A uniform random number generator is used to generate the binary information sequence from the binary data source. The sequence of ‘0’s and ‘1’s is mapped into sequence of +E and –E
where E represents the signal energy. E may be normalized to unity
The Gaussian noise generator is used to generate the sequence of ‘0’ mean and variance σ2 Gaussian random numbers. The detector compares the random variable ‘r’ with the threshold of ‘0’. If r > 0, the decision is made that the transmitted bit is ‘0’. If r < 0, the decision is made that the transmitted bit is ‘1’. The output of the detector is compared with the transmitted sequence of information bits and the bit errors are counted.