Multi-Patterns-Based Peak to Average Power Ratio Reduction in OFDM Systems

Relative immunity to fading, less susceptible to interference and signal integrity are the main advantages of OFDM compared to the single-carries systems. However, the Peak to Average Power Ratio PAPR is one of the aspects that need to be considered. PAPR is the relation between the highest sub-carries power in a given OFDM symbol divided by the average power of that symbol. Therefore, it has a major effect on the power amplifiers performance by producing inter-modulation products among the sub carriers as well as disturbs out of band energy. In this work, an efficient method to minimize PAPR in OFDM systems, without any side information transmission, is presented. The main idea is to produce different patterns of the same data. Then, these patterns are to be compared with each other in order to send the pattern which has the least PAPR. The identity of each pattern will be inserted with data sub-carriers to recover the original information at the receiver side. Computer simulation tests have been performed on a standard OFDM system to examine the effect of the proposed technique on the PSK and QAM (with 64 sub carriers) based transmissions. The proposed technique is examined in the presence of AWGN and Rayleigh channel effects. The results show the ability of the proposed method to minimize the PAPR without affecting the BER performance. A 3–4 dB reduction in PAPR is achieved using this technique compared to the conventional OFDM.