OFDM联合信道估计与均衡技术研究

OFDM系统在时变信道中会受到子载波间干扰,单独进行信道估计和信号检测的策略对于提高接收机的抗干扰能力有限,将信道估计和信号检测统一考虑则可更有效地抵抗子载波间干扰。针对此问题,基于迭代SAGE算法提出了一种新的联合信道估计与符号检测算法,为了减低算法的复杂度,引入BEM信道建模方法。仿真评估了BEM算法的归一化均方误差性能,验证了BEM建模的有效性,显示该算法的误码率优于基于BEM算法的线性均衡检测算法和基于MMSE的干扰对消算法,而且该算法只通过少数几次迭代便可达到收敛域,较好地克服了子载波间干扰的问题。

Research on Joint Channel Estimation and Equalization Based on OFDM Systems

When used in time-varying channels, OFDM may be influenced by inter-carrier interference （ICI）. The policy of separately implementing channel estimation and signal detection can＇ t significantly improve the anti-interference capability of receiver. The channel estimation and signal detection can be unitedly considered to more effectively resist the sub-carrier interference. Aiming at this point,a novel joint channel estimation and signal detection algorithm is proposed based on SAGE, and BEM channel modeling method is introduced to decrease the complexity. The normalization mean square error performance of BEM algorithm is estimated by simulation and the validity of BEM modeling is proved. The simulation results show that the proposed algorithm is better than linear equalization methods based on BEM and successive interference cancellation based on MMSE, and it can achieve the convergence domain by fewer iterations and better overcome sub-carrier interference.