Aiming at the problems of index modulation orthogonal frequency-division multiplexing technology with high peak-to-average ratio,sensitivity to phase noise and carrier frequency,and high system complexity,this paper proposes a visible OFDM-IM system based on wavelet boost transform.Firstly,the orthogonal wavelet group is selected as the subcarrier,and the signal is divided into high-frequency signal and low-frequency signal through the splitting,prediction and update of the signal,and then combined with the visible light channel to form the LWT-OFDM-IM sys-tem,and finally the reliability,peak-to-average ratio characteristics and optimal wavelet decomposition layer of the system are simulated and verified by theoretical analysis and Monte Carlo method,and the results show that when the subcarrier N=256,the number of neutron carriers in the subblock L=4,the number of activated subcarriers k=2,and the system bit error rate is 10-4.LWT-OFDM-IM is about 8 dB better than FFT-OFDM-IM and about 4 dB high-er than DWT-OFDM-IM.When the system complementary cumulative distribution function is 10-1 orders of magni-tude,the peak-average improvement of LWT-OFDM-IM is about 2.3 dB compared with FFT-OFDM-IM.As the number of wavelet layers increases,the better the bit-error performance of the system,when the wavelet layer is 3 lay-ers,it is about 10 dB,and the bit error rate can reach the order of 10-5.
关键词
可见光通信/正交频分复用/提升小波变换/索引调制/峰均比
Key words
visible light communication/orthogonal frequency division multiplexing/lifting wavelet transform/in-dex modulation/peak-to-average
维普
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