摘要
GMSK具有窄带宽和恒包络的良好特性,但现行的GMSK调制暴露了码间串扰和编码增益等问题。对多进制GMSK调制展开了研究,与现行的GMSK调制性能做了比较。首先介绍了多进制GMSK调制体制的基本原理,以4GMSK为例做了相关研究,讨论了调制指数和信号相位终值,然后根据恢复出的附加相位轨迹提出了抽样法和积分法两种解调方案。最后通过Matlab仿真来分析其误码率和频谱,从而得到其传输性能。多进制GMSK的进一步研究可在更高阶调制数和提高频带利用率上展开。
GMSK has good characteristics of narrow band and constant envelope. However the current GMSK modulation system exposes the problems of inter-symbol interference and coding gain. Multi-ary GMSK modulation is investigated and its performance is compared with the current GMSK modulation. The basic principles of M-ary GMSK modulation system is introduced. 4GMSK modulation is considered as an example and its modulation index and signal phase terminal value is discussed. Based on the additional phase trajectory the sampling method and integral method are proposed to demodulate the signal. The transmission performance of modulation system is obtained by analyzing its bit error rate and frequency spectrum through Matlab simulation. Further research of M-ary GMSK can be focused on higher order modulation and improvement of bandwidth efficiency.
出处
《指挥控制与仿真》
2015年第5期133-138,共6页
Command Control & Simulation
