Downlink beamforming with delayed channel estimates under total power, element power and equivalent isotropic radiated power (EIRP) constraints

(2001). Downlink beamforming with delayed channel estimates under total power, element power and equivalent isotropic radiated power (EIRP) constraints. General rights This document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: Explore Bristol Research is a digital archive and the intention is that deposited content should not be removed. However, if you believe that this version of the work breaches copyright law please contact [email protected] and include the following information in your message: • Your contact details • Bibliographic details for the item, including a URL • An outline of the nature of the complaint On receipt of your message the Open Access Team will immediately investigate your claim, make an initial judgement of the validity of the claim and, where appropriate, withdraw the item in question from public view. Abstruct-A WLAN-type scenario where a base-station (access point) equipped with multiple antennas is transmitting and a mobile with only a single antenna is receiving, is considered. Three approaches are investigated: Grid-of-beams (GOB), Maximal-Ratio (MR) and equal-gain (EG), each with one of the following constraints 1) Total transmit power over all antenna elements, 2) Maximum power on any antenna element 3) Equivalent isotropic radiated power (EIRP). The median diversity gain for the MR approach was estimated to be 14.8dB, 10.6dB, and llAdB using constraint 1-3, respectively at 5.2GHz in a modem University building at 5-50 meter range. For GOB corresponding numbers are 9.4dB,9.4dB,2.3dB and for EG 13.9dB,13.9dB,10.3dB, respectively. These results were virtually independent of delay between channel estimation and use of the same estimate, when the delay is less than 130ms. This result was obtained although there were people moving in the environment. The diversity gain under the EIRP constraint is encouraging and shows that coverage improvements are possible even under EIRP limitations.