Combined power and rate adaptions in DS/CDMA Communications over fading channels
Ye Hoon Lee, Sun Yong Kim · 2007
We propose a combined power and rate adaptation scheme in direct-sequence code division multiple access (DS/CDMA) communications over Nakagami fading channels. The transmission power proportional to Gipis allocated to the data transmission of user i, where Giis the channel gain for user i, and p is a real number, and the data rate (i.e. spreading gain) is jointly adapted so that a desired transmission quality is maintained. We analyze the average data rate of the proposed adaptation scheme subject to fixed average and peak transmission power constraints. Our results show that the proposed joint adaptation scheme has considerable performance improvements over power only adaptation and rate only adaptation for a range of system parameters.