Allocation of Walsh codes and quasi-orthogonal functions in cdma2000 forward link

In this paper, we investigate the code allocation problem of forward link channelization, i.e., allocation of Walsh codes and quasi-orthogonal functions (QOF's) in cdma2000 systems. Given multipath power profiles, geometry factors, and allocated codes of mobile stations (MSs), we propose a simple solution for the total sector transmit power. It is shown that the sector transmit power can be expressed in terms of a single variable, namely, the lumped geometry factor (LGF), which accounts for MS geometry factors, code channel activities, and cross-correlations among all the allocated codes. The formula is used to devise a code allocation algorithm that is proven optimum in the sense of maximizing capacity, under the condition of single-path channels.