The comparison of various code assignment schemes in Wideband CDMA

This research compares the performance of static and dynamic OVSF code assignment schemes, in terms of call blocking probability and number of required call reassignment. In wideband code division multiple access (CDMA), in order to increasing system capacity, channelization codes are used to preserve the orthogonality between physical channels. The orthogonal variable spreading factor (OVSF) codes are used as the channelization codes in this system. The spectral efficiency of the system depends on the code assignment schemes. In addition, the maintenance of the orthogonality among the assigned OVSF codes causes the code blocking problem. Efficient channelization code management, result in high efficiency of code utilization and increasing system capacity.