两种OFDM多普勒估计算法在水声信道中的比较

为了消除多普勒频偏影响,通过水上实验对两种OFDM (Orthogonal Frequency-Division Multiplexing)水声通信多普勒估计算法进行对比。基于拷贝相关时延差估计的多普勒
估计算法结构简单、易于实现;基于空载波的算法较复杂,但精度较高。利用两种方法对相同的实验数据进行多普勒估计和补偿，并对其通信误码率进行对比。研究结果表明，在慢变的信道中两者的误码率基本相同，但在快变的信道中基于空载波的算法更稳定。

Comparison Two Dopplor Estimation Algorithms of OFDM in Underwater Acoustic Channels

In order to compare the advantage and shortcoming of two Doppler estimation algorithms for OFDM（Orthogonal Frequency-Division Multiplexing） in underwater acoustic communication,a lacustrine experiment was carried out.The replica correlation time delay difference estimation algorithm is simple and easy to achieve,and the null subcarriers algorithm is complex and accurate.The same experimental dates are estimated and compensated based on the two algorithms,and error bit rates are compared.The results show that the two methods have mainly uniform error bit rates in slow varying UWA(Underwater Acousitic)channels,but the null subcarriers algorithm is more stable in fast time-varying channels.