Evaluating the performance of 2-D RAKE receivers with interference cancellation

In a spread-spectrum communication system, the capacity is limited by multiple access interference. It is well-known that with the use of an adaptive antenna and interference canceller, the performance of the system can be greatly improved. This paper investigates how the performance and complexity of the system are affected by the configurations of the adaptive antenna, the 2-D RAKE receiver and the interference canceller. By performing interference cancellation within the 2-D RAKE receiver, the output SINR of the system can be improved and computations needed in interference cancellation can be reduced. For the purpose of obtaining more accurate weights for the 2-D RAKE fingers, an FFT beamformer which is capable of forming M orthogonal antenna patterns are used. With the use of the FFT beamformer, less fingers are needed to achieve good overall performance. Hence, the structure of the 2-D RAKE receiver with interference cancellation can be simplified and is more implementable.