The Evaluation and Performance Analysis for Soft Handoff in DMA Cellular Systems

The paper presents the analysis of integrated voice/data slotted code division multiple access (CDMA) system with soft handoff. Some important characteristics of the cellular configuration in soft handoff systems are used to propose a new design of an efficient call admission control (CAC) in CDMA systems. In particular, voice communications and data transmissions are considered. Voice terminals have a higher priority over the data terminals in accessing the shared channel. This paper is denoted a continuous-time Markov chain (CTMC) model for CAC in CDMA with a soft handoff queue and obtains a closed form solutions. In addition, using subrating scheme a reserved channel is splitted into two half rated channels to accommodate more voice handoff calls. The balking and reneging behavior of the handoff voice calls is also incorporated. In order to determine handoff traffic arrival rate, an iteration algorithm is developed. The expressions for the blocking probability of the new calls, blocking probability of the handoff data/voice calls are computed analytically as well as by soft computing technique viz. adaptive network based fuzzy inference system (ANFIS). Numerical results show the effectiveness of the proposed Markov chain model and the benefits of the soft handoff scheme. Our results give good approximation as demonstrated by giving a numerical illustration.