The authors investigate the effect of feedback delay on the average capacity of a decode-and-forward cooperative network with relay selection. In particular, a multi-relay cooperative scenario is considered, where the best relay is selected from a subset of relays that are able to decode the source information correctly. In this selection scenario, the authors assume that the destination termin...

The authors study the design of cooperative beamforming for an underlay cognitive relay network over frequency selective fading channels. The network under consideration consists of one primary link, one secondary link and relay nodes that assist the communication. It is assumed imperfect blind channel estimation, i.e. only the second order statistics – with uncertainty – of the channel gain be...

We consider a full-duplex state-dependent relay channel with state non-causally available at only the relay. In the framework of cooperative wireless networks, some specific terminals can be equipped with cognition capabilities, i.e, the relay in our model. In the discrete memoryless (DM) case, we obtain inner and outer bounds on the capacity. The inner bound is obtained by a coding scheme at t...

In this paper, a direct/cooperative relay switched single carrier-frequency division multiple access (SC-FDMA) using amplify-andforward (AF) protocol and spectrum division/adaptive subcarrier allocation (SDASA) is proposed. Using SDASA, the transmit SC signal spectrum is divided into sub-blocks, to each of which a different set of subcarriers (resource block) is adaptively allocated according t...

The K-user MIMO Y-channel consisting of K users which want to exchange messages among each other via a common relay node is studied in this paper. A transmission strategy based on channel diagonalization using zero-forcing beam-forming is proposed. This strategy is then combined with signal-space alignment for network-coding, and the achievable degrees-of-freedom region is derived. A new degree...

In this paper, we propose a robust relay precoder in the multiple operator relay sharing system, where multiple base stations transmit to their target user terminals simultaneously with the assistance of an amplify-and-forward relay. The base stations and the user terminals are equipped with single antennas while the relay employs multiple antennas. The channel state information at the relay is...

In this paper, we obtain a general achievable rate region and some certain capacity theorems for multiple-access relay channel (MARC), using decode and forward (DAF) strategy at the relay, superposition coding at the transmitters. Our general rate region (i) generalizes the achievability part of Slepian-Wolf multiple-access capacity theorem to the MARC, (ii) extends the Cover-El Gamal best achi...

Cooperative communication through decode and forward (DF) relaying is an effective solution for mitigating channel fading in wireless systems. We consider a cooperative diversity system having a source, a relay, and a destination. The source and the relay cooperate through the DF protocol to enable the transmission of a binary phase-shift keying symbol in a flat Rayleigh fading environment. The...

We study the transmission of two correlated and memoryless sources (U, V ) over several multipleuser phase asynchronous channels. Namely, we consider a class of phase-incoherent multiple access relay channels (MARC) with both non-causal and causal unidirectional cooperation between encoders, referred to as phase-incoherent unidirectional non-causal cooperative MARC (PI-UNCC-MARC), and phase-inc...

This letter proposes a robust joint linear precoding scheme based on the minimum mean squared error (MMSE) criterion for amplifyand-forward (AF) multiple-input multiple-output (MIMO) relay broadcast systems with limited feedback, where only the quantized channel direction information (CDI) of the forward channel is available for the base station (BS) and the relay station (RS). The proposed sch...