Novel Decision-Directed Channel Estimation Method for TDS-OFDM System
Time-domain synchronous orthogonal frequency division multiplexing system (TDS-OFDM) employs known pseudonoise (PN) sequences as guard interval padding between adjacent OFDM symbols. Accurate estimation of channel impulse response (CIR) is dif.cult but very important to recover transmitted OFDM symbols by subtracting padded PN sequences. Conventional channel estimation methods only use PN sequences as the training sequences to obtain CIR. Actually, decision-directed channel estimation (DDCE) method which takes advantage of the fact that M-QAM modulated subcarriers in OFDM symbol also contain much valuable hidden-information due to regular constellation mapping and can be used to improve the accuracy of channel estimation. In this paper, the accuracy of channel estimation based on both PN sequence and OFDM symbol is investigated. Moreover, a novel DDCE method based on an accurate initial CIR obtained from two consecutive training sequence and partial decision results of OFDM subcarriers for TDS-OFDM system is proposed. Simulation results show that the proposed algorithm works well over the slow-varying frequencyselective fading channel.
Fang Yang Kewu Peng Jian Song Changyong Pan Zhixing Yang
Tsinghua National Laboratory for Information Science and Technology (TNList)Department of Electronic Engineering,Tsinghua University,Beijing 100084,China
国际会议
广州
英文
2008-11-19（万方平台首次上网日期，不代表论文的发表时间）