Improving the capacity and the quality of service of a DS-CDMA cellular system with integrated services
| dc.contributor.author | Zou, Jialin | |
| dc.contributor.supervisor | Bhargava, Vijay K. | |
| dc.date.accessioned | 2018-06-15T19:11:57Z | |
| dc.date.available | 2018-06-15T19:11:57Z | |
| dc.date.copyright | 1995 | en_US |
| dc.date.issued | 2018-06-15 | |
| dc.degree.department | Department of Electrical and Computer Engineering | en_US |
| dc.degree.level | Doctor of Philosophy Ph.D. | en_US |
| dc.description.abstract | In the design of the third generation of multi-media wireless networks, we are primarily concerned with the greatly varying information source rates, the quality requirements of various traffic types, the characteristics of the wireless environment, as well as the complexity and cost. Code Division Multiple Access (CDMA) cellular system is one of the most important candidates for supporting the future universal communications services. The objective of this research is to improve the capacity and the quality of service (QOS), as well as to reduce the complexity of cellular CDMA with integrated services, through improving or optimizing the design of system level operations. To facilitate the system performance and capacity evaluation, the multi-cell multi-user interference is analyzed through a new approach. The area averaged probability density function (PDF) of interference power from one active user is evaluated. The Gamma distribution is proposed for modelling the area averaged PDF of the interference power. An efficient method for evaluating system performance is developed. Differing from the Gaussian approximation, this method is very effective and accurate for both a large number and a small number of users. In this research, differing from the distance membership determination, the statistical effect of handoff is considered. The effects of soft handoff operation on multi-cell multi-user interference are analyzed. Membership statistics which are determined by soft handoff are investigated. A simple binomial model is proposed for modelling the distribution of the number of users belonging to a base station. Considering the call arrival statistics, user membership statistics and a finite number of channels available at a base station, we evaluate the call blocking/dropping rate. The minimum number of channels required at a base-station, which ensures a specified quality of service at a given capacity requirement, is determined. System capacity is further evaluated considering both outage probability limited by interference and call blocking/dropping rate limited by finite number of channels. A pilot assisted channel allocation method is proposed to minimize the number of channels required at a base station. Based on the analysis of a CDMA cellular system with a single traffic type, the design issues in developing a multi-media wireless networks are further discussed. The capacity of a CDMA cellular system with high quality requirements and mixed stream and packet types of traffic is assessed. The impact of the choice of a line rate (bit transmission rate through channel) on the system capacity is investigated. It is also shown that the power allocated to different types of traffic can be optimized to achieve maximum capacity. The optimum power allocation suggests that the power assignments to different traffic types are mainly determined by their quality requirements. | en_US |
| dc.description.scholarlevel | Graduate | en_US |
| dc.identifier.uri | http://hdl.handle.net/1828/9457 | |
| dc.language | English | eng |
| dc.language.iso | en | en_US |
| dc.rights | Available to the World Wide Web | en_US |
| dc.subject | Code division multiple access | en_US |
| dc.subject | Personal communication service systems | en_US |
| dc.subject | Wireless communication systems | en_US |
| dc.subject | Integrated services digital networks | en_US |
| dc.title | Improving the capacity and the quality of service of a DS-CDMA cellular system with integrated services | en_US |
| dc.type | Thesis | en_US |