CAJ | 학술논문

针对稀疏多径的水声OFDM信道,提出了基于叠加训练序列的信道估计方法,能够提高带宽传输效率.在发送端的信息序列中叠加一个低功率的周期性训练序列,在不占用额外的信号带宽的情况下估计信道参数,未知的信息序列会对叠加训练序列的信道估计方法产生干扰,在本文中采用迭代方法提高估计性能.水声信道具有延时时间长,信道稀疏的特点,本文采用匹配跟踪的方法估计信道非零系数的位置,降低加性白噪声对信道估计的影响.仿真结果显示,本文的方法能达到很好的信道估计性能,同时能够降低OFDM的峰均比.
침대희소다경적수성OFDM신도,제출료기우첩가훈련서렬적신도고계방법,능구제고대관전수효솔.재발송단적신식서렬중첩가일개저공솔적주기성훈련서렬,재불점용액외적신호대관적정황하고계신도삼수,미지적신식서렬회대첩가훈련서렬적신도고계방법산생간우,재본문중채용질대방법제고고계성능.수성신도구유연시시간장,신도희소적특점,본문채용필배근종적방법고계신도비령계수적위치,강저가성백조성대신도고계적영향.방진결과현시,본문적방법능체도흔호적신도고계성능,동시능구강저OFDM적봉균비.
A superimposed training (ST) based channel estimation method is presented that provides accurate estimation of a sparse underwater acoustic orthogonal frequency-division multiplexing (OFDM) channel while improving bandwidth transmission efficiency. A periodic low power training sequence is superimposed on the information sequence at the transmitter. The channel parameters can be estimated without consuming any extra system bandwidth, but an unknown information sequence can interfere with the ST channel estimation method, so in this paper, an iterative method was adopted to improve estimation performance. An underwater acoustic channel's properties include large channel dimensions and a sparse structure, so a matching pursuit (MP) algorithm was used to estimate the nonzero taps, allowing the performance loss caused by additive white Gaussian noise (AWGN) to be reduced. The results of computer simulations show that the proposed method has good channel estimation performance and can reduce the peak-to-average ratio of the OFDM channel as well.