Comparison of Bit Error Rate And Performance Analysis For Multicode CDMA Techniques in Fading and AWGN Channels
Hayder Fadhil Abdulsada, Samir Jasim Mohammed · 2022 5th International Conference on Engineering Technology and its Applications (IICETA) · 2022
In recent years, wireless communication technology has made great progress. With the rapid growth of video, voice, and data communications, mobile phones have become ubiquitous and so need mobile multimedia communications. To meet the increasing demands of mobile communication services, many solutions have been proposed to reduce the impact of channel effects and increase the speed of data transmission. One of those methods is the use of Multicode Code Division Multiple Access (MTC -CDMA). Two techniques of the MTC-CDMA system have been used, which are multicode system and orthogonal code system. The MTC-CDMA system can support different data rates as needed by next-generation standards. The bit error rate (BER) of the two systems is analyzed in AWGN and Rayleigh fading channels. The multicode system has been simulated with different codes for both code sequence sets and user-specific sequences. These codes are Walsh-Hadamard, orthogonal variable spreading factor (OVSF), Gold, Kasami, and Maximum length sequence (M-sequences) codes. The orthogonal code system is simulated with Walsh-Hadamard spreading code. The results show that the use of Walsh-Hadamard code as user specific sequence and the Gold code as a code sequence gives better BER performance compared with other types of codes for the multicode system. Also, the using of Walsh-Hadamard for sequence sets and PN codes for user specific sequences gives good performance. For the same M-ary, the number of users, and spreading code length, the orthogonal code system can achieve better BER performance than the multicode system, but the maximum number of users that can be accessed is less.