Calculation of error probability of reception of the signal in the presence of multiple access interference

A new formula of bit error probability of reception of a signal in the presence of multiple access interference is calculated. A proposed solution is based on Chernoff approach with respect to Van Trees correction. It is demonstrated that the new formula obtained can achieve a good approximation of ideal formula and at the same time provides low complexity of calculation of bit error value. The proposed formula is created for environment of BPSK modulation in presence of multiple access interference and additive white Gaussian noise (AWGN), but can be extended for more complex Rayleigh fading case and higher order modulations. Moderate complexity of calculation method allows usage of this equation in different applications, where consistent calculation of error probability is required.