摘要
针对IEEE802.16d帧结构提出一种结合前导训练序列和导频的信道估计算法。算法通过前导完成初始精确的信道估计,再使用判决反馈方式提高导频估计准确度,并根据前后符号导频估计结果得到反映信道变化的时变因子,利用它来调整前导估计和导频估计比例,联合完成信道估计。仿真结果表明,与传统的信道估计方法相比,此算法能够更有效的对抗频率选择性衰落和更大的多普勒频移,改善系统的性能。
According to the frame structure of IEEE802.16d, a channel estimation algorithm based on the combination of preamble training sequences with pilots is proposed. The algorithm utilizes preamble to obtain the initial accurate channel estimation and then enhances the pilot-aided channel estimation accuracy by using decision feedback structure. Furthermore, according to the results estimated by pilots in adjacent OFDM symbols, a time-variable factor that reflects the channel changes is obtained to adjust the proportion of the results estimated by preamble training sequences and pilots. Simulation results show that, as compared with the original method, the method proposed in this paper could effectively achieve a better performance against frequency selective fading and higher Doppler frequency shift.
出处
《通信技术》
2010年第2期222-224,共3页
Communications Technology
