TY - GEN
T1 - A dual-hop amplify-and-forward MIMO cooperative beamformer in distributed wireless sensor networks
AU - Baradaran, Hassan Aghaei
AU - Zarifi, Keyvan
AU - Affes, Sofiène
AU - Ghrayeb, Ali
PY - 2010
Y1 - 2010
N2 - In this paper, we propose a cooperative beamforming (CB) technique for dual-hop amplify-and-forward communication in WSNs with one source, N - 1 interferences, and K relay nodes. First, an optimal beamformer is obtained that maximizes the signal-to-interference-plus-noise ratio at the intended receiver in the far-field subject to the following constraints: 1) The relay nodes total transmit power is bounded; and 2) the received power from the N transmitters at L - 1 unintended receivers in the far-field is zero. It is shown that the optimal beamformer can only be implemented if each relay node knows the locations and the backward channels of all other relay nodes in the network. As this knowledge is not typically available at nodes in WSNs, we use a technique to approximate the optimal beamforming coefficients with quantities that depend only on the locallyavailable information at each individual relay node. The average beampattern expression of the proposed CB technique is then derived and its properties are analyzed. In particular, it is shown that the average gain of the beamformer linearly increases with K in the direction of the intended receiver while remaining fixed in the directions of the unintended receivers.
AB - In this paper, we propose a cooperative beamforming (CB) technique for dual-hop amplify-and-forward communication in WSNs with one source, N - 1 interferences, and K relay nodes. First, an optimal beamformer is obtained that maximizes the signal-to-interference-plus-noise ratio at the intended receiver in the far-field subject to the following constraints: 1) The relay nodes total transmit power is bounded; and 2) the received power from the N transmitters at L - 1 unintended receivers in the far-field is zero. It is shown that the optimal beamformer can only be implemented if each relay node knows the locations and the backward channels of all other relay nodes in the network. As this knowledge is not typically available at nodes in WSNs, we use a technique to approximate the optimal beamforming coefficients with quantities that depend only on the locallyavailable information at each individual relay node. The average beampattern expression of the proposed CB technique is then derived and its properties are analyzed. In particular, it is shown that the average gain of the beamformer linearly increases with K in the direction of the intended receiver while remaining fixed in the directions of the unintended receivers.
KW - Amplify-and-forward relaying
KW - Beampattern
KW - Cooperative beamforming
KW - Multiple-input multiple-output communication
KW - Wireless sensor networks
UR - http://www.scopus.com/inward/record.url?scp=79551616173&partnerID=8YFLogxK
U2 - 10.1109/GLOCOM.2010.5684083
DO - 10.1109/GLOCOM.2010.5684083
M3 - Conference contribution
AN - SCOPUS:79551616173
SN - 9781424456383
T3 - GLOBECOM - IEEE Global Telecommunications Conference
BT - 2010 IEEE Global Telecommunications Conference, GLOBECOM 2010
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 53rd IEEE Global Communications Conference, GLOBECOM 2010
Y2 - 6 December 2010 through 10 December 2010
ER -