Call elapsed time and reduction in code blocking for WCDMA networks

Traditional Orthogonal Variable Spreading Factor (OVSF) code assignment designs aim to reduce code blocking irrespective to the complexity and cost involved. We propose an OVSF code assignment scheme which reduces the complexity involved as compared to crowded first assignment scheme (which is one of the most popular single code assignment schemes). This is because the proposed scheme needs to check the immediate parent of the vacant code for code assignment. The crowded first scheme on the other hand checks all the ancestors of the vacant codes up to the root of the code tree. The code blocking performance can be inferior to the CFA design but the number of code searches (which decides the speed of the assignment design) is reduced considerably. Simulation results are demonstrated to show the superiority of the proposed design.