Exact BER analyses of Nakagami/Nakagami CCI BPSK and Nakagami/Rayleigh CCI QPSK systems in slow fading

A recent letter presented an approximate bit error rate (BER) analysis of coherent binary phase-shift keying (BPSK) in cochannel interference with Nakagami faded desired and interfering signals. Here, the exact BER of coherent nonreturn-to-zero (NRZ) BPSK with cochannel interference in Nakagami fading is derived showing that the approximate analysis may be inaccurate. The exact BER of NRZ quaternary PSK (QPSK) with Nakagami faded desired user signal and Rayleigh faded interfering signals is also derived. Slow fading, asynchronous timing and independent fading gains are assumed.