Providing efficient and reliable data transport is a challenging problem for a variety of emerging applications which require reliable data packet delivery in wireless networks. In this paper, we propose to incorporate fountain codes at transport layer in the notion of cooperative relay communications to provide reliability and robustness for data transmission in wireless networks. Our basic id...

The need to support applications that are distributed on wide-local area networks or on multicomputer systems and that require large data transfer and low delay, drives the development of faster and more efficient ways of transporting and switching data. This work has led to the definition of new communication protocols and to the introduction in the telecommunication networks of fast packet-ba...

We derive the capacity of the state-dependent half-duplex relay channel without source-destination link. The output of the state-dependent half-duplex relay channel depends on the randomly varying channel states of the source-relay and relay-destination links, which are known causally at all three nodes. For this channel, we prove a converse and show the achievability of the capacity based on a...

In this paper the detection performance of relay based cognitive radio networks is studied. Relays are assigned in cognitive radio networks to transmit the primary user’s signal to cognitive coordinator or CPU thus achieving cooperative spectrum sensing. The soft fusion rule is used at the relays which acts as amplify and forward relays. For the detection purpose the energy detector is employed...

IEEE 802.16 is a Broadband Wireless Access (BWA) network and thus it is considered to be an alternative solution to wired broadband technologies. Relay station plays a promising role of extending the range of Base station for long distances in WiMAX networks. Relay station is suitable to areas with limited infrastructure such as rural, hilly and lakes, where it is difficult to install many Base...

In IEEE 802.16j wireless multihop networks, transmission latency from relay nodes to a gateway node is one of the important performance metrics. The transmission latency is mainly affected by a scheduling delay at every relay node, which is determined by algorithms for assigning time slots to wireless links between relay nodes. In this paper, we propose 2 kinds of time slot assignment algorithm...

In this paper we aim at characterizing the gain induced by using relay channels in a linear network under both a capacity constraint and a realistic energy model. We express a general model based on a convex optimization problem, allowing us to use numerical tools to obtain similar results for outer and inner bounds to the capacity of the full and half duplex relay channel. We then further the ...

The problem of multiservice transmission in OFDMA-based cooperative relay networks is studied comprehensively. We propose a framework to adaptively allocate power, subcarriers, and data rate in OFDMA system to maximize spectral efficiency under the constraints of satisfying multiuser multiservices’ QoS requirements. Specifically, first we concentrate on the single-user scenario which considers ...

This paper introduces and studies a model in which two relay channels interfere with each other. Motivated by practical scenarios in heterogeneous wireless access networks, each relay is assumed to be connected to its intended receiver through a digital link with finite capacity. Inner and outer bounds for achievable rates are derived and shown to be tight for new discrete memoryless classes, w...