基于压缩感知的非整数点多径信道估计算法

Channel estimation based on compressive sensing for non-integral delay channel

摘要:

基于压缩感知的稀疏信道估计充分利用无线信道的时域稀疏特性,大大降低正交频分复用(OFDM)波形设计时信道估计占用的导频数,提升带宽利用率．针对实测信道中普遍存在的非整数采样点时延的多径干扰,提出了一种基于噪声判决的高采样精度压缩感知信道估计算法,通过改进压缩感知测量矩阵和引入噪声估计判决,有效抵抗由非整数点时延多径引起的能量泄漏．仿真结果表明,相较于传统压缩感知信道估计算法,本算法能有效抵抗OFDM实用数字传输系统中的非整数采样点多径影响,性能具有明显优势．

Abstract:

Taking full advantage of the time-domain-sparsity of wireless channel, orthogonal frequency division multiplexing (OFDM) sparse channel estimation based on compressive sensing (CS) reconstructs accurate channel information using few pilots. By improving the CS measurement matrix and using judgment of noise estimation, a novel CS channel estimation algorithm opposes the non-integral delay multipath existed in actual OFDM systems and this algorithm effectively combats the energy leakage caused by non-integral delay multipath. Simulations show that the novel algorithm has better performance than the original CS channel estimation algorithm, and it resists the non-integral delay multipath in OFDM digital transmission systems more effectively.