Real-time smart antenna processing for GSM1800 base station

We successfully implemented a smart antenna array processor for a GSM1800 base station. The entire array processing run-time is only 1 ms, allowing real-time adaptation of the antenna pattern every GSM frame. The array processing is based on the estimation of the DOAs in the uplink. Separate DOA trackers for uplink and downlink, angular selection diversity, and beamforming with broad nulls guarantee robustness in mobile radio channels. Measurements in a LOS scenario show that the DOA estimation accuracy is on the order of 1° for 0 dB input SNR. BER measurements confirm the expected signal-to-noise gain of ≈9 dB compared to the single antenna case. In case of one interferer a BER of 1% is reached for an input C/I of -6.5 dB