OQAM/OFDM系统中基于压缩感知的离散导频信道估计方法

Scattered pilots aided channel estimation based on compressed sensing in OQAM/OFDM system

针对多径信道条件下,偏移正交幅度调制的正交频分复用(OQAM/OFDM)系统中采用导频序列方式进行信道估计时导频开销较大的问题,提出一种基于压缩感知的离散导频信道估计方法。该方法利用无线信道的稀疏特性,建立基于压缩感知的OQAM/OFDM系统信道估计模型,对离散导频结构进行了优化设计,使较少的导频符号随机分布在子载波上,在接收端利用信号恢复算法实现信道估计。该方法能够显著减少导频数量,并实现高精度信道估计性能,通过实验仿真对比验证了所提方法在慢时变和快时变的无线信道条件下的有效性。

Under the multi-path channel condition,the preamble-based channel estimation methods have very large pilots overhead in OQAM/OFDM(offset quadrature amplitude modulation/orthogonal frequency division multiplexing).To solve this problem,a scattered pilots aided channel estimation method based on the compressed sensing for OQAM/OFDM system was proposed by utilizing the sparsity of wireless channel.The principle of OQAM/OFDM channel estimation method based on compressed sensing was established and a scattered pilots pattern,which deploys pilots symbols on few subcarriers randomly,was also designed.The proposed method can reduce the pilots overhead significantly and realize the highly accurate channel estimation.The simulation results validate the efficacy and the superior performance of the proposed method in both slow and fast time-varying wireless channel.