Abstract
A multiple-input multiple-output (MIMO) relay network comprises source, relay, and destination nodes, each of which is equipped with multiple antennas. In a previous work, we proposed a MIMO relay scheme for a relay network with a single source and destination pair in which each of the multiple relay nodes performs QR decompositions of the backward and forward channel matrices in conjunction with phase control (QR-P-QR). In this paper, we extend this scheme to a MIMO relay network employing multiple source and destination pairs. Towards this goal, we use a group nulling approach to decompose a multiple S-D MIMO relay channel into parallel independent S-D MIMO relay channels, and then apply the QR-P-QR scheme to each of the decomposed MIMO relay links. We analytically show the logarithmic capacity scaling of the proposed relay scheme. Numerical examples confirm that the proposed relay scheme offers higher capacity than existing relay schemes.
Highlights
A wireless network comprises a number of nodes connected by wireless channels
Network information theory has shown that the use of multiple relay nodes in source and destination (S-D) communications increases the capacity of the S-D system logarithmically with the number of relay nodes [1]
A similar tendency is observed, but the gap between group nulling (GN)/QR-P-QR and ZF is decreased. This is because the number of antennas at each node is reduced by half, and the receive array gain obtained in the GN/QR-P-QR scheme is decreased
Summary
A wireless network comprises a number of nodes connected by wireless channels. Using internode transmission (relaying) is an important technique to widen network coverage. The relay technique in [12], called QR-P-QR, performs the QR decomposition (QRD) in the backward and forward channels in conjunction with employing phase control at each relay node, and successive interference cancellation (SIC) at the destination node to detect multiple data streams. This architecture achieves both distributed array gain and receive array gain while maintaining the maximum spatial multiplexing gain, which leads to higher capacity than the existing zero-forcing (ZF) and amplify and forward (AF) relaying techniques [11]. We analyze the asymptotic capacity of the proposed relay technique and through numerical examples show that the proposed relay
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call