关键词: 可见光通信, 码间串扰, 训练序列, 盲均衡

Abstract: In order to reduce the bit error rate of indoor Visible Light Communication（VLC）, reduce the Intern Symbol Interference（ISI） caused by multipath effect, and improve the transmission characteristics of the system, the blind equalization algorithm of visible light communication system is studied. The channel of indoor visible light communication system is analyzed and modeled, and the impulse response of indoor visible light communication is calculated by an improved impulse response algorithm. Aiming at the equalization algorithm of Least Mean Square（LMS）, which needs training sequence and channel bandwidth, a variable step size Covariance Matrix Adaptation（CMA） blind equalization algorithm based on Sigmoid function is proposed. The experimental results show that using the improved CMA algorithm, the convergence speed is faster, reduce the steady-state error after convergence, the tracking effect of the equalizer system is excellent, the error rate of communication system is greatly decreased, the ability to resist noise interference is significantly improved, and it can effectively improve the inter symbol interference of indoor VLC system.

Key words: Visible Light Communication（VLC）, Intern Symbol Interference（ISI）, training sequence, blind equalization