Analysis of BPSK Modulation Technique in Visible Light Communication Systems

Visible Light Communication (VLC) is a data transmission technology utilizing LED light sources, offering advantages such as high bandwidth and electromagnetic interference immunity. Binary Phase Shift Keying (BPSK), as a fundamental modulation scheme, plays a crucial role in VLC systems. In code implementation, BPSK can be realized using signal processing libraries with functions like pskmod() in MATLAB or equivalent phase-shifting algorithms.

BPSK modulation transmits binary information by altering the phase of optical signals - typically using 0° phase for "0" and 180° phase for "1". Since visible light communication predominantly employs Intensity Modulation/Direct Detection (IM/DD), practical implementation requires indirect mapping of phase information through light intensity variations. This can be achieved programmatically by converting phase changes to amplitude variations using trigonometric functions (e.g., cos(phase) for intensity conversion) in the modulation algorithm.

The advantages of applying BPSK in VLC systems include strong noise resistance and simple implementation structure. However, due to the unique characteristics of optical communication channels (such as multipath effects and background light interference), its bit error rate performance experiences certain degradation. Theoretical analysis and experimental testing reveal that BPSK's error rate increases significantly at low signal-to-noise ratios, yet it maintains advantages over simpler modulation schemes like OOK (On-Off Keying). Error rate calculations can be implemented using communication toolbox functions like berawgn() for theoretical performance comparison.

Future enhancements could integrate equalization techniques or higher-order modulation schemes to further improve BPSK performance in VLC systems, potentially implemented through adaptive filtering algorithms or M-PSK modulation extensions in the communication chain.