In this study, two hop non-regenerative Multiple Input Multiple Output (MIMO) relay network is considered. Each node of the network is equipped with multiple antennas. We apply an efficient linear processing at the relay node only. We utilize Minimum Mean Square Error (MMSE) as the relay receive beamforming and PerAntenna-Signal to Leakage plus Noise Ratio (PA-SLNR) maximization criteria using ...

This paper analyzed the performance of multihop relay cooperative spectrum sensing. The closed form expression of the upper bound of the detection probability of multi-hop relay cooperation is derived in Rayleigh flat fading channel. It provides the theoretical basis for analyzing the performance of multi-hop relay cooperative spectrum sensing. Simulation results show that the detection probabi...

In 1987, Cover proposed an interesting problem in the simple relay channel [1] as shown in figure 1. In this channel, pp(yy11,yy22|xx) = pp(yy11|xx)pp(yy11|xx) and the channel from YY11 to YY22 does not interfere with YY22. Denote the rate from YY11 to YY22 as CC00. The critical value of CC00 such that CC(CC00) first equals CC(∞) is determined in this paper. In order to achieve this, a new deco...

We present capacity bounds and achievable rates of the Gaussian relay channel. To evaluate achievable rates we consider two cooperative strategies: decode and forward (DF) and compress and forward (CF). We investigate the impact of different channel conditions of the transmitter-relay, relay-receiver, and transmitter-receiver transmission on the bounds and rates. We also compare the results to ...

This paper focuses on Byzantine attack detection for Gaussian two-way relay network. In this network, two source nodes communicate with each other with the help of an amplify-and-forward relay which may perform Byzantine attacks by forwarding altered symbols to the sources. For simple investigating the detectability of attacks conducted in Gaussian channels, we focus on the MA channel of the ne...

We study the interference channel with a signal cognitive relay. A signal cognitive relay knows the transmit signals (but not the messages) of the sources non-causally, and tries to help them communicating with their respective destinations. We derive upper bounds and provide achievable schemes for this channel. These upper and lower bounds are shown to be tight from generalized degrees of free...

Two-way relay is potentially an effective approach to spectrum sharing and aggregation by allowing simultaneous bidirectional transmissions between source-destinations pairs. This paper studies the two-way 2×2×2 relay network, a class of four-unicast networks, where there are four source/destination nodes and two relay nodes, with each source sending a message to its destination. We show that w...

We give a comprehensive discussion on coding techniques for the primitive relay channel, in which the channel input X is transmitted to the relay Y1 and the ultimate receiver Y over a channel p(y, y1|x) and the relay can facilitate the communication between the transmitter and the receiver by sending some information to the receiver over a separate noiseless link of capacity R0. In particular, ...

This paper studies upper bounds and lower bounds on the outage capacity and ergodic capacity of a three-node wireless relay channel in a Rayleigh fading environment. We also take into account practical constraints on the transmission duplexing at the relay node and on the synchronization between the source node and the relay node. We find that the gap between the upper bounds and lower bounds i...

A simple technique to secure quantum key distribution relay networks is presented here. The paper introduces the concept of logical channels that uses a random dropout scheme. The paper also presents an enhanced protocol for key distribution in the relay networks. Previous techniques relied on creating distinct physical paths to create shares. Hence the compromise of one relay must compromise t...