In this paper, we study a diamond-relay channel where the source is connected to M relays through orthogonal links and the relays transmit to the destination over a wireless multiple-access channel in the presence of an eavesdropper. The eavesdropper not only observes the relay transmissions through another multiple-access channel, but also observes a certain number of source-relay links. The l...

In this paper, we model a specific relay channel named relay multiple access channel (RMAC) aiming at providing a clue to select the relay node in multiple access channels such as the uplink of cellular communication system. In this channel, the relay node not only aids to send the information of the source but also sends its private message to the destination. We derive the achievable rate reg...

The interference channel with a cognitive relay consists of a classical interference channel with two sourcedestination pairs and with an additional cognitive relay that has a priori knowledge of the sources’ messages and aids in the sources’ transmission. We derive a new outer bound for this channel using an argument originally devised for the “more capable” broadcast channel, and show the ach...

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...

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...