认知无线电NC-OFDM系统中基于压缩感知的信道估计新方法

摘要

A new channel estimation based on compressive sensing (CS) in non-contiguous orthogonal frequency division multiplexing (NC-OFDM) system was proposed. As for NC-OFDM systems in cognitive radio context, the infrastructure of CS-based channel estimation, the design of pilot patterns and the algorithm of channel estimation were explored. Especially, a criterion of optimizing pilot pattern in the CS-based channel estimation was proposed by minimizing the mutual coherence of the measurement matrix in CS theory. Simulations show that, under many patterns of deactivated sub-carriers, CS-based channel estimation obtains much better performance than existing NC-OFDM channel estimation methods in terms of the mean square error of the channel estimate as well as the bit error rate of the system.%提出了一种基于压缩感知(CS,compressive sensing)理论的不连续子载波正交频分复用(NC-OFDM,non-contiguous orthogonal frequency division multiplexing)系统信道估计新方法,全面研究了认知无线电NC-OFDM系统CS信道估计的理论框架、导频图案的设计、信道估计算法,并依据CS测量矩阵设计理论提出了测量矩阵互相关最小化的导频图案优化准则.仿真结果表明,同已有的NC-OFDM系统信道估计方法相比,CS信道估计能够在多种禁用子载波场景下,使用较少导频获得很好的信道估计性能.