In cooperative relay networks, Channel State Information (CSI) is estimated at receiver. The estimated CSI is sent back to the relays through feedback link. This estimated CSI is often outdated due to feedback delay and the estimated outdated CSI is used for relay selection and detection which affects the performance of the system. The outage and error rate performance of the relay selection sc...

This paper presents the capacity of a modulo-sum simple relay network. In previous work related to this paper, capacity was characterized for the case where the noise was transmitted to the relay. And the closed-form capacity was derived only for the noise with a Bernoulli-( distribution. However, in this paper, the source is transmitted to the relay, and a more general case of noise with an ar...

Relay selection is an attractive method to improve the bandwidth efficiency of cooperative networks [1]-[3]. Specifically, Bletsas and others [1] proposed a distributed relay selection based on the channel information of both the first and second hops for each relay, showing that the diversitymultiplexing tradeoff of relay selection is identical with that of distributed space-time coding. Recen...

The Relay Nodes has become an important radio resource in next-generation wireless communication systems. The optimal number of RNs is one of the crucial issues in configuring a cost-effective RN-based network architecture. In this work, we present a modified relay based MAC protocol to describe the impact of the number of RNs on the Throughput, end-toend delay, PDR, Overhead of MAC Protocol ba...

The limiting effect of multi-user interference from an adjacent cell upon the relays used for cooperative transmission is considered in the context of legacy networks which adopt max(min(·, ·)) type relay selection policies. We extend previous work which considered single relay selection to the selection of two or four such relays, as is required in distributed space–time coding. We obtain new ...

Cooperative diversity is a communication technique where a relay node provides signal diversity to the destination by retransmitting the signal received from the source. To find an optimal relay and maximize the resulting performance, a relay selection procedure is used with channel state information as a selection metric. In this paper, we model cooperative diversity with relay selection as a ...

In this letter, a two-slot secondary non-orthogonal multiple access (NOMA) relay is used to assist spectrum sharing, where the primary transceivers with long distance communicate through the relay. First, the information for the primary receiver (PR) and secondary receivers (SRs) is transmitted via the NOMA relay. Then, the information for PR is re-transmitted to it through a selected SR to imp...

Multi-hop relaying in cellular networks can greatly increase capacity and performance by exploiting the best available relay links to a base station. We envision an environment in which relay networks are dynamically formed when performance on the radio access network is degraded and then dissolved when the performance improves or the radio spectrum on which the relay network is operating is re...

In this paper, we investigate opportunistic relay and jammer cooperation schemes in multiple-input multiple-output (MIMO) buffer-aided relay networks. The network consists of one source, an arbitrary number of relay nodes, legitimate users and eavesdroppers, with the constraints of physical layer security. We propose an algorithm to select a set of relay nodes to enhance the legitimate users’ t...

The research on distributed MIMO relay system has been attracting much attention. In this paper, a decode-and-forward scheme distributed MIMO relay system is examined. For upper bound of channel capacity, the distance between transceivers is optimized when the propagation loss is brought close to actuality. Additionally, the number of relay is optimized whether total antenna element is fixed or...