coding in Rayleigh Fading Channel

作　　者：林峰懋 陈慧彬 陈平平[1] LIN Fengmao;CHEN Huibin;CHEN Pingping(College of Physics and Information Engineering,Fuzhou University,Fuzhou 350108,China)

机构地区：[1]福州大学物理与信息工程学院,福建福州350108

出　　处：《无线电工程》2022年第1期88-92,共5页Radio Engineering

基　　金：国家自然科学基金面上项目(61871132)。

摘　　要：针对消息在信道传输过程中的成形损耗问题,提出了一种在Rayleigh衰落信道下基于低密度奇偶校验(Low-Density Parity-Check, LDPC)编码的星座成形系统。该方法基于脉幅调制(Pulse Amplitude Modulation, PAM)下的星座图,通过在发送端加入一个成形编码器(作用是提高输出比特为0的概率),使得星座图中低能量的符号比高能量的符号更容易被选中,从而提高成形增益。并且在解调器和译码器之间进行迭代译码,进一步提高了系统的性能。理论分析和仿真结果表明,在独立Rayleigh衰落信道下,与不采用星座成形的系统相比,该方案大大提高了系统的误差性能和成形增益。To address the problem of message shaping loss in the process of channel transmission, a constellation shaping system based on Low-Density Parity-Check(LDPC) coding in Rayleigh fading channel is proposed.Based on the constellation under Pulse Amplitude Modulation(PAM),a shaping encoder is added to the transmitter(the purpose is to increase the probability of 0 output bit),so the low-energy symbols in the constellation are easier to be selected than the high-energy ones, thereby increasing the shaping gain.Iterative decoding between the demodulator and the decoder further improves the system performance.The simulation results show that as compared with the system without shaping, the proposed scheme greatly improves the error performance and shaping gain in independent Rayleigh fading channels.

关 键 词：RAYLEIGH衰落信道 星座成形 脉幅调制 成形增益 

分 类 号：TN92[电子电信—通信与信息系统]