SOCP Approach for Reducing PAPR for MIMO-OFDM Via Tone Reservation

Abstract

A combination of multiple-input multiple-output with orthogonal frequency division multiplexing has become a promising candidate for wireless communications. However, like OFDM, a serious disadvantage of the MIMO-OFDM system is the high Peak to Average Power Ratio (PAPR), which may severely affected the power efficiency of RF power amplifiers. In this paper, we proposed a novel method to reduce the PAPR based on the use of unused subcarriers. Accordingly, we formulated the reduction of the PAPR problem as space-time block codes approach (convex optimization). The reduction method is originally based on a particular case of Tone Reservation approach which uses the unused carriers of standards. Indeed, this approach does not degrade the bit-error-rate or the data rate and no side information is required. Besides, our approach is relatively simple, robust and precise and it achieved significant reduction in PAPR. In fact, we validated our approach on the WiMax systems and we compared our results with those found in the literature. Consequently, our proposed approach improved a PAPR reduction about 5 dB at the 10 -3 probability level. In addition, and precisely when using CCDF of signal technique optimized with constraint mean power vs. �, the PAPR was reduced about 6dB. However and with previously works, a PAPR reduction has been obtained about 2.5 dB.