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Underwater acoustic grid network is promising for providing high data rate and wide coverage service. For the scheduled time division multiple access (TDMA) protocols in the underwater acoustic grid networks, scheduling is an essential part to achieve reliable and energy efficient performance. Scheduling not only completely guarantees the interference free transmission in the network, but also makes...
This paper presents a ray tracing approach to optimise the position of a relay in a static environment such that the signal-to-noise ratio (SNR) is maximised at the receiver. The underlying principles behind the ray tracing wireless channel model are summarised. An implementation of a ray tracing algorithm is developed in MATLAB to calculate the channel state information (CSI) of a relay-assisted...
Bringing to the market intelligent vehicles is one of the current challenges faced by car manufacturers. These vehicles must be able to communicate in order to cooperate and be more effective. The issue of inter-vehicle communications is an active research topic. This paper proposes a reliable geographical broadcasting protocol which has a twofold goal: limiting the risk of interference and reducing...
Power consumption is a key issue for wireless network design. Cooperative routing, an efficient scheme for saving transmission power in wireless networks, combines the advantage of the cooperative communication in the physical layer and the routing technology in the network layer. In this paper, we propose a distributed minimum power cooperative routing algorithm based on optimal power allocation,...
Although a number of asynchronous physical-layer network coding (PNC) schemes have been proposed, synchronous PNC may still be preferred for its simplicity. In this paper we propose a new symbol-level synchronization scheme which reduces the misalignment to less than one hardware clock cycle period. In addition, we prototype the proposed scheme on the Universal Software Radio Peripheral (USRP) platform...
We propose an underlay decode-and-forward cognitive (UDFC) scheme under joint effects of hardware impairments at secondary users and interference constraints at multi primary receivers. In this scheme, the transmit powers of a source node and relays are constrained by interference thresholds of primary receivers in which the best relay is selected has the highest decoding capacity from the source...
In this work, we implement and demonstrate differential amplify-and-forward (DAF) cooperative relaying as a novel diversity technique to combat bit errors and outages common in airborne environments. By using differential modulation and demodulation, we reduce the system complexity by avoiding channel estimation which is often unreliable or computationally costly in dynamic environments with mobile...
In the conventional directional modulation (DM) system without relay aiding, when the eavesdropper locates within the main-beam of the desired direction, it can intercept the confidential message from source Alice. In this paper, we propose a strategy to enhance physical-layer security of direction modulation in wireless transmission with the help of multi-relay cooperation. In this scenario, the...
In recent years, GPS has been widely used as a positioning system using satellites. However, GPS receivers cannot position calculation their own positions when they can watch less than three Satellites directly. Therefore, in an environment where there are many obstacles such as urban area, there is a problem that it may be not possible to receive four or more GPS signals from GPS satellites. In this...
In this paper, we analyze the outage probability of multiple-input multiple-output cognitive cooperative radio networks (CCRNs) with multiple opportunistic amplify-and-forward relays. The CCRN applies underlay spectrum access accounting for the interference power constraint of a primary network and utilizes orthogonal space-time block coding to transmit multiple data streams across a number of antennas...
This paper considers the layered transmission between the source and the destination over two relays using super-position coding (SC). In this two-hop decode-and-forward (DF) relaying system, because of the network topology, the receiver continuously decodes only the base layer of the direct transmission from the source; the enhancement layer is decoded with a delay based on the transmission from...
Glossy is a flooding-based communication primitive for low-power wireless networks that leverages constructive interference to achieve high reliability. The Low-power Wireless Bus (LWB) uses Glossy to abstract an entire wireless network into a shared bus like topology. As Glossy is not designed as a secure communication protocol, Glossy and hence LWB are vulnerable to unauthorised eavesdropping and...
Molecular communications (MC) is a promising paradigm which utilizes molecules to implement communication among nano-machines. Cooperative relaying strategies can be used to extend communication distance and achieve reliable remote communications. In this paper, a two-hop diffusion-based molecular communication with three nano-machine nodes is considered. To mitigate the drawback of traditional cooperative...
IEEE 802.11 b/g/n enabled devices are popular and widely used to provide wireless network access. Therefore, it is often considered for configuring networks for vehicles. However, because of its short signal coverage and long link setup latency, this standard cannot be used directly to support vehicle-to-vehicle (V2V) communications. In this paper, a lightweight data dissemination protocol is proposed...
This paper investigates the performance of a cooperative spectrum sharing protocol for cognitive two-way amplify-and-forward (AF) relaying system. In the proposed framework, two primary users (PUs), PU1 and PU2 coexist with a secondary user (SU) in the same frequency band albeit with different priorities. Primary users by virtue of having a license to operate over the frequency band have higher priority...
Index modulation (IM) technique is introduced in orthogonal frequency division multiplexing (OFDM) based systems as an extension of spatial modulation (SM) principle, assuming that information is delivered to the receiver not only through symbols sent by the transmitter, but also through indices of the selected active subcarriers' set. Index modulated OFDM can be very interesting solution for 5G systems,...
In this paper, we analyze differential binary modulation for decode-and-forward (DF) based cooperative free space optical (FSO) network utilizing piecewise linear (PL) approximation and Gamma-Gamma (GG) fading links. We adopt subcarrier intensity modulation (SIM) scheme and a single relay for transmitting the binary phase shift keying (BPSK) modulated data over the FSO channels. The PL decoder considers...
Wireless surveillance is becoming increasingly important to protect the public security by legitimately eavesdropping suspicious wireless communications. This paper studies the wireless surveillance of a two-hop suspicious communication link by a half-duplex legitimate monitor. By exploring the suspicious link's two-hop nature, the monitor can adaptively choose among the following three eavesdropping...
Graph-based random access protocols have emerged as an efficient solution to tackle the medium sharing problem for machine type communications. Their remarkable performance is well-understood for scenarios in which devices communicate with a one-hop receiver devoted to collecting packets. Many practical applications, however, foresee the receiver to also act as sender towards a second-hop terminal...
This paper investigates a three-node multiple-input multiple-output relay system suffering from co-channel interference (CCI) at the multi-antenna relay. Contrary to the conventional relay networks, we consider the scenario that the relay is an energy harvesting (EH) node and has no embedded energy supply. But it is equipped with a rechargeable battery such that it can harvest and accumulate the harvested...
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