基于直接序列扩频和频域均衡的满多径分集块传输系统

Exploring Full Multipath Diversity Block Transmission System Based on Direct Sequence Spreading and Frequency Domain Equalization

为了获得信道的满多径分集增益,基于直接序列扩频和线性频域均衡,提出了一种单载波块传输系统。发射信号在时域的直接序列扩频,造成了信号在频域的重复和交织。接收端通过最大比合并频域均衡,均衡和解扩同时在频域内完成。理论分析表明,对于多径数目为L的多径信道,系统可以获得分集阶数为L的满多径分集增益。与传统的线性频域均衡系统相比,系统具有更低的误码率和更低的计算复杂度。理论分析的结果通过计算机仿真进行了验证。

If the signal receiver simply relies on linear equalization , itis difficult for the block transmission system to obtain the full multipath diversity gains of the wireless channel .To achieve this , we propose a single carrier block transmission system based on direct sequence spreading and maximum ratio combination frequency domain equaliza -tion.The direct sequence spreading of transmission signals in the time domain results in signal repetition and inter -leaving in the frequency domain .Through maximal ratio combination frequency domain equalization , the despreading and equalization are carried out simultaneously in the frequency domain .The simulation results , given in Figs.2, 3 and 4, and their analysis show preliminarily that：（1） the block transmission system we proposed can obtain full multipath diversity gains （2） it has lower computational complexity and bit error rate than the conven-tional linear frequency domain equalizer .