循环前缀不足空时编码协作OFDM系统的判决反馈均衡

在空时编码协作通信系统中,正交频分复用（OFDM）技术用于对抗各个中继节点到目标节点的时延干扰.中继到目标节点的信道可以被看作多径信道,当循环前缀长度小于时延长度时,符号间干扰无法完全消除.为了解决这个问题,在循环前缀不足的空时编码协作OFDM系统中引入判决反馈均衡器,设计了基于迫零准则和最小均方误差准则的两种判决反馈均衡器.仿真结果表明,这两种均衡器都能很好地改善系统性能,基于最小均方误差准则的判决反馈均衡器（MMSE-DFE）性能更佳.

Decision Feedback Equalization for ALAMOUTI-Coded Cooperative OFDM Systems with Insufficient Cyclic Prefix

In the ALAMOUTI-coded cooperative communication system,an orthogonal frequency division multiplexing （OFDM） technology is used to combat the time delay from relay nodes to the destination,which can be treated as a multipath channel.The inter-symbol interference （ISI） resulting from the time delay,however,cannot be completely eliminated if the length of cyclic prefix （CP） is less than that of the relay time-delay.To solve this problem,a decision feedback equalizer （DFE） is introduced into the ALAMOUTI-coded cooperative OFDM system with insufficient length of CP.Two equalizers are designed based on zero forcing （ZF） criterion and minimum mean square error （MMSE） criterion.Simulation results show that both equalizers can improve the system performance,and the equalizer with MMSE-DFE criterion has optimal performance.