Scientific publications—2015

2017 2016 2015 2014 2013 2012 2011 2010

Each year, CRC's researchers author a number of publications communicating successes in advanced wireless telecommunications R&D. Integral to their work is sharing the results with others.

Here you will find abstracts and links to papers published in peer-reviewed scientific journals or books or presented at conference proceedings.

If you experience issues accessing the full report or the website, please contact us. Other formats of documents are also available upon request.


Research publications—2015
Title Authors
Measurement and Characterization of Low-Altitude Air-to-Ground MIMO Channels

Year: 2015

Abstract: In this paper, the spatial characteristics of air-to-ground mobile multiple-input-multiple-output (MIMO) channels are analyzed based on measurements performed in a rural area using a multi-element transmitter mounted in an unmanned aerial vehicle. The analysis shows, that with appropriate signalling strategies, an airborne platform could provide a viable relay or broadcast node for high capacity communications using MIMO.

Source title: IEEE Transactions on Vehicular Technology

Series Number: Volume 65, Issue 4

DOI: 10.1109/TVT.2015.2419738

Link: Measurement and Characterization of Low-Altitude Air-to-Ground MIMO Channels

Willink, T.J.; Squires, C.; Colman, G. W. K.; Muccio, M. T.
Exact BER analysis of MIMO MRC systems with channel estimation error and interference

Year: 2015

Abstract: In this paper, we investigate the impact of channel estimation error on the average bit error rate (BER) of multiple-input multiple-output (MIMO) wireless systems with maximum ratio transmission (MRT) beamforming and maximum ratio combining (MRC) reception, known as MIMO MRC systems. The analysis is performed over frequency-flat Rayleigh fading channels in the presence of co-channel interference, where each interferer is assumed to be from a single transmit antenna. Previous error rate expressions in the literature are approximate and include hypergeometric functions. In contrast, the analytical result derived in this paper is exact and in the form of finite terms of elementary functions. It is verified by Monte Carlo simulations and utilized to evaluate the overestimation arising in the error rate results obtained in the literature. © 2015 Crown.

Source title: 2015 IEEE Wireless Communications and Networking Conference, WCNC 2015

DOI: 10.1109/WCNC.2015.7127546

Link: Exact BER analysis of MIMO MRC systems with channel estimation error and interference

Basri, A.A.
Energy-Efficient Power Loading for OFDM-Based Cognitive Radio Systems with Channel Uncertainties

Year: 2015

Abstract: In this paper, we propose a novel algorithm to optimize the energy efficiency (EE) of orthogonal frequency-division multiplexing (OFDM)-based cognitive radio systems under channel uncertainties. We formulate an optimization problem that guarantees a minimum required rate and a specified power budget for the secondary user (SU) while restricting the interference to primary users (PUs) in a statistical manner. The optimization problem is nonconvex, and it is transformed to an equivalent problem using the concept of fractional programming. Unlike all related works in the literature, we consider the effect of imperfect channel-state information (CSI) on the links between the SU transmitter and receiver pairs, and we additionally consider the effect of limited sensing capabilities of the SU. Since the interference constraints are met statistically, the SU transmitter does not require perfect CSI feedback from the PUs' receivers. Simulation results show that the EE deteriorates as the channel estimation error increases. Comparisons with relevant works from the literature show that the interference thresholds at the PUs' receivers can be severely exceeded and that the EE is slightly deteriorated if the SU does not account for spectrum sensing errors. © 2014 IEEE.

Source title: IEEE Transactions on Vehicular Technology

Series Number: Volume 64 Issue 6

DOI: 10.1109/TVT.2014.2342226

Link: Energy-Efficient Power Loading for OFDM-Based Cognitive Radio Systems with Channel Uncertainties

Bedeer, E.; Amin, O.; Dobre, O.A.; Ahmed, M.H.; Baddour, K.E.
Maximum Likelihood Timing Estimation for CPM using Legendre Polynomials

Year: 2015

Abstract: An algorithm to perform maximum likelihood (ML) timing estimation for continuous phase modulation (CPM) is proposed. It is shown, that a relatively simple basis function representation of several commonly used CPM signals, yields an approximate ML timing solution performing close to the lower bound for any unbiased estimator.

