Adaptive combination of cancelling co-channel interference and decoding of error-correcting codes for DS-SS CDMA mobile communication system

Abstract

This paper introduces an adaptive cascaded combination of cancelling co-channel interference (CCI) and decoding of error-correcting codes for a DS-SS CDMA mobile communication system. The analysis of a previous study by Shaheen and Gupta (see IEEE IPCCC Proceedings, Phoenix, Arizona, March 1995) indicated that conventional CCI cancellation techniques might not be as effective, especially for heavily loaded mobile communication systems. This paper extends this work by incorporating integrated filtering and decoding techniques. The extended system is evaluated under the same extreme interference conditions where the receiver is subjected to intersymbol interference (ISI), multi-access interference (MAI), and co-code CCI (CCCCI) generated within the mother cell and from the neighboring cells. Theoretical and simulation results are developed to evaluate the proposed system performance using signal to noise ratio (SNR) and bit error rate (BER) versus number of interfering users from within the cell and from the surrounding cells, and the normalized mean square error (MSE) in parameters estimation.