OFDM based visible light communication with probabilistic shaping

A visible light communication (VLC) system using probabilistically shaped orthogonal frequency multiplexed (OFDM) modulation is presented. The average symbol energy of probabilistically shaped OFDM modulation is investigated for different modulation orders of quadrature amplitude modulation (QAM) under different entropy scenarios. Furthermore, the symbol error performance of the probabilistically shaped OFDM system under additive white Gaussian noise (AWGN) channel condition is evaluated. The probabilistically shaped OFDM system outperforms the uniformly distributed in the symbol error ratio performance. For 256-QAM with an entropy of 7.84 bits, we have shown a 3 dB gain in signal-to-noise ratio (SNR) per symbol compared to uniform 256-QAM at a symbol error ratio of 10-3. This gain increases to 5.5 dB by decreasing the entropy to 6.80 bits.