Source title: IEEE Wireless Communications Letters

Series Number: Volume 4 Issue 5

DOI: 10.1109/LWC.2015.2449300

Link: Maximum Likelihood Timing Estimation for CPM using Legendre Polynomials

Brown, C.; Vigneron, P.J.
Design of a multilayer X-/Ka-band frequency-selective surface-backed reflectarray for satellite applications

Year: 2015

Abstract: A dual-band X-/Military Ka-band (MKa-band) single-aperture reflectarray structure that transmits and receives at both MKa- and X-bands is introduced in this paper. Frequency selective surface (FSS) is used as the ground plane for the MKa-band reflectarray. A cascade configuration of FSS-backed reflectarrays is designed for each of the receive and transmit bands of MKa-band to reduce the coupling between the elements of these two bands when they are etched on the same substrate. Additional FSS's are implemented to further enhance the isolation between the bands. The MKa-band elements are located on top of the X-band reflectarray that is composed of elements etched on a perfect electric conductor (PEC)-backed ground plane. The reflectarray elements also convert circular to linear polarization which results in a simplified feed structure. © 1963-2012 IEEE.

Source title: IEEE Transactions on Antennas and Propagation

Series Number: Volume 63 Issue 4

DOI: 10.1109/TAP.2015.2389838

Link: Design of a multilayer X-/Ka-band frequency-selective surface-backed reflectarray for satellite applications

Chaharmir, M.R.; Shaker J.
Design of a novel dual-band 2.4/5.5 GHz Frequency Selective Surface using loop element

Year: 2015

Abstract: A novel dual-band Frequency Selective Surface (FSS) using a combination of open and closed loops is designed to block Wi-Fi signals at 2.45 GHz and 5.5 GHz and transmit the signals outside of the Wi-Fi bands. The structure was fabricated using Printed Electronics technology and good agreement between measured and simulated results was achieved.

Source title: META 15

DOI: N/A

Link: Design of a novel dual-band 2.4/5.5 GHz Frequency Selective Surface using loop element (PDF document)

Chaharmir, R.; Ethier, J.; Shaker, J.
Providing Vehicular Infotainment Service Using VHF/UHF TV Bands via Spatial Spectrum Reuse

Year: 2015

Abstract: In this paper, we identify the potential of the television bands to be used for providing vehicular infotainment service. Specifically, content delivery from the roadside unit to vehicular users is conducted by exploiting the spectrum holes, which is also referred to as spatial spectrum reuse. In this manner, the spectrum utilization efficiency is improved and the digital television service is not interfered. We first give a thorough description on such vehicular content delivery network and indicate the major design issues. After that, we respectively develop user and resource models tailored for our scenario by considering their characteristics and formulate the resource allocation as a system throughput maximization problem based on these models. For practical implementation, we devise a vehicular content delivery protocol incorporating a dynamic spectrum access algorithm and a maximal frame size design method, both of which aim at throughput and spectrum efficiency enhancement. Extensive simulations are conducted and the numerical results show the system performance is improved with our approaches. © 1963-12012 IEEE.

Source title: IEEE Transactions on Broadcasting

Series Number: Volume 61 Issue 2

DOI: 10.1109/TBC.2015.2400819

Link: Providing Vehicular Infotainment Service Using VHF/UHF TV Bands via Spatial Spectrum Reuse

Chen, J.; Liu, B.; Zhou, H.; Gui, L.; Liu, N.; Wu, Y.
Self-Organizing Scheme Based on NFV and SDN Architecture for Future Heterogeneous Networks

Year: 2015

Abstract: Future cellular networks will be of high capacity and heterogeneity. The structure and architecture will require high efficiency and scalability in network operation and management. In this paper, we address main requirements and challenges of future cellular networks and introduce network function virtualisation (NFV) with software defined networking (SDN) to realize the self-organizing (SO) scheme. NFV integrates the hardware appliances together in industry standard servers. And SDN performs as core controller of the network. The proposed SO scheme is based on soft fractional frequency reuse (SFFR) framework. The scheme takes different traffic demands into consideration and allocates the power adaptively. Finally the system is proved to be more scalable, energy-saving, and intelligent. © 2015, Springer Science+Business Media New York.

