Optimum OVSF code reassignment in Wideband CDMA forward radio link

This paper focuses on minimizing the code reassignment cost in Wideband CDMA forward link. The channel allocation of wireless links can be transformed into the Orthogonal Variable Spreading Factor (OVSF) code assignment problem. Orthogonality constraint in the OVSF code tree may prevent efficient resource utilization. Code reassigning process can achieve an average of 20% gain of system throughput. Minimizing the code reassignments is essential in reducing the complexity of the wireless system. We present the design methodology and implementation techniques of the proposed efficient algorithm MIN in optimizing the reassignment cost. The simulation result indicates that the MIN algorithm can reduce in average 60% of the reassignment cost compared to that of the heuristic method and it is feasible for implementing in Base Station or Radio Network Controller.