Reverse Link Capacity of CDMA Systems with Imperfect Beamforming Using Different Types of Antenna Arrays

Abstract

The reverse link capacity of a direct-sequence code-division multiple-access (DS-CDMA) system in a multicell environment with both perfect and imperfect beamforming has been studied recently. In a practical implementation, the design of the antenna array may be constrained by the available space or the number of antennas. We investigate the maximum reverse link capacity of CDMA systems using different types of arrays, including linear, circular and rectangular arrays, with a fixed size. The CDMA capacity for different types of arrays with a fixed number of antennas is also examined. The capability of antenna arrays to combat the impairments of beamforming, such as arrival angle estimation errors and angular spreads, is closely related to their geometries. The impact of array geometry on system performance considering beamforming impairments is also examined and illustrated through numerical results.