create awgn noise

Compute the system’s BER for SNR range of 0-15 dB with a step of 2 dB for PSK modulation and Plot BE

In digital transmission, the number of bit errors is the number of received bits of a data stream, over a communication channel that, have been altered due to noise, interference, distortion or bit synchronization errors.
The bit error rate or bit error ratio (BER) is the number of bit errors divided by the total number of transferred bits during a studied time interval. BER is a unit less performance measure, often expressed as a percentage.
SNR is actually the ratio of what is wanted (signal) to what is not wanted (noise). A high SNR means the signal is less corrupted by noise; a low SNR means the signal is more corrupted by noise.