Patent ID: 7408975
Filing Date: 2008-08-05
Classification: H04B,H04W

Abstract:
1. A method for transmit power adaptation in a CDMA wireless communication system receiving mobile station signals, said system including a plurality of K mobile stations communicating with at least one base station having a successive interference cancellation receiver, the method comprising: estimating channel gain for each mobile station, to thereby form a corresponding estimated channel gain, in response to received mobile station signals; ordering received signals from the mobile stations on a basis of the corresponding estimated channel gain from the mobile station associated with a highest channel gain G determining a transmit power S for x where x 1 =1 and P b is an average probability of a bit error and Λ i , is a signal-to-interference -plus-noise ratio associated with the i th strongest user, said minimizing comprising obtaining partial derivatives of P b with respect to each of the x i , i=2, . . . , K, setting the partial derivatives equal to zero, and solving the resulting set of simultaneous equations; and transmitting to each mobile station the determined transmit power associated with that mobile station.