时间-频率双选择性衰落信道的最小二乘估计方法
doi: 10.3724/SP.J.1146.2007.00301
Least Square Estimation of Doubly Selective Wireless Fading Channels
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摘要: 高速移动下的无线宽带通信要经历时间和频率双选择性衰落，信道估计质量的好坏对整个系统的性能有重要的影响。该文利用复指数基扩展模型，提出一种基于最小二乘的时频双选信道估计方法，接收机不需要信道的统计信息，也不需要预先估计噪声方差，接收机复杂度较低；在该信道估计算法的基础上，基于信道估计均方误差最小准则，分析并推导出优化的训练序列所要满足的条件。仿真结果表明，在由Jakes模型产生的时频双选衰落信道下，在一定的信噪比范围内，该文方法的信道均方误差性能优于现有的方法。Abstract: High data rates and high mobility induced Doppler shifts introduce time and frequency selectivity in wireless links. The quality of channel acquisition has a major impact on the overall system performance. In this paper, relying on a basis expansion channel model, a scheme is proposed for estimating doubly selective channel parameters . The receiver does not have to know the statistic information of the channels and will not estimate the power of noise in advance, and has low-complexity. Along with the estimation scheme, the optimal pilot sequence is derived based on minimizing mean-square error of the channel estimation. Simulation results demonstrate the performance of the proposed scheme is better than existing scheme for a range of SNR, where a frequency- selective channel is randomly generated with different Doppler spreads via Jakes model.
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[1] Choi Y S, Voltz P J, and Cassara F A, On channel estimationand detection for multicarrier signals in fast and selectiveRayleigh fading channels. IEEE Trans. on Commun., 2001,49(8): 1375-1387. [2] Schniter P. Low-complexity estimation of doubly selectivechannels. In Proc. IEEE Workshop Signal ProcessingAdvances in Wireless Commun., Rome, Italy, June 15-18,2003: 200-204. [3] Cavers J K. An analysis of pilot symbol assisted modulationfor Rayleigh fading channels. IEEE Trans. on VehicularTechnology, 1991, 40(4): 686-693. [4] Ma Xiaoli, Giannakis G B, and Ohno S. Optimal training forblock transmissions over doubly-selective wireless fadingchannels. IEEE Trans. on Signal Proc. 2003, 51(5): 1351-1366. [5] Giannakis G B and Tepedelenlioglu C. Basis expansionmodels and diversity techniques for blind identification andequalization of time varying channels[J].Proc. IEEE.1998,86(10):1969-1986 [6] Tsatsanis M K and Giannakis G B. Equalization of rapidlyfading channels: Self-recovering methods[J].IEEE Trans. onCommun.1996, 44(5):619-630 -
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