Downlink Site Selection Transmit Diversity with Power Allocation for a 2-Dimensional Block Spread DS-CDMA Cellular System

摘要

2D block spread direct sequence-code division multiple access (DS-CDMA) allows multi-rate/multi-connection without causing downlink multi-access interference (MAI) in the presence of a frequency-selective fading channel. However, in a cellular system, the inter-cell interference remains. The site selection diversity transmission (SSDT) can be used to reduce the inter-cell interference and increase the downlink capacity. In this paper, we show that if adaptive power allocation is applied, where the BS allocates different power levels to different users according to their channel conditions, 2D block spread DS-CDMA with SSDT provides larger downlink capacity than the conventional DS-CDMA with SSDT.