In the paper the impact of impulsive noise on the symbol error probabilities (SEPs) of 8- and 16-ary CPSK transmissions is analysed. The transmission medium considered is a two-link nonlinear channel. The SEPs are evaluated in terms of up and down link carrier-to-noise ratios (CNRs), impulsive index of the noise (A), and the power ratio of the Gaussian noise-to-impulsive noise (π′). The bandpass nonlinearity (BPNL) considered exhibits both AM/AM and AM/PM conversions. A phase compensating receiver is assumed to compensate AM/PM conversion.