Understanding the evolutionary mechanisms that promote and maintain cooperative behavior is recognized as a major theoretical problem where the intricacy increases with the complexity of the participating individuals. This is epitomized by the diverse nature of Human interactions, contexts, preferences and social structures. Here we discuss how social diversity, in several of its flavors, catal...

The performance of cooperative diversity with opportunistic beamforming is analyzed in rayleigh fading channels. Cooperative communication is viewed as a method for increasing diversity gain and reducing end to end path loss. The use of relays can create a virtual antenna array so that it allows users to exploit the advantages of multiple input multiple output (MIMO) techniques. In this paper w...

Cooperative diversity is an innovative approach to improve the reliability of communication. Although this technique is considered in the next-generation mobile communication standards, it has its own challenges in practice. For example, in simultaneous transmission-based cooperative protocols, perfect synchronisation of nodes is very hard to realise. The traditional time division multiple acce...

We propose a novel cluster based cooperative spectrum sensing algorithm to save the wastage of energy, in which clusters are formed using fuzzy c-means (FCM) clustering and a cluster head (CH) is selected based on a sensor's location within each cluster, its location with respect to fusion center (FC), its signal-to-noise ratio (SNR) and its residual energy. The sensing information of a single ...

In order to achieve high data rate and increase the spectral efficiency, multiple input multiple output (MIMO) system has been proposed. However, multiple antennas are limited by size and cost. Therefore, recently developed cooperative diversity scheme, which profits the transmit diversity only with the existing hardware by constituting a virtual antenna array, can be a solution. However, most ...

Cooperative diversity is a novel technique for conveying information in wireless networks, where closely located single-antenna network nodes cooperatively transmit and/or receive by forming virtual antenna arrays. For the simplest cooperative setup with two transmitters and two receivers, we first present the latest advances made in determining the theoretical capacity bounds and point out the...

Outage behavior of non-orthogonal selection decode-and-forward (NSDF) relaying protocol over an asynchronous cooperative network is examined when orthogonal frequency division multiplexing (OFDM) is used to combat synchronization error among the transmitting nodes. It is proved that the asynchronous protocol provides diversity gain greater than or equal to the one of the corresponding synchrono...

Future wireless communications technology should fulfill the demands of multimedia applications, interactive internet service, high data rates and power efficiency. However, wireless channel is affected by multipath fading that can degrade the system performance. To overcome the problem, cooperative communication has been introduced to be an efficient diversity technique to combat the multipath...

Abstract. We propose a notion of extended dominating set whereby each node in an ad hoc network is covered by either a dominating neighbor or several 2-hop dominating neighbors. This work is motivated by cooperative communication in ad hoc networks where transmitting independent copies of a packet generates diversity and combats the effects of fading. In this paper we propose several efficient ...

Cooperative diversity has emerged as a major technique of providing gains from spatial diversity to devices/terminals. While ultra-wideband (UWB) offers high information rates for wireless communication and sensor networks, the EIRP limits on UWB devices severely affects its coverage radius. In this paper, a low complexity cooperative diversity scheme for UWB channel is proposed. The scheme use...