Doppler Shift Based Sampling Rate Conversion for GFDM Underwater Acoustic Communication

In Generalized Frequency Division Multiplexing (GFDM) underwater acoustic communication systems, the conventional Doppler shift factor estimation will reduce the transmission rate of the system. The sampling rate conversion of the received signal usually adopts the resampling method, thereby increasing the computational complexity. Aiming at the above problems, a Doppler shift factor (DFS) estimation algorithm based on oversampling technique and a sampling rate conversion algorithm is proposed. The Doppler shift factor is estimated by comparing the transmitted signal with the received signal samples. On this basis, the above-sampled data and a linear interpolation algorithm are used to convert the sampling rate of the received signal. The theoretical analysis and simulation results show that the improved algorithm can greatly reduce the computational complexity of the receiver while ensuring the performance of the system and is suitable for high-speed real-time underwater acoustic communication systems.