Performance Improvement in MIMO-OFDM VLC Systems Through Combined Adaptive Modulation and Coding with Symbol Decomposition

In the visible light communication (VLC) system, adaptive symbol decomposition technology is one of the methods to reduce peak-to-average power ratio (PAPR) and suppress LED nonlinear distortion. However, at high symbol variances, there still exists a high PAPR, leading to a higher number of decomposed symbols, which in turn reduces the information rate and increases the bit error rate (BER) performance. Therefore, a combined approach of adaptive modulation, adaptive symbol decomposition serial transmission (ASDST), and space–time block code and orthogonal cyclic matrix transform (STBC-OCT) coding is proposed. The characteristics of PAPR, symbol decomposition and BER under different approaches through Monte Carlo simulation were analyzed. The simulation results show that when using 4-Quadrate Amplitude Modulation (4QAM) modulation and CCDF=[Formula: see text], the STBC-OCT-ASDST scheme gains a 5[Formula: see text]dB improvement compared to ASDST alone. At a BER of [Formula: see text], STBC-OCT-ASDST achieves a 10[Formula: see text]dBm gain in symbol variance compared to ASDST. Moreover, when the symbol variance of STBC-OCT-ASDST is less than 34[Formula: see text]dBm, the BER remains below the 7% threshold of forward error correction (FEC) error rate.