Reduction of peak-to-average power ratio of OFDM system using a compandingtechnique

A companding technique is proposed to reduce the peak-to-average-power rati o of orthogonal frequency division multiplexing (OFDM) signal in this paper . The probability density function of the amplitude of OPDM signal is deter mined. Because of the Gaussian distribution of OFDM signal, companding tech nique can be quite effective, since large OFDM signal only occurs infrequen tly. The peak-to-average power ratio of an OFDM system and the optimal comp anding coefficient are determined in this paper. Symbol error rate of the s ystems after the companding is derived. The performances of the system with and without the companding are also compared.