基于格雷对辅助的OFDM系统联合同步与信道估计算法

Golay Pair Aided Joint Synchronization and Channel Estimation Scheme for OFDM Systems

设计了一种新的训练符号,并提出了相应的数据辅助的OFDM系统联合同步与信道估计算法。利用格雷对非周期自相关互补特性,在时域执行同步过程中得到放大的信道冲激响应样值。通过设定一个门限值,在小搜索窗内通过检测第一抽头位置,从而进一步提高同步精度,并同时得到信道冲激响应估计值。算法分析和仿真结果表明,提出的符号定时函数能有效对抗恶劣多径瑞利衰落的影响,并且避开了求矩阵广义逆等运算,以较低的系统开销获得了良好的时域信道估计性能。

A new training symbol was designed and a corresponding data-aided joint synchronization and channel estimation scheme for orthogonal frequency division multiplexing（OFDM） systems was proposed. By utilizing the aperiodic auto-correlation complementary property of the golay pair, the fine timing point and the magnified channel impulse response（CIR） samples were obtained at the same time in time domain. The magnified CIR samples were exploited for the timing accuracy further improvement by using a threshold factor for the first channel tap detection in a small search window. Meanwhile, the estimated CIR samples were obtained. The algorithm analysis and computer simulation results show that the proposed timing synchronization method is robust to severe multipath Rayleigh fading environment,and without Moore-Penrose pseudoinverse operation, it can get well channel estimation performance in time domain with low system overhead.