一种高效的串行级联非递归GMSK系统设计  

Design of an Efficient Serially Concatenated Non-Recursive GMSK System

作　　者：刘蒙蒙 余忠洋[1] 路清雅 白宝明[1] LIU Mengmeng;YU Zhongyang;LU Qingya;BAI Baoming(State Key Laboratory of Integrated Services Networks,Xidian University,Xi’an 710071,China)

机构地区：[1]西安电子科技大学综合业务网理论及关键技术国家重点实验室

出　　处：《无线电通信技术》2020年第1期82-87,共6页Radio Communications Technology

基　　金：国家自然科学基金面上项目(61771364)~~

摘　　要：在诸如卫星通信、深空通信和无人机通信等领域中,收发端通常工作在低信噪比、功率和频谱双重受限的条件下。因此,串行级联CPM(包括GMSK调制)方案得到了广泛的关注和应用。针对串行级联CPM中非相干解调算法存在的较大性能损失,提出了一种导频辅助的准相干解调算法。该算法的基本原理是将编码后的序列分成若干组,在每组数据块中分插导频符号后送入调制器,解调时在相邻导频块之间采用状态初始化后的BCJR算法。仿真结果表明:非联合迭代方案下,利用少量导频辅助的准相干解调串行级联CPM系统可以获得接近于相干解调的性能;联合迭代方案下,仅利用2个导频的准相干软输入软输出串行级联CPM系统能够得到将近2 dB的性能增益。此外,设计的串行级联CPM系统还具有一定的抗突发错误能力。Satellite communications,deep space communications and unmanned aerial vehicle(UAV)communications are often subject to low signal to noise ratio(SNR),limited power and spectrum resources.And serially concatenated continuous phase modulation(SCCPM)schemes have been widely used.Considering poor performance of the traditional non-coherent demodulation in the SCCPM scheme,we propose a pilot-aided quasi-coherent demodulation algorithm.Its basic principle is that a coded sequence is divided into groups for transmission;and each group is further divided into code blocks by inserting pilot symbols.Then the BCJR-based detection algorithm is performed over each block with initial and ending trellis-states being determined using the pilot symbols.Simulation results show that,for a non-joint iterative scheme,the SCCPM system can achieve a similar performance with that based on the coherent demodulation;and for a joint iterative scheme,the SCCPM system can obtain 2 dB gains.Besides,the proposed SCCPM system can also correct burst errors.

关 键 词：SCCPM BCJR 导频辅助 迭代译码 

分 类 号：TN911.23[电子电信—通信与信息系统]