This survey paper presents the state-of-the-art directional medium access control (MAC) protocols in wireless ad hoc and sensor networks (WAHSNs). The key benefits of directional antennas over omni-directional antennas are longer communication range, less multipath interference, more spatial reuse, more secure communications, higher throughput and reduced latency. However, directional antennas ...

This thesis investigates channel-coded physical layer network coding, in which the relay directly transforms the noisy superimposed channel-coded packets received from the two end nodes, to the network-coded combination of the source packets. This is in contrast to the traditional multiple-access problem, in which the goal is to obtain each message explicitly at the relay. Here, the end nodes A...

In this paper, we consider a Joint Network Channel Decoding (JNCD) algorithm applied to a wireless network consisting to M users. For this purpose M sources desire to send information to one receiver by the help of an intermediate node which is the relay. The Physical Layer Network Coding (PLNC) allows the relay to decode the combined information being sent from different transmitters. Then, it...

Optimal precoding in the relay is investigated to maximize ergodic capacity of a multiple antenna relay channel. The source and the relay nodes are equipped with multiple antennas and the destination with a single antenna. It is assumed that the channel covariance matrices of the relay’s receive and transmit channels are available to the relay, and optimal precoding at the relay is investigated...

In this paper, a game theoretic relay load balancing and power allocationscheme is proposed for downlink transmission in a decode-and-forward orthogonal frequency division multiple access-based cellular relay network. A system with a base station communicating with multiple users via multiple relays is considered. The relays have limited power, which must be divided among the users they support...

We investigate massive access in the Internet-of-Things (IoT) relying on multi-pair two-way amplify-and-forward (AF) relay systems using multiple-input multiple-output (MIMO). utilize approximate message passing (AMP) algorithm for joint device activity detection and channel estimation. Furthermore, we analyze achievable rates multiple pairs of active devices derive closed-form expressions both...

Physical-layer network coding (PNC) is a novel cooperative technique for two-way relay channel (TRC), where two users exchange information via intermediate relay node(s). On the other hand, the issue of green communications to reduce energy consumption has recently started to arouse much attention. This article studies the energyefficient resource allocation problem for orthogonal frequency div...

This paper considers the partial decode-and-forward (PDF) strategy for the Gaussian multiple-input multiple-output (MIMO) relay channel. Unlike for the decode-and-forward (DF) strategy or pointto-point (P2P) transmission, for which Gaussian channel inputs are known to be optimal, the input distribution that maximizes the achievable PDF rate for the Gaussian MIMO relay channel has remained unkno...

This paper deals with the performance of two different access techniques for the Two-Hop Decode-and-Forward (DF) Multiple-Access Relay Channel (MARC) which includes multiple source and relay nodes. In particular, cooperative Orthogonal Frequency Division Multiplexing (cOFDM) is compared with distributed Interleave Division Multiplexing Space-Time Codes (dIDM-STC). While cOFDM requires strict sy...