Channel estimation via training is a common method for providing imperfect channel state information (CSI) in a network. In a relay network, imperfect CSI can be efficiently provided at the relays by sending training signals from the source and the destination nodes to the relays. Providing imperfect CSI at the destination is more challenging since each relay is required to send training signal...

Relay based cooperative spectrum sensing elevates the spectrum sensing problems in harsh propagation conditions if the relay nodes are positioned suitably for the dynamic spectrum access systems. This article investigates the performance of relay based spectrum sensing (energy detection based) in myriad fading environments using the area under the receiver operating characteristic curve (AUC) p...

In-band full-duplex transmission allows a relay station to theoretically double its spectral efficiency by simultaneously receiving and transmitting in the same frequency band, when compared to the traditional half-duplex or outof-band full-duplex counterpart. Consequently, the induced self-interference suffered by the relay may reach considerable levels of power, which decreases the signal-to-...

Physical-layer network coding (PNC) is a communications paradigm that exploits overlapped transmissions to boost the throughput of wireless relay networks. A high point of PNC research was a theoretical proof that PNC that makes use of nested lattice codes could approach the information-theoretic capacity of a two-way relay network (TWRN), where two end nodes communicate via a relay node. The c...

We consider a discrete memoryless relay channel, where both relay and destination may have an incorrect estimation of the channel. This estimation error is modeled with mismatched decoders. In this paper, we provide a lower-bound on the mismatch capacity of the relay channel. Moreover, we prove that this lower-bound is indeed the exact capacity for the degraded relay channel when random coding ...

— Providing space diversity at mobile devices such as handsets, personal digital assistants (PDA), etc is costly and problematic, due to their strict space limitation. Recent studies, however, have revealed that extraordinary diversity gain, which results in the remarkable bene ts of an increased achievable transmission code-rate and a reduced information outage probability, can be obtained fro...

This paper presents an optimum amplifying relay matrix based on minimum mean square error (MMSE) criteria for the cooperative distributed wireless relay networks under channel uncertainty and total power constraint at the relay nodes. A one-source-one-destination pair node and N relay nodes are considered, which can be extended for a general case. All relays are assumed to exchange their receiv...

We consider the problem of maximizing underwater acoustic data transmission by adaptively positioning an autonomous mobile relay so as to learn and exploit spatial variations in channel performance. The acoustic channel is the main practical method of underwater wireless communication and improving channel throughput and reliability is key to improving the capabilities of underwater vehicles. P...