Interference Cancellation in the Synchronous Downlink of CDMA-Systems

The concept but also a problem in CDMA is the interuser-interference, which limits the system capacity. Interference cancellation (IC) techniques promise an improvement, generally with a large expense in computation complexity. Thus, suboptimal but less complex methods are required. We consider the downlink and show that the computational complexity can be strongly reduced applying some restrictions on the signals like synchronity and orthogonal codes. Although our method is suboptimal, simulations show that in a given scenario consisting of a full-loaded cell in a 3-path-propagation environment, the degradation is only 1 dB against the optimum.