OFDM压缩感知信道估计中的导频优化.pdf

IEEE SIGNAL PROCESSING LETTERS, VOL. 18, NO. 12, DECEMBER 2011 749 Optimized Pilot Placement for Sparse Channel Estimation in OFDM Systems Chenhao Qi, Member, IEEE, and Lenan Wu Abstract— Compressed sensing (CS) has recently been applied search the pilot placements before transmission. Since well-es- for pilot-aided sparse channel estimation. However, the design of tablished channel models are usually available in wireless the pilot placement has not been considered. In this letter, we pro- communications, it’s beneficial to take advantage of them pose a scheme using the modified discrete stochastic approxima- for pilot optimization at the transmitter. Even for underwater tion to optimize the pilot placement in OFDM systems. The channel data is employed to offline search the near-optimal pilot placement acoustic communications [7], a collection of sampled real before the transmission. Meanwhile we also get a criterion to select channel data of specific sea area is accessible. Besides, our CS algorithms based on the mean squared error (MSE) minimiza- scheme also presents a criterion to select CS algorithms based tion. Simulations using a sparse wireless channel model have val- on the mean-squared error (MSE) minimization. idated the effectiveness of the proposed scheme, which is demon- The remainder of the letter is organized as follows. Section II strated to be much faster convergent and more efficient than the exhaustive search. It has been shown that substantial performance briefly describes the mo