Write a simulation that implements an OQPSK transmitter. Place a bandpass filter on the transmitter output to limit the transmitted signal to the main lobe.
Create two adjacent channels, which are also OQPSK transmitters limited to the main lobe. Place the adjacent channels as close as possible to the desired channel, without allowing the spectra to overlap.
Pass the signals through an AWGN channel, and a matched filter receiver. If the interfering signals are not present, set the BER of the system to 10-3. Use MC simulation to estimate the BER when the interfering signals are equal in power to the desired signal.