OFDM水声通信系统动态OMP信道跟踪算法

针对正交频分复用(Orthogonal Frequency Division Multiplexing, OFDM)水声通信系统中最小二乘(Least Square,LS)信道估计算法和静态压缩感知信道估计算法分别存在估计精度低、导频开销大和计算复杂度高、实时性差的缺点,利用水声信道冲激响应的时域相关性,通过建立动态稀疏观测模型,提出一种动态正交匹配追踪(Dynamic Orthogonal MatchingPursuit,D-OMP)信道跟踪算法。该算法仅在初始时刻进行一次完整的正交匹配追踪(OrthogonalMatching Pursuit, OMP)信道估计获取信道支撑集,之后通过连续跟踪前一时刻信道支撑集的变化来跟踪信道。仿真结果表明,在导频开销相同的情况下,与传统LS算法、经典OMP算法相比,所提算法具有更好的信道跟踪性能和较低的算法复杂度。

Dynamic OMP channel tracking algorithm for OFDM underwater acoustic communication systems

For the OFDM underwater acoustic communication systems, the least square (LS) channel estimation algorithm has the disadvantages of low estimation accuracy and high pilot overhead, while the static compressive sensing channel estimation algorithm has the disadvantages of high computational complexity and poor real-time performance. Aiming at these problems, a new algorithm called dynamic orthogonal matching pursuit (D-OMP) is proposed by establishing a dynamic sparse observation model based on the temporal correlation of the underwater acoustic channel impulse response. The algorithm only performs a complete OMP channel estimation at the initial time to obtain the channel support set, and then tracks the channel by continuously tracking changes in the previous channel support set. The simulation results show that the proposed algorithm has better channel tracking performance and lower algorithm complexity compared with the traditional LS algorithm and the classical OMP algorithm under the same pilot overhead.