Statistical characterization of intermodulation products in a multicarrier LPA design

An approximation is developed by rigorous analysis and simulation for the probability density function of the amplitude of multicarrier intermodulation (IM) at any frequency of interest in an RF linear amplifier. The derived characterizing statistic of the distribution is a function of the carrier frequencies. The analysis shows that the IM product level generated by a nonlinear amplifier can be accurately modeled by a bivariate Gaussian distribution function. Thus, the amplitude of the IM products can in turn be statistically characterized by a Rayleigh distribution. Therefore, cochannel interfering IM products in a communication system can be modeled simply, by knowing the transmitted carrier frequencies, the associated average transmitted carrier signal power, and the desired received carrier frequency