Smart antenna arrays for CDMA systems

There are a diverse range of products and services currently on the market, but cellular or personal communications services (PCS) radio networks probably have the highest public profile. These services provide highly mobile, widely accessible two-way voice and data communications links. In general, the most complex and expensive part of the radio path for these systems is the base station. As a result, manufacturers have been designing networks that have high efficiency in terms of the bandwidth occupied and the number of users per base station. Base station antenna arrays are a promising method for providing large capacity increases in cellular mobile radio systems. This article considers channel-modeling issues, receiver structures, and algorithms, and looks at the potential capacity gains that can be achieved. It considers antenna arrays for the mobile-to-base-station or reverse link of a CDMA cellular system. It begins with an introduction to CDMA communications systems and also addresses the general topic of antenna array receivers.