自适应OFDM系统的时域信道预测研究

针对自适应OFDM系统,提出了一种新型时域信道预测策略。该策略利用递归量化分析方法,量化并估计信道脉冲响应中每个时延抽头的局部可预测性,然后利用每个时延抽头的局部可预测性筛选出信道脉冲响应中重要的时延抽头;最后,利用基于联合回声状态网络的信道预测器实现各个重要时延抽头的信道预测。在仿真部分,利用基于IEEE802.11ah协议的OFDM系统来评估系统的性能。仿真结果表明,通过递归量化分析,发射端可以准确地筛选出信道脉冲响应中重要的时延抽头。除此之外,联合回声状态网络可以产生稀疏的输出权值;而且,由于具有oracle属性,提出的联合回声状态网络在基本的回声状态网络的基础上有91.57%的预测性能提升。

Research of the time-domain channel prediction for adaptive OFDM systems

In this paper, a novel time-domain channel prediction technique for adaptive OFDM systems is introduced. The novel timedomain channel prediction technique utilizes the RQA to quantify and estimate the local predictability of each time-delay tap in the channel impulse response, and then based on the local predictability of each delay tap, we select those significant time-delay taps in the channel impulse response; finally, the joint echo state network ( JESN) is utilized to predict the channel state information in each significant time-delay tap. In the simulation part, the OFDM system based on the IEEE802. 11ah standard to evaluate the performance. The simulation results show that by the TSS-RQA, those significant time-delay taps in the channel impulse response are accurately selected. In addition, the JESN produces the sparse output weight matrix. Due to the oracle property, the improved prediction performance of the JESN is approximate to 91. 75%, compared to the basic echo state network.