[IEEE 2017 CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON) - Pucon (2017.10.18-2017.10.20)] 2017 CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON) - Analytical performance evaluation for M-QAM with cochannel interference in cellular networks over AWGN and Rayleigh fading channels