Performance of switched beam systems in cellular base stations

On the Analysis of Switched-Beam Antennas for the W-CDMA Downlink

“…The results obtained in the reference show that this technique was unsuitable in interference-limited systems as the unwanted and wanted signal sources could not be identified when beams are selected on a best receiver signal-strength indicator (RSSI) basis. However, an extension to this technique reported in [13], [16], and [17] overcomes this by using training sequences or user color codes to distinguish between users. In [17], a carrier-to-interference ratio (CIR) improvement of between 1 and 4 dB using a four-beam system is reported, with the best improvement occurring at high received signal-to-noise-plus-interference ratios.…”

“…However, an extension to this technique reported in [13], [16], and [17] overcomes this by using training sequences or user color codes to distinguish between users. In [17], a carrier-to-interference ratio (CIR) improvement of between 1 and 4 dB using a four-beam system is reported, with the best improvement occurring at high received signal-to-noise-plus-interference ratios. Switched-beam systems implemented using a Butler matrix or radio-frequency (RF) beamforming network also have the advantage of being able to be a direct replacement for existing diversity systems.…”