针对基于傅里叶变换光正交频分复用(FFT-OFDM)的非正交多址可见光通信(NOMA-VLC)系统存在可靠性低、用户公平性差等问题, 提出将提升小波变换(LWT)作为载波调制方式, 建立基于LWT-OFDM的NOMA-VLC系统, 介绍了系统中的信号处理过程, 构建了5 m×5 m×3 m的室内空间实验环境。实验结果表明: 与基于FFT-OFDM的NOMA-VLC系统相比, 随着正交幅度调制方式的阶次由4增大到64, 所提系统的平均误码率达到阀值3.8×10-3时, 所需的信噪比(SNR)值较低, 至少低4.4 dB; 用户性能差异变化不明显甚至不变。

Aiming at the problems of low reliability and poor user fairness in non orthogonal multiple access visible light communication(NOMA-VLC) system based on Fourier transform optical orthogonal frequency division multiplexing(FFT-OFDM), a carrier modulation method called lifting wavelet transform(LWT) is proposed to establish a NOMA-VLC system based on LWT-OFDM. The signal processing process in the system is introduced, and an indoor space experiment environment of 5 m×5 m×3 m is constructed. The experimental results show that compared with the NOMA-VLC system based on FFT-OFDM, when the order of orthogonal amplitude modulation increases from 4 to 64, the required signal to noise ratio(SNR) value is lower, at least 4.4 dB lower, when the average bit error rate of the proposed system reaches the threshold of 3.8×10-3. User performance differences do not change significantly or even remain unchanged.