TY - GEN

T1 - Optimization of training and feedback for beamforming over a MIMO channel

AU - Santipach, Wiroonsak

AU - Honig, Michael L.

PY - 2007

Y1 - 2007

N2 - We examine the capacity of beamforming over a block Rayleigh fading Multi-Input/Multi-Output (MIMO) channel with finite training for channel estimation and limited feedback. A fixed-length packet is assumed, which is spanned by T training symbols, B feedback bits, and the data symbols. The training symbols are used to obtain a Minimum Mean Squared Error (MMSE) estimate of the channel matrix. Given this estimate, the receiver selects a transmit beamforming vector from a codebook containing 2B i.i.d. random vectors, and relays the corresponding B-bit index back to the transmitter. We derive bounds on the large system capacity, i.e., as the number of transmit antennas Nt → ∞ and receive antennas Nr → ∞ with fixed ratio Nt/Nr. The bounds are used to show that the optimal T, which maximizes the capacity, increases as N t/ log Nt, whereas the optimal B increases as N t/ log2 Nt.

AB - We examine the capacity of beamforming over a block Rayleigh fading Multi-Input/Multi-Output (MIMO) channel with finite training for channel estimation and limited feedback. A fixed-length packet is assumed, which is spanned by T training symbols, B feedback bits, and the data symbols. The training symbols are used to obtain a Minimum Mean Squared Error (MMSE) estimate of the channel matrix. Given this estimate, the receiver selects a transmit beamforming vector from a codebook containing 2B i.i.d. random vectors, and relays the corresponding B-bit index back to the transmitter. We derive bounds on the large system capacity, i.e., as the number of transmit antennas Nt → ∞ and receive antennas Nr → ∞ with fixed ratio Nt/Nr. The bounds are used to show that the optimal T, which maximizes the capacity, increases as N t/ log Nt, whereas the optimal B increases as N t/ log2 Nt.

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U2 - 10.1109/WCNC.2007.216

DO - 10.1109/WCNC.2007.216

M3 - Conference contribution

AN - SCOPUS:36348964109

SN - 1424406595

SN - 9781424406593

T3 - IEEE Wireless Communications and Networking Conference, WCNC

SP - 1140

EP - 1144

BT - 2007 IEEE Wireless Communications and Networking Conference, WCNC 2007

T2 - 2007 IEEE Wireless Communications and Networking Conference, WCNC 2007

Y2 - 11 March 2007 through 15 March 2007

ER -