水声多径信道中的空时分组扩频编码方案

Proposing STBSC(Space-Time Block Spreading Coding) Scheme for Improving Underwater Acoustic Multipath Communication

基于空时编码的发射分集具有改善水声通信系统性能的潜力,文章提出了一种空时分组扩频编码(STBSC)方案,可以在有多径传播和路径时延的水声信道中获得发射分集。该方案将经空时分组编码后形成的多路信号用不同的正交码扩频,接收信号经相干解扩后进行独立的最大似然译码。文中给出了方案的理论模型,提出了2种构建判决变量的方法,并在有多径时延和传播时延的信道中进行了性能仿真。仿真结果表明,与单发射的直接序列扩频方案相比,采用两发射、单接收的STBSC方案可获得2 dB的分集增益,采用Rake接收还可增加2.5 dB的分集增益。

Aim.Having reviewed what we believe are the shortcomings of Refs.1,2 and 3,we propose STBSC scheme for communicating in underwater acoustic channel(UAC) with multipath spreading and propagation delays.Sections 1 and 2 explain the STBSC scheme.The core of the scheme consists of:(1) the space-time block coding scheme splits transmission data into several groups of transmission signals; (2) each group is then spread with different orthogonal spreading codes;(3) the coherent despreading signals are input to a d...