DigiComm: A MATLAB-based digital communication system simulator [Testing ourselves]

A simple digital communication virtual tool, DigiComm, is introduced. This tool visualizes the transmission of binary data in different channels using frequency-shift keying (FSK) and accessing the shared media via frequency-division multiple access (FDMA). The transmitter part generates binary data, and modulates the frequencies of both carriers of each channel. The signals of each channel with noise added are distinguished from each other using bandpass filters (BPF) at the receiver, and converted to binary data by counting the zero crossings at the receiver part. Signals at the transmitter and receiver can be displayed in the time or frequency domains. Bit-error rates (BER) are calculated for a given signal-to-noise ratio (SNR) by comparing the received bits with the transmitted bits.