PAPR Reduction in MIMO-OFDM Based on Polar Codes and Companding Technique

摘要

MIMO-OFDM is a method adopted by new highspeed communications technologies such as IEEE802.11, IEEE 802.16 and 4G. Among the advantages of MIMO-OFDM, its ability to increase the transmission rate, and its adaptation to multipath channel with fading. Unfortunately the signals modulated by the OFDM technique generate high values of Peak-to-Average Power Ratio (PAPR). To solve this major drawback, several techniques have been proposed in literature. Among others, we find those that combine coding and companding. In this context we propose and study a new method based on μ-Law companding type and Polar Codes to reduce PAPR values in a MIMO-OFDM system. In order to evaluate the performances of our method in terms of PAPR and BER, several simulations are performed taking into consideration parameters related to coding and companding rates, and the number of sub carriers. The plotted curves show that the results are very significant; indeed, firstly our method achieves a gain of 8 dB in terms of PAPR by ensuring a good compromise in term of BER thanks to the use of the Polar Codes. Secondly our method operates with less complexity and outperforms the most well-known methods.