A method for estimating the average packet error rates of multi-carrier systems with interference

We propose a method for estimating the average packet error rates (PER) of a coded orthogonal frequency division multiplexed (OFDM) system when the signal is subject to interference with a shaped spectral density. Thus the interference has a different impact on each sub-carrier. Typically, the PER is a function of the received signal-to-noise-ratio (SNR) and the packet bits are distributed evenly amongst a fixed number of sub-carriers where each sub-carrier has the same SNR. The OFDM system under consideration here utilizes convolutional coding for error correction and Mn-ary square quadrature amplitude modulation (M-QAM) for signaling. The proposed method assumes that each sub-carrier is affected by a different interference power. The novelty in the analysis lies in equating the average interference power affecting each sub-carrier to an equivalent additive white Gaussian noise (AWGN) power. We compare PER prediction using this approach to simulation for a number of modulation and coding schemes (MCS) to validate that the proposed approximation can be used to calculate the average PER.