This program simulates the bit error rate (BER) performance of BPSK modulation in an Additive White Gaussian Noise (AWGN) channel. The simulation is performed at baseband so there is no need of a carrier and sampling rate of 1 sample/symbol or 1 sample/bit is used. The simulation is done using real numbers since we do not need to model two orthogonal carriers as we would need to do for QPSK modulation.