Inter-Cell Interference Cancellation in CDMA Array Systems by Independent Component Analysis
Tapani Ristaniemi, K. Raju, Juha Karhunen, Erkki Oja · 2003
Abstract — The most important use of a spread spectrum com-munication system is that of interference mitigation. In fact, a spread spectrum communication system has an inherent temporal interference mitigation capability, usually called a processing gain. This gain enables the system to work properly in many cases. At times, however, the interference can be too strong, or the require-ments for the link quality are more stringent, so that additional interference mitigation is needed. In a cellular network the interference originating from the neighboring cells, called inter-cell interference, is one of the rea-sons for the need for additional interference mitigation capabil-ity in a receiver. In this paper we consider Independent Compo-nent Analysis (ICA) for the mitigation of inter-cell interference. Namely, we consider the use of ICA as an advanced pre-processing tool, which first mitigates the interference from the received array data and passes the residual signal for the conventional detection. Numerical experiments are given to evaluate the performance of two variants of the ICA-assisted receiver chains. They indicate clear performance gains in comparison to conventional detection without interference mitigation. In addition, the ICA-assisted re-ceiver chains are robust against the fluctuations in the loads of the cells, which is an important feature in practice. I.