中国激光, 2016, 43 (9): 0906003, 网络出版: 2018-05-25
MIMO-OFDM可见光通信系统的自适应信道估计 下载: 579次
Adaptive Channel Estimation for MIMO-OFDM Visible Light Communication System
光通信 可见光通信 自适应信道估计 信噪比阈值 通信质量 optical communications visible light communication adaptive channel estimation signal-to-noise ratio threshold communication quality
摘要
针对LED通信系统中信道估计性能低的问题,提出了将正交频分复用(OFDM)系统与多输入多输出(MIMO)技术相结合的可见光通信系统及其基于信噪比的自适应信道估计算法。通过对最小二乘法(LS)、最小均方误差(MMSE)、离散傅里叶变换改进最小二乘法(LS-DFT)、离散傅里叶变换改进最小均方误差(MMSE-DFT)以及分布式压缩感知同步正交匹配追踪(DCS-SOMP)5种信道估计方法的研究,确定了信噪比的临界阈值。当信噪比低于临界阈值时,采用MMSE-DFT算法进行信道估计;当信噪比高于临界阈值时,选用DCS-SOMP算法进行数据重构并恢复信道脉冲响应矩阵。仿真结果表明,当信噪比为1 dB~40 dB时, 所提算法的均方误差得到有效降低(2.95 dB~15 dB),且LED通信系统的通信质量得到提高。
Abstract
To solve the low channel estimation performance of LED communication system, a visible light communication system which combines the orthogonal frequency division multiplexing (OFDM) system with the multiple input multiple output (MIMO) technology and its adaptive channel estimation based on signal-to-noise ratio (SNR) are proposed. The critical threshold of SNR is determined when the five algorithms, i.e., least squares (LS), minimum mean square error (MMSE), least squares-discrete Fourier transform (LS-DFT), minimum mean square error-discrete Fourier transform (MMSE-DFT) and distributed compressed sensing synchronous orthogonal matching pursuit (DCS-SOMP), are analyzed. When SNR is lower than the critical threshold, the MMSE-DFT algorithm is used for the channel estimation, and when SNR is higher than the critical threshold, the DCS-SOMP algorithm is applied to the data reconstruction and the recovery of channel impulse response matrix. Simulation results show that when SNR is 1 dB~40 dB the proposed algorithm can reduce the mean square error (MSE) from 2.95 dB to 15 dB, and improve the LED communication quality.
陈勇, 尹辉, 刘焕淋. MIMO-OFDM可见光通信系统的自适应信道估计[J]. 中国激光, 2016, 43(9): 0906003. Chen Yong, Yin Hui, Liu Huanlin. Adaptive Channel Estimation for MIMO-OFDM Visible Light Communication System[J]. Chinese Journal of Lasers, 2016, 43(9): 0906003.