SOCP Approach for OFDM Peak-to-Average Power Ratio Reduction in the Signal Adding Context

Orthogonal frequency division multiplexing (OFDM) is an attractive technique for wireless communications applications. However, one of the main disadvantages of OFDM is its high peak to average power ratio (PAPR) that limits transmitter power efficiency. Without any measures, the OFDM signal is limited by the power amplifier (in the transmitter) what causes interference both on the signal itself and in adjacent frequency bands. In this paper we formulate the reduction of the PAPR problem as a second order cone programming problem (convex optimization). We extend two known methods by choosing unused carriers in standards to minimize PAPR. The results are presented for the 802.11a standard. The proposed method induces no in-band distortion and stay compatible towards the IEEE 802.11a spectrum masking. Moreover, they don´t need any side information and can be applied for real or complex OFDM baseband