In this article, we propose multiple-relay selection schemes for multiple source nodes in amplify-and-forward wireless relay networks based on the sum capacity maximization criterion. Both optimal and sub-optimal relay selection criteria are discussed, considering that sub-optimal approaches demonstrate advantages in reduced computational complexity. Using semi-definite programming convex optim...

In this note, we propose a full-duplex decode-and-forward cooperative diversity scheme based on code division with orthogonal complementary codes. We consider a simple case in which a single user is assisted by a single relay to achieve cooperative diversity. When the cooperation is full-duplex, the operational delay of the relay makes the channel asynchronous and this may cause multiple-access...

Demand for high data rates is increasing rapidly for future wireless systems. This trend is due to the increase in the number of mobile subscribers that need bandwidth hungry multimedia applications anywhere, anytime. Fourth generation cellular systems like IMT-advanced are being developed to meet these requirements. The unreliable nature of the wireless medium is one of the main hinderance in ...

In this paper, resource allocation for a relay-based multi-user Orthogonal Frequency-Division Multiple Access (OFDMA) uplink system is studied. All the relays adopt the decode-and-forward protocol and assist the transmission from the source to destination. In current wireless networks, the terminal depends more on battery power. Given that, battery life is limited, prolonging the service life o...

Round Robin based Intermittent Periodic Transmit (RR-IPT) has been proposed which achieves highly efficient multi-hop relays in multi-hop wireless backhaul networks (MWBN) where relay nodes are 2-dimensionally deployed. This paper newly investigates multi-channel packet scheduling and forwarding scheme for RR-IPT. Downlink traffic is forwarded by RR-IPT via one of the channels, while uplink tra...

In this paper, we investigate the joint design of channel and network coding in bidirectional relaying systems and propose a combined low complexity physical network coding and LDPC decoding scheme. For the same LDPC codes employed at both source nodes, we show that the relay can decode the network coded codewords from the superimposed signal received from the BPSK-modulated multiple-access cha...

Problem statement: Multiple Input and Multiple Output (MIMO) system with Multihop relaying techhnique is significant and active areas of wireless communication. In a rich scattering environment MIMO antenna system provides better channel capacity and data rates than single antenna systems. To provide high throughput, reliable transmission and broad coverage, wireless relaying techniques are ess...