（信息科學與技術國家實驗室,清華大學 北京100084）
摘要：針對時變信道環境，本文研究了訓練序列的插入方式和信道估計算法。我們分析了時分復用訓練序列和疊加訓練序列兩種方式，研究了它們各自的特點和適用環境，并基于維納濾波和卡爾曼濾波研究了相應的信道估計算法；最后搭建了基于兩種訓練序列的信道估計仿真平臺，比較了兩種不同的訓練序列的性能。仿真結果表明，在多普勒頻移較大或者信噪比較低(<5dB)的情況下，疊加訓練序列的性能要優于時分復用訓練序列的性能。
關鍵詞：疊加訓練序列；時分復用訓練序列；信道估計
中圖分類號：□□□□□ 文獻標識碼：A 文章編號：
Study on Pilot Scheme and Channel Estimation
ZHANG Chun-yang, CHEN Jin-Xiu, WANG You-zheng
�。═singhua National Laboratory for Information Science and Technology (TNList), Tsinghua University,
Beijing 100084, P. R. China. Correspondence Address: WANG You-zheng: yzhwang@tsinghua.edu.cn）
Abstract：The pilot scheme and channel estimation alogorithms are studied for the timing-varing fading channel. Here, we focus on two kinds of pilot insertion schemes, known as the time multiplexing sequence and superimposed sequence, and make comparison on between them. The channel estimation alogirthms based on Wiener filter and Kalman filter are also analyzed for them. We built the simulatio platform to evaluate them. Simulation results show that the superimposed sequence is more suitable for bigger Doppler shift cases and lower signal to noise ratio environment than the time multiplexing sequence.
Key words：Time multiplexing；Superimposed Sequence; Kalman filter; Channel estimation
參考文獻 (References)
[1] Adireddy S., Tong L., and Viswanathan H., “Optimal placement of known symbols for frequency-selective block- fading channels,” IEEE Trans. Info. Theory, vol. 48, pp. 2338–2353, August 2002.
[2] L Tong, B Sadler, M Dong. Pilot-assisted wireless transmissions: General model, design criteria, and signal processing. IEEE Signal Processing Magazine, 2004,21(6):12-25
[3] F. Mazzenga, “Channel estimation and equalization for M-QAM transmission with a hidden pilot sequence,” IEEE Trans. on Broadcasting, vol. 46, p. 170176, June 2000
[4] C. Budianu and L. Tong, “Channel Estimation for Space-Time Block Coding Systems,” IEEE Trans. Signal Processing, vol. 50, pp. 2515–2528, Oct 2002
[5] Tugnait J. K. and Luo W., On channel estimation using superimposed training and first-order statistics. in Proceedings of ICASSP '03, vol. 4, pp. 624-627, Hong Kong, April 2003
作者簡介：
張春陽（1987-），男，碩士研究生，研究方向為信道估計，無線網絡技術。
陳金秀（1989-），女，碩士研究生，研究方向為自適應傳輸技術。
王有政（1969-），男，副研究員，研究方向為衛星通信、衛星廣播和空間信息網絡。
