Co-Channel Interference Reduction on the Forward Channel of a Wideband CDMA Cellular System

Wtdeband code -dzvzsion multiple access (CD MA) systems are interference-limzted, and so must utilize some form of interference reductzon in order to maintain an acceptable qualtty of service and capacity. In this paper, cochannel interference for several different CDMA architectures is evaluated. For wideband CDMA systems such as WCDMA and cdma2000 with carrier st ealing, co-channel ~nterference is stgntjicantly reduced by the implementation of ezther mtcrozonmg or sectortng. The disadvantage of microzonzng M that mtra-cell interference is no longer idea[ly zero on the forward channel, as it is with sectoring and omntdtrectzonal architectures. For wideband CDMA systems such as cdma2000 without carrter stealing, co-channel interference M reduced by both mzcrozonzng and sectortng architectures even more than in the case of W-CDMA and cdma2000 with carrier stealtng. In this case, since forward channel intra-cell mierference remains ideally zero, the szgntficant reductton of co-channel interference by micro zon mg makes micro zoning clearly superzor to omnidirectional architectures.