Code-hopping multiple access (CHMA) has been an emerging multiple access technology designed to increase the number of users in Code-division multiple access (CDMA) systems. It was designed to overcome the limitations in the number of code word's required for communication in existing systems. However, it may experience degradation due to symbol perforation occurring due to code collisions when the code symbols are different, resulting in increase in error in detection. In this paper we address CHMA in Rayleigh flat fading channels using different spreading sequences. Receiver diversity techniques such as MRC are discussed to improve the performance of received signals under Interference and noise for existing CHMA systems. Performance measures like bit error rate are plotted for the transmitted data model for CHMA system under Rayleigh flat fading channel under various system parameters.