This paper presents a performance analysis of wireless networks using error correcting codes on channels with Rayleigh fading in the presence of co-channel interference. The performance is evaluated in terms of the average bit error rate (BER) using TCM (Trellis-Coded Modulation) and TTCM (Turbo Trellis-Coded Modulation) schemes for QAM modulations. The effects of co-channel interference are evaluated through Monte Carlo simulation in scenarios where the system is affected by a dominant interfering synchronous and similar to the target user. For each coded-modulation schemes, the results show that there are BER floors, which vary according to the signal-interference (S/I). © 2012 IEEE. Lopes, W., Queiroz, W., Madeiro, F., Alencar, M., Exact Bit Error Probability of M-QAM Modulation Over Flat Rayleigh Fading Channels (2007) Microwave and Optoelectronics Conference, 2007. IMOC 2007. SBMO/IEEE MTT-S International, pp. 804-806. , vol., no., OctNg, S.X., Liew, T.H., Yang, L.L., Hanzo, L., Comparative Study of TCM, TTCM, BICM and BICM-ID schemes (2001) IEEE Vehicular Technology Conference, p. 265. , (CDROM), MayTralli, V., Verdone, R., Performance Characterization of Digital Transmission Systems with Cochannel Interference (1999) IEEE Trans. Veh. Technol., 48, pp. 733-745. , MayAltamirano, D., De Almeida, C., Evaluation of the Effects of the Co-Channel Interference on the Bit Error Rate of Cellular Systems for BPSK Modulation (2010) IEEE/SBrT International Telecommunications Symposium ITS 2010, pp. 1-6. , SepQuelal, G., Moya, D., Benítez, E., Altamirano, D., De Almeida, C., Evaluation of the Effects of Co-Channel Interference on the Bit Error Rate for QPSK and M-QAM Modulations (2010) IEEE/SBrT International Telecommunications Symposium ITS 2010, pp. 1-6. , SepDu, Z., Cheng, J., Beaulieu, N., BER Analysis of BPSK Signals in Ricean-Faded Co-Channel Interference (2007) IEEE Transactions on Communications, 55 (10). , OctLiu, X., Hanzo, L., Exact BER of rectangular-constellation QAM subjected to asynchronous co-channel interference and Nakagami-m fading (2006) Electronics Letters, 42 (15), pp. 868-869. , DOI 10.1049/el:20060974Altamirano, D., De Almeida, C., Evaluation of the Effects of Co-Channel Interference on the Bit Error Rate of Coded Cellular Networks (2011) Proceedings of the International Workshop of Telecommunications IWT 2011, pp. 161-163. , MayAltamirano, D., De Almeida, C., Evaluation of the Co-Channel Interference Effects on the Performance of Coded Networks (2011) Communications (LATINCOM), 2011 IEEE Latin-American Conference on, pp. 1-4. , vol., no., 24-26 OctDivsalar, D., Simon, M.K., The Design of Trellis Coded MPSK for Fading Channel: Performance Criteria (1988) IEEE Transactions on Communications, 36, pp. 1004-1012. , SepRobertson, P., Worz, T., Bandwidth-efficient turbo trellis-coded modulation using punctured component codes (1998) IEEE Journal on Selected Areas in Communications, 16 (2), pp. 206-218. , PII S0733871698002297