Optimal Receive Antenna Selection in Time-Varying Fading Channels with Practical Training Constraints

Kristem, Vinod and Mehta, Neelesh B and Molisch, Andreas F (2010) Optimal Receive Antenna Selection in Time-Varying Fading Channels with Practical Training Constraints. In: IEEE Transactions on Communications, 58 (7). pp. 2023-2034.

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Abstract

Hardware constraints, which motivate receive antenna selection, also require that various antenna elements at the receiver be sounded sequentially to obtain estimates required for selecting the `best' antenna and for coherently demodulating data thereafter. Consequently, the channel state information at different antennas is outdated by different amounts and corrupted by noise. We show that, for this reason, simply selecting the antenna with the highest estimated channel gain is not optimum. Rather, a preferable strategy is to linearly weight the channel estimates of different antennas differently, depending on the training scheme. We derive closed-form expressions for the symbol error probability (SEP) of AS for MPSK and MQAM in time-varying Rayleigh fading channels for arbitrary selection weights, and validate them with simulations. We then characterize explicitly the optimal selection weights that minimize the SEP. We also consider packet reception, in which multiple symbols of a packet are received by the same antenna. New suboptimal, but computationally efficient weighted selection schemes are proposed for reducing the packet error rate. The benefits of weighted selection are also demonstrated using a practical channel code used in third generation cellular systems. Our results show that optimal weighted selection yields a significant performance gain over conventional unweighted selection.

Item Type:	Journal Article
Publication:	IEEE Transactions on Communications
Publisher:	IEEE
Additional Information:	Copyright 2010 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.
Keywords:	Antenna selection; multiple antennas; diversity; methods; fading channels; channel estimation; modulation schemes; channel coding; delays; training
Department/Centre:	Division of Electrical Sciences > Electrical Communication Engineering
Date Deposited:	19 Oct 2010 07:22
Last Modified:	19 Oct 2010 07:22
URI:	http://eprints.iisc.ac.in/id/eprint/33144

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