Wuhan Ligong Daxue Xuebao (Jiaotong Kexue Yu Gongcheng Ban)/Journal of Wuhan University of Technology (Transportation Science and Engineering)

Abstract : The growing need for the use of the internet and mobile services has increased the demand for the number of users for the mobile phone system without affecting the utilization of the available frequency spectrum. Specifically in urban areas, where the demand is higher. Code Division Multiple Access (CDMA) technology is considered the most efficient method for transmitting data across wireless networks, which enables the use of multiple users at the same time without increasing the frequency band. Based on the difference between the multi-stage multi- user CDMA and the standard multi-user CDMA, it was decided that there was a growing need to examine and compare the two systems. In this research, multi-stage multi-user CDMA is implemented and examined. In addition, the comparison between the standard multi-user CDMA technology and the multi-stage multi-user CDMA has been accrued between base stations and mobiles for the downlink. The efficiency of the system, the user number supported by the system, the bit error rate (BER), as well as the spreading factor, were the key parameters evaluated and examined. The two models are implemented utilizing MATLAB simulations. The results detected a tradeoff between the two models in terms of system efficiency and the number of users. Moreover, the multi-stage multi-user CDMA performs a significant improvement in spectral efficiency, interference reduction, user separation enhancement, and better BER. Therefore, based on the results, utilizing multi-stage multi-user CDMA technology introduces a significant advantage to the system.