Low-complexity companding function design for PAPR reduction in OFDM systems

In this study, the authors have proposed a low complexity companding function for peak-to-average-power ratio (PAPR) reduction in orthogonal frequency division multiplexing systems. This function transforms the signals into a probability density function with a cumulative distribution function an anti-trigonometric function. By carefully choosing the transform parameters, the bit error rate (BER) performance can be improved significantly during the reduction of PAPR. In addition, the proposed companding function offers design flexibility. Simulation results show that for the same PAPR performance, the proposed companding scheme can offer better BER performance. For example, upon assigning BER = 10(-4)in an additive white Gaussian noise channel without a solid-state power amplifier, the minimum required bit energy to noise power spectral ratio (E-b/N-o) for the proposed companding scheme withc = 0 andA = 1.414 is 11 dB. It is 5, 4.2, and 3 dB lower than exponential companding function, root-based mu-law companding function, and amplitude limiting companding schemes, respectively. Also, their PAPR performance is the same.