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Access reservation based on slotted ALOHA is commonly used in wireless cellular access. In this paper we investigate its enhancement based on the use of physical-layer network coding and signature coding, whose main feature is enabling simultaneous resolution of up to K users contending for access, where K ≥ 1. We optimise the slot access probability such that the expected throughput is maximised...
This paper analyses the communication performance for visible light communication (VLC) with Manchester encoded amplitude modulation. In particular, it considers the ripple generated by the LED driver as an important noise contribution for VLC. The ripple depends on the oscillation frequency of the converter which typically is chosen to satisfy other performance criteria such as power conversion efficiency...
We propose a probabilistic handshake mechanism for all-to-all broadcast coded slotted ALOHA. We consider a fully connected network where each user acts as both transmitter and receiver in a half-duplex mode. Users attempt to exchange messages with each other and to establish one-to-one handshakes, in the sense that each user decides whether its packet was successfully received by the other users:...
Energy-efficiency, high data rates and secure communications are essential requirements of the future wireless networks. In this paper, optimizing the secrecy energy efficiency is considered. The optimal beamformer is designed for a MISO system with and without considering the minimum required secrecy rate. Further, the optimal power control in a SISO system is carried out using an efficient iterative...
Device-to-device (D2D) proximity discovery enables spectral reuse via D2D communications as well as a range of innovative proximity services, such as enhanced social networking and location services. To develop a scalable discovery mechanism, signals transmitted by geographically disparate devices should not differ drastically in their received power at each monitoring device. Discovery schemes are...
We study secure communication in which a transmitter wants to send confidential messages to an arbitrary number of receivers in the presence of an external eavesdropper. We consider two classes of Gaussian channels: the Gaussian single-input single-output (SISO) multi-receiver wiretap channel and the degraded Gaussian multiple-input multiple-output (MIMO) multi-receiver wiretap channel. These two...
We consider a cooperative communication system where source and destination exchange messages with the help of relays. We investigate a scenario where the relays are not equipped with fixed batteries but collect the required energy (for processing and transmission purposes) via simultaneous wireless information and power transfer (SWIPT). We assume the relays are randomly distributed in the scenario...
We propose an uncoordinated all-to-all broadcast protocol for periodic messages in vehicular networks based on coded slotted ALOHA (CSA). Unlike classical CSA, each user acts as both transmitter and receiver in a half-duplex mode. As in CSA, each user transmits its packet several times. The half-duplex mode gives rise to an interesting design trade-off: the more the user repeats its packet, the higher...
A multi-tier architecture consisting of a macrocell overlaid with small cells, e.g., pico base station (BS), with provision of relays and device-to-device (D2D) communication is needed to satisfy the quality-of-service (QoS) requirements in a joint spectrum and energy efficient manner for the future Fifth generation (5G) networks. D2D communication enables the users located in close proximity to each...
Passive localization based on distributed MIMO radar has a wide variety of applications ranging from security/military to consumer support. This paper considers the problem of localizing a (passive) target through time-of-arrival measurements from a number of (distributed) single-antenna transmitters to distributed receivers in the presence of objects that can block the line of sight between transmitter/receiver...
In the Long Term Evolution (LTE) based device-to-device (D2D) communication systems, there are two resource access modes, i.e., eNB scheduled and random access. The eNB scheduled resource access gives flexibility to eNB with additional signalling overhead. The random access scheme is simple without the eNB control but has the drawback of data collision. In this paper, we propose a collision-aware...
Device-to-device (D2D) communication enables users lying in close proximity to bypass the cellular base station (BS) and transmit to one another directly. This offloads traffic from the cellular network, improves spatial frequency reuse and energy efficiency in the network. We present a comprehensive and tractable analytical framework for D2D-enabled uplink cellular networks with two different flexible...
We propose and analyze the performance of full-duplex relay selection in primary/secondary spectrum-sharing networks. Contrary to half-duplex relaying, full-duplex relaying (FDR) enables simultaneous listening/forwarding at the secondary relay, thereby allowing for a higher spectral efficiency. However, since the source and relay simultaneously transmit in FDR, their superimposed signal at the primary...
We present a performance evaluation of ITLinQ and FlashLinQ, the two most popular schemes proposed to date to channelize D2D transmissions, i.e., to parse transmissions into noninterfering sets to be allocated to separate channels. Recognizing that it captures well the spatial characteristics of D2D networks, a stochastic geometry setting is utilized for this evaluation with the parameters of either...
The energy efficiency and delivery robustness are two critical issues for low duty cycled wireless sensor networks. The asynchronous receiver-initiated duty cycling media access control (MAC) protocols have shown the effectiveness through various studies. In receiver-initiated MACs, packet transmission is triggered by the probe of receiver. However, it suffers from the performance degradation incurred...
Machine Type Communication (MTC) is becoming an integral part of the Long Term Evolution — Advanced (LTE-A) cellular network. Challenges arise when some of the MTC devices, due to the nature of their applications, are deployed in low signal locations. As per 3GPP requirements, there is a need for additional coverage enhancement up to 20 dB in comparison with LTE category 1 UE for MTC devices. In the...
One of the most popular approaches to improving bandwidth efficiency is the use of signals with inter-symbol interference (ISI). In this paper bandwidth-efficient partial response signals (PRS) are analyzed in combinations with 4-QAM, 8-QAM and 16-QAM signal constellations and recursive systematic convolutional codes. We simulated transmission of encoded data through AWGN channel using the optimal...
In many wireless communication systems such as radars, radio-navigation and radio - synchronization systems, the exploited radio signals must possess the so-named ideal auto - correlation function (ACF), resembling the Dirac delta - function (pulse). For many classes of phase manipulated (PM) signals it is possible to transform their periodic ACFs (PACFs) in ideal PACFs by the so-named side-lobe suppression...
In this paper, a new overlay spectrum sharing protocol based on signal space diversity (SSD), is proposed for cognitive radio networks. The considered network comprises of one licensed primary transmitter/receiver (PT/PR) pair and one secondary transmitter/receiver (ST/SR) pair assisting for cooperation before transmitting its own signal on the licensed primary user's spectrum. The overall transmission...
Named Data Networking (NDN) is currently a hot research topic in the field of network architecture, and its transport control mechanism is one of the key technologies needed to be studied. Since the transport in NDN network has the characteristic of multi-source, the implicit congestion detection mechanism of the traditional TCP protocol is no longer suitable for the NDN network. In this paper, we...
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