水声信道中的迭代分组判决反馈均衡器

 与传统的时域均衡相比，频域均衡为单载波传输系统提供了一种计算更为有效的方法。该文对有大多径时延和多普勒频移的水声信道中的频域分组迭代判决反馈均衡器(IB-DFE)进行了研究，提出了一种联合迭代均衡和频域信道估计(JECE)算法，分析了JECE算法的性能以及不同数据参数对IB-DFE性能的影响，并计算了IB-DFE的计算复杂度。仿真结果表明，所提出的JECE算法对时变水声信道有更好的适应性。与TD-DFE相比，IB-DFE有3.6 dB以上的信噪比增益和约19%的复杂度增益，而且随着多径时延和多普勒频移的增加，这种性能增益会进一步增加。

Iterative Block Decision Feedback Equalization for Underwater Acoustic Channels

Frequency-domain equalization for single-carrier transmission systems provides an attractive design alterative to time domain equalization because of more efficient calculation. In this paper an Iterative Block Decision Feedback Equalization (IB-DFE) scheme for communication systems over UnderWater Acoustic (UWA) channels with long delay and Doppler frequency shifts is researched and a frequency domain channel estimation algorithm Jointing iterative Equalization and Channel Estimation (JECE) is proposed. The performance of JECE algorithm is evaluated and compared. The influences of different data parameters on the performance of IB-DFE are analyzed and the computational complexities of IB-DFE are calculated. Numerical results show that the proposed JECE algorithm is more adaptive to the time-varying UWA channels. Compared with Time Domain Decision Feedback Equalization (TD-DFE), IB-DFE has more than 3.6 dB signal-to-noise ratio gain and 19% complexity gain and these gains will extend as the increasing of delay and Doppler frequency shifts of UWA channels.