多基站协作下行系统中异步空时码构造与分析

Design and Analysis of Asynchronous Space-Time Codes over Multiple Base Stations Coordinating Downlink Systems

基于天线集中配置的多输入多输出无线通信系统同步环境下应用的现有正交空时分组码,提出并讨论了应用于多基站协作下行传输的天线分布式配置系统异步环境中基站发射空时编码结构和接收端用户译码实现算法,该码仅要求用户接收端知道信道信息状态即可,通过预设不同的循环前缀大小可对分布在多基站不同地理位置天线具有相对时延差的异步传输信号实现可靠接收。最后,分析了该异步空时码的性能特性,在异步环境下以牺牲部分码速率和编码增益能够获得全空间分集和低复杂度接收译码等性能。

Via transformations of existing orthogonal space-time block codes（STBC） for synchronous multiple input-multiple output（MIMO） wireless communication systems with collocated transmit antennas,the proposed encoding method and decoding algorithm can generate asynchronous orthogonal or diagonal STBC applied in coordinated multiple base stations downlink transmission systems.This method requires channel information state（CSI） only at the receiver.With a cost of code rate and coding gains in form of a circular prefix,the resulting codes allow to provide full space diversity with low-complexity decoding in asynchronous settings.Finally,system performance and the ability to process asynchronous reception of signals element from different geographically separated transmit antennas are analyzed.