Partial Parallel Interference Cancellation Multiuser Detection In Wcdma System

In CDMA system, multiple access interference limits the capacity of any system using conventional single user correlation or matched filter receivers. Previous research has shown that multiuser detection receivers that employ interfernce cancellation techniques can significantly improve the capacity of a CDMA system.The focus of this dissertation is the study of advanced processing techniques for multiuser interference cancellation in direct sequence code division mutiple access communication. Emphasis is placed on the development of efficient techniques that are practical to implement. Then the effect of MUD on the radio network planning is also investgated.The work begins with a study of several sub-optimal multiuser detection techniques under a variety of conditions. Multistage parallel interference cancellation is identified as a practical and robust approach for mitigating multiple access interference. In order to reduce the effect of biased decision statistics inherent to parallel cancellation ,a low-complexity modification to parallel interference cancellation called partial parallel interference cancellation is derived, Which significantly improves performance. Then A PPIC MUD receiver based on the WCDMA system is designedAdditionally, the effect of MUD on the system's coverage and capacity is also investigated. The effect of MUD on the performence of system can be considered the MUD's efficience obtained by the link simulation, which depends on the algorithm of the MUD, and the system multiplexing factor which depends on all kinds of factors related to the radio propagation environment in the cell network system planning, for example the cell scale, channel model, the system load and the user distribution.