Implementation of an Efficient Channelization Code Assignment Algor ithm in 3G WCDMA

Abstract

Channelization codes are valuable and scarce resources in 3G WCDMA. The objective of channelization code assignment is to support as many users as possible with less complexity. Some code assignment algorithms have been proposed. Most of the algorithms suffer from code-set fragmentation problem. To resolve this issue, code exchange and reassignment policies can be applied, but the system complexity will be increased. In this paper, we propose an efficient BLRU (Best-fit Least Recently Used) code assignment algorithm with less fragmentation and complexity to approximate the reassignment based optimal solution. Simulation results compare the blocking probability among three approaches. Considering both the system complexity and the blocking probability, the BLRU algorithm is a good candidate for channelization code assignment in 3G WCDMA.