Extended modulation mappings for hybrid ARQ in wireless communication systems

This paper discusses an extended modulation mapping technique to improve hybrid automatic repeat request (ARQ) protocols by reducing communication errors in wireless systems. The extended mapping (EM) hybrid ARQ (HARQ) protocol has been developed using irregular repetition code with turbo processing. This protocol uses EM and ARQ to improve efficiency, including retransmission for error correction. The existing hybrid ARQ technique uses a horizontal iterative decoding scheme to reduce error. The suggested method employs both serial and parallel iterative decoding schemes for error detection and correction. A bit error rate (BER) analysis evaluates the proposed model, EM-HARQ performance in the additive white Gaussian noise channel. The results show a significant gain in signal-to-noise ratio (SNR) from the theoretical limit of the irregular repetition coding using MATLAB simulation software. The adoption of EM in the proposed method improves the SNR to a 0.99 dB performance gap difference and 0.3 dB performance gain due to enhanced error detection. Even with low SNR channels, the proposed EM-HARQ system can achieve a low BER and close to the theoretical limit capacity.