Non-linear spectral analysis of direct conversion wireless receivers

Abstract

We exploit spectral analysis to investigate the impact of non-linearities on the performance of wireless receivers, with particular reference to the direct conversion architecture. Actual interferer spectra and interferer magnitude fluctuations are methodically taken into account by modeling signals as Gaussian stochastic processes. Input-referred second-order and third-order intermodulation powers are found to be, respectively, 7.8 dB and 1.25 dB higher than predicted by the classic sinusoidal analysis. Time domain simulations carried out using the Universal Mobile Telecommunications System (UMTS) standard as test vehicle show excellent agreement with the developed analysis, which proves to be capable of accurate bit error rate (BER) predictions.