European Smart antenna test-beds

Spatial Channel Characterization for Smart Antenna Solutions in FDD Wireless Networks

“…Smart, or adaptive antennas offer a complementary solution to enhancing spectrum efficiency by exploiting the spatial, or both the spatial and temporal domains of the signalling space [2]. Numerous researchers have reported capacity enhancements of between 200% to 300% from both theoretical and field trial based evaluations [3], [4] thus demonstrating the benefits of this technology to network operators and equipment manufacturers alike.…”

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

“…A similar technique called grid of beams (GOB) can be used with digital beamforming systems, which selects the appropriate weight vector from a stored set. This, however, leads to a more complex implementation due to the drawbacks associated with digital beamforming that are highlighted in [13] and [14]. GOB does not require the beams to be orthogonal, enabling the beam cusp to be adjusted and an arbitrary number of beams can be formed, each of 3-dB beamwidth dB , given by dB (1) (assuming uniform array amplitude weighting) [15].…”

“…Furthermore, applying a window function such as a Hanning or Hamming window can control the sidelobe levels. A GOB beamformer was implemented in the TSUNAMI II field trials system, which used 11 beams distributed over a 120 sector [13]. 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.…”

“…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.…”

“…The field trials reported in [19] showed a 3-dB improvement in the downlink carrier-to-interference ratio for a similar system. Furthermore, a GOB system was implemented in the TSUNAMI II field-trials system [13]. A mean received power gain of 14.7 dB above a single element system was recorded for this configuration.…”