A Novel Receiver Based Technique for Monitoring Spectral Re-growth and Mitigating Adjacent-Channel Interference

We introduce a novel receiver based technique for estimating the spectral re-growth experienced by a modulated carrier transmitted through a power efficient nonlinear amplifier. Our approach builds upon the accurate characterization of the resulting nonlinear channel as a Volterra filter. The information contained in the filter coefficients is used to estimate the level of the principal side-lobes in the signal power-spectral density. Also, we demonstrate the ability of our proposed technique to provide accurate estimates using relatively short symbol sequences and its robustness to mismatch in amplifier characteristics. This makes our approach well suited for use in bandwidth and energy efficient satellite return links where adjacent carrier interference caused by spectral re-growth can severely impair performance.