Decoding of Polar Codes for Intersymbol Interference in Visible-Light Communication

In this letter, a modified likelihood ratio (LR) for decoding of polar codes is proposed for the intersymbol interference (ISI) environment, which is a major drawback in visible-light communication. In general, methods to alleviate ISI include equalization and error correction code. Our proposed algorithm focuses on error correction code aspect, where we adopt polar codes to reduce the effect of ISI. In our proposed system, we analyze the detailed effect of ISI and derive that modified LR function, different from the conventional LR function without considering ISI, can efficiently reduce the effect of ISI when it was used as input of decoding, such as list-cyclic redundancy check decoding of polar codes. Simulation results show that our proposed algorithm provides a better bit error rate performance than a referenced algorithm that uses the conventional LR function.