OFDM水声通信多普勒频移采样率转换算法

摘要

To the Orthogonal Frequency Division Multiplexing(OFDM) Underwater Acoustic(UWA) communication systems, the traditional estimation algorithm based on data aided for Doppler Shift Factor(DSF) can reduce the system transmission rate. In addition, resampling algorithm is often used for the sample rate conversion in the receiving end, but there is a problem of large calculation in the process. Therefore, a novel algorithm about DSF estimation and sample rate conversion are proposed based on oversampling technique. The DSF can be estimated by comparing the sampling points with the transmitting and receiving signals. And the linear interpolation algorithm is adopted to finish the sample rate conversion. Theroy analysis and simulation results show that the algorithm not only can guarantee the system performance but also can reduce the receiver calculation amount. So it is applicable to the high-speed real-time UWA com-munication systems.%对于OFDM水声通信系统，传统的基于数据辅助多普勒频移因子估计算法会降低系统的信息传输速率，对接收信号进行采样率转换通常采用重采样的方法，计算量较大。针对上述问题，提出基于过采样技术的多普勒频移因子估计算法及采样率转换算法，通过采用对系统发射信号与接收信号采样点数进行比较的方法，得到多普勒频移因子的估值。在此基础上，利用上述过采样数据和线性插值算法对接收信号进行采样率的转换。理论分析和仿真结果表明，改进算法在保证系统性能的同时，可以大幅减小接收机的计算量，适用于高速实时水声通信系统。