基于非均匀快速傅里叶变换的正交频分复用水声通信多普勒估计与补偿方法

针对正交频分复用水声通信对多普勒频移敏感的问题,提出了一种基于非均匀快速傅里叶变换的正交频分复用水声通信多普勒估计与补偿算法.将第2类非均匀快速傅里叶变换引入正交频分复用水声通信中,利用非均匀快速傅里叶变换对接收信号进行多普勒因子网格补偿,通过稀疏贝叶斯学习获得水声信道估计,以水声信道的稀疏能量最小作为多普勒因子判断准...

Doppler estimation and compensation method for orthogonal frequencydivision multiplexing underwater acoustic communication basedon non-uniform fast Fourier transform

Aiming at the problem that the orthogonal frequency division multiplexing (OFDM) underwater acoustic communication issensitive to Doppler frequency shift, a Doppler estimation and compensation algorithm for OFDM underwater acoustic communicationbased on non-uniform fast Fourier transform ( NUFFT) is proposed. The type-2 NUFFT technique is introduced into the OFDMunderwater acoustic communication and utilized to perform Doppler factor grid compensation on the received signal. And the estimation ofunderwater acoustic channel is obtained through the sparse Bayesian learning. Then the minimum sparse energy of the underwateracoustic channel is used as the Doppler factor judgment criterion to obtain a high-precision Doppler estimation. Simulation results showthat when the signal to noise ratio (SNR) is greater than 5 dB, the root mean squared error (RMSE) of the proposed method is betterthan 1×10-5. And the bit error rate (BER) of the system decreases with the decrease of the RMSE of Doppler estimation. The results ofthe sea trial show that the relative radial velocity between the two ships obtained with the proposed Doppler estimation method isconsistent with the actual situation. And the average BER after decoding is better than 8. 33 × 10-4. Simulation and sea trial resultsdemonstrate that the proposed algorithm can effectively estimate Doppler factor and reduce the system bit error rate.