Method for Reducing Peak-to-Average Power Ratio in OFDM Signals Using Companding Transform

This method utilizes companding transform to effectively reduce the peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) signals. Companding transform is a signal processing technique that modifies the time-frequency distribution characteristics of signals through transformation and reconstruction processes. In implementation, the approach involves applying a nonlinear compressing function to amplitude peaks followed by an expanding function at the receiver side, typically implemented using piecewise mathematical functions like μ-law or A-law companders. The key algorithm parameters (e.g., compression threshold and expansion ratio) can be dynamically adjusted through iterative optimization loops to achieve optimal PAPR reduction. This technique can be integrated into OFDM systems using digital signal processing blocks, where the companding operation is applied before inverse fast Fourier transform (IFFT) at the transmitter and after FFT at the receiver. The method significantly improves system performance and reliability by reducing signal distortion and enhancing power amplifier efficiency in wireless communication systems.