收稿日期: 2016-07-07
修回日期: 2016-10-17
网络出版日期: 2017-05-30
基金资助
天津市科技兴海项目基金（No.KJXH2011-2）；国家自然科学基金（No.61671324）资助
Performance Analysis of Coded Modulation Signal Based on Software-Defned Radio
Received date: 2016-07-07
Revised date: 2016-10-17
Online published: 2017-05-30
为评估编码调制信号在实际无线信道下的性能，利用通用软件无线电外设（universalsoftware radio peripheral,USRP）对Turbo码、二进制低密度奇偶校验（low density paritycheck,LDPC）码、多进制LDPC码等3种信道编码方案的八进制相移键控调制信号实际性能进行对比分析。为保证译码器获得准确的先验信息，首先基于同步序列实现八进制相移键控系统相位模糊的检测和恢复；然后利用经验特征函数实现信道噪声方差的估计；进而计算出译码器输入符号的先验概率。仿真与测试结果表明，在较短的码长下，采用上述3种编码方式均可以获得优越的系统性能，并且多进制LDPC码的性能优于2进制LDPC码与Turbo码的性能。
邹杰, 陈为刚, 杨晋生 . 基于软件无线电的编码调制信号性能分析[J]. 应用科学学报, 2017 , 35(3) : 275 -287 . DOI: 10.3969/j.issn.0255-8297.2017.03.001
To evaluate the performance of coded and modulated signals in a wireless channel, experiments are performed based on the universal software radio peripheral (USRP). Performances of coding and modulation schemes using 8 phase-shift keying and three channel coding schemes, including turbo codes, binary low density parity check (LDPC) codes and non-binary LDPC codes, are compared and analyzed. To ensure accuracy of the apriori probability, phase ambiguity in the symbol of 8 phase-shift keying is detected and recovered based on frame synchronization sequences. An empirical characteristic function is used to estimate the channel noise variance. Furthermore, a priori probability is calculated from the recovered symbol and the estimated noise variance. Simulation and experimental results show that, with short code length, superior performance can be achieved with the three channel coding schemes, and non-binary LDPC codes performs better than binary LDPC codes and Turbo codes.
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