Field trial with a GSM/DCS1800 smart antenna base station

We present measurement results with a GSM1800 smart antenna base station. The base station is equipped with an adaptive antenna array processor that allows in every GSM frame full beam adaptation in uplink and downlink. The smart antenna processing is based on the estimation of the directions of arrival in uplink. It includes separate DOA trackers for uplink and downlink, angular diversity, and beamforming with broad nulls. Measurements in a static line-of-sight (LOS) scenario demonstrate the potential to suppress interference by 25 dB. The smart antenna achieves a bit-error ratio (BER) of 1% at a carrier-to-interference ratio of -14 dB. A field measurement in a microcell setup confirms the tracking capability even in scenarios with strong multipath. In a non-LOS situation we achieve an average signal-to-noise gain of 7.4 dB, while it increases up to 8.3 dB in a LOS environment. The angular diversity concept results in an additional diversity gain of 5.8 dB at the 1% BER level in the case of NLOS when a dual beam configuration is applied