宽带OFDM系统中基于部分信道反馈的预处理优化算法

摘要

To mitigate inter-block interference (IBI) and inter-carrier interference (ICI) in an orthogonal frequency division multiplexing (OFDM) system, pre-processing approaches at transmitters based on full channel state information (CSI) had been proposed, the performance improved and receiver simplied. However, feeding full CSI back would occupy scarce bandwidth and was impractical sometimes for the systems with high real-time demand. To deal with this problem, a preprocessing optimization based on partial CSI feedback was investigated and three selected preprocessing approaches of optimization matrix were developed and tested. Computer simulation results showed that the proposed optimization algorithm can effectively cancel IBI and ICI and significantly improve the performance in wideband OFDM systems. Compared with the pre-processing approaches at transmitters based on full CSI, under the condition of meeting the demand for quality of services (QoS), the proposed scheme has high spectral efficiency and low feedback and computation complexity.%为克服OFDM系统中的符号块间干扰(IBI)和载频间干扰(ICI),基于满信道状态信息(CSI)的发端预处理算法已被提出,系统性能得以提高并简化了接收机.不过,反馈满CSI将占用紧张的频谱资源,并且在一些实时性要求高的系统中也是不现实的.为解决这一问题,基于部分CSI反馈提出了一种预处理优化算法,并对优化矩阵的3种处理方案进行了分析与讨论.仿真结果表明,所建议的优化算法能有效地抑制IBI和ICI,提高系统的性能.与已有的基于满信道信息的发端预处理传输方案相比,在满足一定服务质量要求的情况下,本方案的频谱效率得以提高,反馈量和计算复杂度明显降低.