PAPR reduction using precoding and companding techniques for OFDM systems

For multipath propagation systems OFDM provides good choice but also suffers with high peak to average power ratio (PAPR) at the transmitter side. High PAPR values results in non-linearites at transmission leading to complex designing. Therefore reduction of PAPR is necessary for lesser complexities, higher efficiency and greater stability. In this paper various PAPR reduction techniques have been developed. Different precoding matrices are used for PAPR reduction. Comparative analysis of μ-law companding and A-law companding techniques are also carried out to see the effect on PAPR values. Further studies are done by using various modulation techniques and varying no of subcarriers. Efficient reduction in PAPR values are obtained for applied techniques.