System-Level Performance of Antenna Arrays in CDMA-Based Cellular Mobile Radio Systems

Abstract

<p/> <p>Smart antennas exploit the inherent spatial diversity of the mobile radio channel, provide an antenna gain, and also enable spatial interference suppression leading to reduced intracell as well as intercell interference. Especially, for the downlink of future CDMA-based mobile communications systems, transmit beamforming is seen as a well-promising smart antenna technique. The main objective of this paper is to study the performance of diverse antenna array topologies when applied for transmit beamforming in the downlink of CDMA-based networks. In this paper, we focus on uniform linear array (ULA) and uniform circular array (UCA) topologies. For the ULA, we consider three-sector base stations with one linear array per sector. While recent research on downlink beamforming is often restricted to one single cell, this study takes into account the important impact of intercell interference on the performance by evaluating complete networks. Especially, from the operator perspective, system capacity and system coverage are very essential parameters of a cellular system so that there is a clear necessity of intensive system level investigations. Apart from delivering assessments on the performance of the diverse antenna array topologies, in the paper also different antenna array parameters, such as element spacing and beamwidth of the sector antennas, are optimized. Although we focus on the network level, fast channel fluctuations are taken into account by including them analytically into the signal-to-interference calculation.</p

On the statistical description of the AoA of the uplink interfering signals in a cellular communication system

“…The half-power beamwidths of the BS antenna radiation patterns are 10, 65 and 120 • , respectively. The patterns are cosine-like with side lobe level SLL = −15 dB, (typical measured values for single cluster WCDMA networks [16,17]). Differences are observed at angles that point at the edges of the interfering cell.…”

Hexagonal vs Circular Cell Shape: A Comparative Analysis and Evaluation of the Two Popular Modeling Approximations

“…The BS antenna radiation patterns are cosine-like with side lobe level -15 dB and half-power beamwidth 10, 65, and 120 degrees, respectively (Czylwik & Dekorsy, 2004;Niemelä et al, 2005). Figure 8 depicts the probability that an interfering cell causes interference over φ in the network (in a single cluster system, this probability is even function).…”