SIR estimation in CDMA cellular systems using subspace tracking

Several radio resource management algorithms such as power control and handoff use the signal-to-interference ratio (SIR) as a control parameter. We address the problem on how to obtain fast and accurate measurements of this quantity in the context of a time varying channel. We develop, a subspace based SIR tracking algorithm for CDMA cellular systems. Analysis and simulation results for an IS-95 like system show that the SIR can be estimated to within 80 percent of the actual SIR after less than 7 frames, or within 90 percent of the actual SIR after less than 15 frames.