Antenna Selection for MIMO Systems
MIMO systems have recently attracted tremendous interest due to their ability in providing great capacity improvements. However, the deployment of multiple antennas would require the implementation of multiple RF chains that are typically very expensive. Dealing with this issue,  firstly proposed to select only the most useful antennas for further signal processing, namely, only L out of N antennas are effectively deployed, and only L RF chains are thus required. Since then, antenna selection has been applied to MIMO links and various criteria for receive antenna selection or transmit antenna selection were proposed aiming at minimizing the symbol error rate or maximizing the capacity bounds. However, most of the present results are based on the uncorrelated channels and instantaneous channel state information (IC-SI) is assumed to be known at the transmitter.
In our work, we present the optimal antenna selection criterion for capacity maximization in correlated channels assuming that only the long-term channel statistics (LT-CS) are available . We show that our proposed selection algorithm, which we shall refer to as correlated selection algorithm (CSA) has the advantage of introducing great complexity reduction than that using IC-SI which we refer to as instantaneous selection algorithm (ISA) with very slight capacity degradation. Besides, a new low-complexity selection algorithm is proposed which consists of iteratively searching the local optimal antenna subset at each stage and can achieve very close performance to CSA while significantly reduce the complexity.
 M. Z. Win and J. H. Winters, "Analysis of hybrid selection/maximal-ratio combining in Rayleigh fading," IEEE Trans. Commun., Vol. 47, No. 12, p. 1773-1776, Dec. 1999.
 Lin Dai, Sana Sfar, and Khaled B. Letaief, "Optimal Antenna Selection Based on Capacity Maximization for MIMO Systems in Correlated Channels," IEEE Trans. Commun., vol. 54, no. 3, pp. 563-573, Mar. 2006.