Neighbour code capacity and reduction in number of code searches

Orthogonal Variable Spreading Factor (OVSF) based networks require careful assignment of code to a new call. In this paper an assignment design is proposed which reduces number of code searches with less code blocking probability. The proposed design partitioned code tree into two parts and for a new call the algorithm needs to check one portion of the code tree for most of the calls. If no vacant code is available in that portion then second portion is checked. Also, it starts code search from bottom to top along the tree both these factors leads to less number of code searches before assignment. Further, code blocking is reduced as it jumps to that portion of code tree where a vacant code is available, blocking almost those codes blocked by previous calls. Simulation results shows improvement in terms of code blocking probability and number of code searches.