BER and PAPR Reduction Using Companding Algorithms in OFDM

Orthogonal Frequency Division Multiplexing is an attractive technology for wireless communication. It offers high spectral efficiency, power efficiency and multipath delay tolerance. The nonlinear characteristics of high power amplifiers are very sensitive to signal amplitudes. OFDM is a multicarrier scheme in which number of carriers is added coherently, when they added together it increases average power of signal amplitudes. High average power leads to distortion in operation of system. This effect is known as peak to average power ratio (PAPR) is a major drawback of orthogonal frequency division multiplexing (OFDM) systems. In literature many techniques were developed to reduce Bit error rate and PAPR. Among the various PAPR reduction techniques, companding transform appears attractive for its simplicity and effectiveness. In this paper, evaluation of performance of companding algorithms µ-law companding, Exponential companding, companding Airy function is compared in terms of bit error rate and peak to average power ratio.