TY - JOUR
T1 - A new beamforming design for MIMO AF relaying systems with direct link
AU - Kong, Han Bae
AU - Song, Changick
AU - Park, Haewook
AU - Lee, Inkyu
PY - 2014/1/1
Y1 - 2014/1/1
N2 - In this paper, we propose a new beamforming technique that maximizes the end-to-end signal-to-noise ratio (SNR) foramplify-and-forward multiple-input-multiple-output cooperative relaying systems with direct link between thesource and the destination. Instead of conventional schemes resorting to an iterative method, such as a gradient ascentalgorithm, our scheme provides a simple closed-form solution for source-relay joint beamformer designs. To this end, wefirst derive a new expression of the end-to-end SNR for the cooperative relaying systems and its lower bound, which isgiven as the harmonic mean of two individual SNRs. Then, a new beamforming scheme, which adaptively optimizes one of thetwo SNRs depending on the channel condition, is proposed. In addition, we perform a diversity order analysis of theproposed scheme and show that our scheme achieves a full diversity order of relaying systems with direct link. It isconfirmed by simulation results that the proposed technique obtains almost identical performance to the gradient ascentalgorithm with much reduced complexity, and our analytical work accurately predicts the numerical results.
AB - In this paper, we propose a new beamforming technique that maximizes the end-to-end signal-to-noise ratio (SNR) foramplify-and-forward multiple-input-multiple-output cooperative relaying systems with direct link between thesource and the destination. Instead of conventional schemes resorting to an iterative method, such as a gradient ascentalgorithm, our scheme provides a simple closed-form solution for source-relay joint beamformer designs. To this end, wefirst derive a new expression of the end-to-end SNR for the cooperative relaying systems and its lower bound, which isgiven as the harmonic mean of two individual SNRs. Then, a new beamforming scheme, which adaptively optimizes one of thetwo SNRs depending on the channel condition, is proposed. In addition, we perform a diversity order analysis of theproposed scheme and show that our scheme achieves a full diversity order of relaying systems with direct link. It isconfirmed by simulation results that the proposed technique obtains almost identical performance to the gradient ascentalgorithm with much reduced complexity, and our analytical work accurately predicts the numerical results.
KW - diversity methods
KW - MIMO systems
KW - relays
KW - transceivers
UR - http://www.scopus.com/inward/record.url?scp=84904806335&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84904806335&partnerID=8YFLogxK
U2 - 10.1109/TCOMM.2014.2326881
DO - 10.1109/TCOMM.2014.2326881
M3 - Article
AN - SCOPUS:84904806335
VL - 62
SP - 2286
EP - 2295
JO - IEEE Transactions on Communications
JF - IEEE Transactions on Communications
SN - 0090-6778
IS - 7
M1 - 6823653
ER -