Cognitive radio plays a vital role in wireless communication. The cognitive radio composed of a transceiver which is used to check the channel vacancy for communication and avoids busy channels by shifting into unused channel. The scope for spectrum vacancy and area of coverage is increased by using cognitive radio. In cooperative relay network to transmit the primary traffic the primary users ...

System Design and Outage Analysis for Cooperative Diversity Wireless Networks by Sungjoon Park Chair: Wayne E. Stark Relay communication systems have recently been gaining momentum as an alternative to cellular architectures because of the ability to provide cost-efficient high spectral efficiency communications. The goal of this thesis is to investigate opportunistic relay communication strate...

Adding fixed relay nodes (RNs) to wireless access networks requires additional costly infrastructure. Utilising mobile RNs, i.e., user terminals that relay signals intended for other users being the destination nodes (DNs), is an appealing cost-effective solution. However the changing node topology increases the required signalling for relay selection (RS). The signalling overhead consists of c...

Although radio access technology has huge expansion in the past decades, interference management is a key concern for today’s mobile communication systems, a concern in the demand by an ever increasing range of potential applications. Future wireless network including LTE-advanced(also known as the standard for the next generation mobile communication system) will not only need to support highe...

Three transmission schemes over a new type of multiple-access channel (MAC) model with inter-source communication links are proposed and investigated in this paper. This new channel model is well motivated by, e.g., wireless distributed storage networks, where communication to repair a lost node takes place from helper nodes to a repairing node over a wireless channel. Since in many wireless ne...

Physical layer network-coding for the n-way wireless relaying scenario is dealt with, where each of the n user nodes X1, X2, ..., Xn wishes to communicate its messages to all the other (n−1) nodes with the help of the relay node R. The given scheme, based on the denoise-and-forward scheme proposed for two-way relaying by Popovski et al. in [1], employs two phases: Multiple Access (MA) phase and...

In this paper, a novel and practical transmission scheme for a Multiple Input Multiple Output–Orthogonal Frequency Division Multiple Access (MIMO-OFDMA) relaybased network is proposed and evaluated.We coin the termVirtual Maximum Ratio Transmission (VMRT) for the schemewhich obtains diversity and array gain at both links in a two-hop transmission, while keeping the complexity low. Besides, the ...

In this paper, we study the transmit diversity of the cooperative relay system employing multiple-input multiple-output (MIMO) technology, especially for the Alamouti space-time block codes (STBC), over slow Rayleigh fading channel. The transmit diversity gain is achieved by STBC and cooperative technology. Maximum ratio combining (MRC) and maximum likelihood detection (MLD) are applied in the ...

Relay communications, as a promising technique to help in attaining broader coverage and combating the impairments of the wireless channel, have gained significant interests at the beginning of this century [1–3]. Recently, various cooperation protocols, for example, amplify-and-forward (AF) and decode-and-forward (DF) [2], have been proposed for cooperative wireless networks. Subsequently, the...