Source title: Mobile Networks and Applications

Series Number: Volume 20 Issue 4

DOI: 10.1007/s11036-015-0630-3

Link: Self-Organizing Scheme Based on NFV and SDN Architecture for Future Heterogeneous Networks

Chen, N.; Rong, B.; Mouaki, A.; Li, W.
Closer look at mosaic reflectarray antennas

Year: 2015

Abstract: Justification for the use of fragmented elements in the design of mosaic reflectarrays is provided whereby the far-field pattern performance is shown to be good in spite of the optical mosaic image, and this fact is confirmed for an additional test case of a synthesised image. Additionally, the use of sub-wavelength spaced elements, as opposed to the traditional half-wavelength spaced elements, is strongly motivated by sampling density advantages for image reproduction. © The Institution of Engineering and Technology 2015.

Source title: Electronics Letters

Series Number: Volume 51 Issue 6

DOI: 10.1049/el.2014.4344

Link: Closer look at mosaic reflectarray antennas

Ethier, J.L.T.; McNamara, D.A.; Chaharmir, M.R.; Shaker, J.
Electromagnetic Wave Propagation Modeling in a Complex Environment Using Uniform Geometrical Theory of Diffraction

Year: 2015

Abstract: In this paper, propagation mechanisms in a confined complex environment are experimentally investigated and modeled at 10 GHz. A campus student's lockers room is chosen as a propagation environment. The proposed model is implemented in Matlab using a combination of the ray tracing algorithm and uniform geometrical theory of diffraction. Moreover, a commercial ray tracing tool is used to derive wideband parameters. The comparison of analytical and experimental results reveals a strong agreement which confirm the accuracy of the developed model for prediction of electromagnetic behavior in the wireless propagation channel.

Source title: Antennas and Propagation (EuCAP), 2015 9th European Conference on

DOI: N/A

Link: Electromagnetic Wave Propagation Modeling in a Complex Environment Using Uniform Geometrical Theory of Diffraction

Fono, V.A.; Talbi, L.; Hettak, K.
Dual-band pattern-reconfigurable Yagi-Uda antenna

Year: 2015

Abstract: This paper presents a dual-band pattern-reconfigurable Yagi-Uda antenna for use in a wireless network access point. The antenna allows for dual-band operation in the 2450 MHz and 5800 MHz bands with independent radiation pattern reconfiguration in both bands. Five operational cases are presented, with the beam at the two different bands pointing in either the same or opposite directions as well as a case presenting a combination of omnidirectional and lateral directive beams. The unique antenna concept reported is a compact and efficient solution for frequency-band-independent reconfigurable radiation patterns. © 2015 IEEE.

Source title: IEEE Radio and Wireless Symposium, RWS

DOI: 10.1109/RWS.2015.7129758

Link: Dual-band pattern-reconfigurable Yagi-Uda antenna

Gagnon, N.
Editorial for MONET Special Issue on Networking in 5G Mobile Communications Systems: Key Technologies and Challenges

Year: 2015

Abstract: [No abstract available]

Source title: Mobile Networks and Applications

Series Number: Volume 20 Issue 6

DOI: 10.1007/s11036-015-0606-3

Link: Editorial for MONET Special Issue on Networking in 5G Mobile Communications Systems: Key Technologies and Challenges

Ge, X.; Rodrigues, J.J.P.C.; Rong, B.
Optimal Total-Downlink-Transmitting Power and Subchannel Allocation for Green Cellular Networks

Year: 2015

Abstract: Femtocells can be employed as the low-power "green" wireless-access points to extend the macrocell network coverage and enhance the quality-of-service inside homes. In this paper, we focus on the joint subchannel allocation and transmitting-power control for femtocells during the downlink transmissions. Our objective is to minimize the total transmitting power across femtocell access points (FAPs) to facilitate "green" mobile communications. We would like to minimize the following criteria: (1) each user's received signal-to-interference-plus-noise ratio (SINR) per subchannel and (2) the number of subchannels each femtocell user requires to maintain a reliable quality-of-service (QoS). Meanwhile, the interference of the users in the underlying femtocells to users in other macrocells should also be restricted. Thus, a new pertinent optimization problem is formulated as a mixed integer nonlinear program (MINLP), which is very complicated to solve in practice. In our work, a reformulation-linearization technique (RLT) based on a branchand-bound framework is invoked to simplify the aforementioned MINLP. Finally, simulation results are demonstrated for the effectiveness of our proposed new scheme.

