Reed-Muller Codes in Error Correction in Wireless Adhoc Networks

The IEEE 802.11a standard uses a coded orthogonal frequency division multiplexing (COFDM) scheme in the 5-GHz band to support data rates up to 54 Mbps. The COFDM was chosen because of its robustness to multipath fading affects. In the standard, convolutional codes are used for error correction. This thesis examines the performance of the COFDM system with variable rate Reed-Muller (RM) error correction codes with a goal to reduce the peak-to-average power ratio (PAPR). Contrary to the expectations, RM codes did not provide expected improvement in PAPR reduction. Peak clipping and Hanning windowing techniques were investigated in order to reduce the PAPR. The results indicate that a tradeoff exists between the PAPR and the bit-error rate (BER) performance. Although peak clipping yielded considerable reduction in PAPR, it required high signal-to-noise ratios. On the other hand, Hanning windowing provided only a small reduction in PAPR with reasonable BER performance.