Source title: IEEE ICC'15 – Wireless Communications Symposium

DOI: 10.1109/ICC.2015.7248531

Link: Optimal Total-Downlink-Transmitting Power and Subchannel Allocation for Green Cellular Networks

Guo, L.; Wu, H.-C.; Wu, Y.; Liu, X.
Spectrum Access Quality for Mobile Broadband Video Communications in Smart Cities

Year: 2015

Abstract: Cities use broadband wireless spectrum access technologies to enable a wide range of smart city applications that enhance safety and security, improve efficiency of municipal services and promote a better quality of life for residents and visitors. The most quality and bandwidth-demanding smart city scenarios usually involve video communications. New compression technologies have made the delivery of high-resolution video over access networks a reality. However, video delivery must take into account network characteristics in different environmental conditions. This paper studies the possibility of providing high resolution video in mobile environments over the downlink and uplink of a broadband wireless access network, without compromising the video quality. The downlink scenario typically corresponds to offering multicast/unicast video to mobile residents and visitors, whereas the uplink scenario can be for video surveillance for public safety and electronic news gathering. For this study, measurements were obtained using professional video streaming equipment, on a commercially available broadband wireless access system in a typical emulated mobile environment. Analysis was done for different video settings and spectrum and network configurations in order to characterize network performance and assess video quality in different conditions. A key outcome of this analysis was to determine the feasibility of high resolution video delivery over broadband wireless access networks in mobile conditions and to point recommendations for the QoE optimization of mobile video reception. A good quality of experience is possible provided that system and environment limitations are respected.

Source title: ACM Modeling, Analysis and Simulation of Wireless and Mobile Systems

DOI: 10.1145/2815347.2815359

Link: Spectrum Access Quality for Mobile Broadband Video Communications in Smart Cities

Issa, O.; Li, W.; Liu, H.
Optimization of Outdoor Video surveillance

Year: 2015

Abstract: Video surveillance has a growing importance in public safety services. Departments and organizations delivering public safety and security services often need to resort to covertness in their activities. They usually compromise on distance, lens size and light to insure secrecy; these compromises present challenges on the quality and usefulness of the captured video. Moreover, outdoor surveillance systems, especially over long distances, are often constrained to wireless networks to transport the video back to the monitoring offices.  The design of such application is multi-faceted and covers both video processing and the delivery network. In this paper, we study the challenges of video surveillance, covering most of the phases of a typical surveillance system, and present a roadmap to render the surveillance video, collected over long distances, useful in the pursuit of investigations and responsive to the requirements of different target recognition levels.

Source title: International Journal of Recent Advances in Communications and Networking Technology

Series Number: Volume 4 Issue 1

DOI: 10.2174/2215081104666150730222334

Link: Optimization of Outdoor Video surveillance

Issa, O.; Li, W.; Liu, H.; Renaud, R.
Wideband Propagation Characteristics at 312 MHz in Eastern Norway and Impact on Waveform Requirements

Year: 2015

Abstract: A wideband Pseudo-Noise channel sounder built by CRC in Canada has been used to measure the wideband channel characteristics in three different types of terrain in Eastern Norway. The channel characteristics at 312 MHz are described in terms of path loss, RMS delay spread and maximum delay interval. The multipath delays were found to be quite long containing considerable power, particularly in the mountain valley. The long delays require extensive equalization of a single carrier wideband waveform, and for a typical high data rate 5 MHz waveform at UHF, the required equalizer depth was found to be more than 100 symbol periods.

Source title: IEEE MILCOM 2015

DOI: 10.1109/MILCOM.2015.7357685

Link: Wideband Propagation Characteristics at 312 MHz in Eastern Norway and Impact on Waveform Requirements

Jodalen, V.; Pugh, J.; Vigneron, P.
A direction and relative speed (DARS)-based routing protocol for VANETS in a highway scenario

Year: 2015

Abstract: The dynamic nature of vehicular ad hoc networks (VANETs) requires efficient routing protocols for better performance. It is challenging to provide a universal routing protocol that performs well in all scenarios of VANETs. A routing protocol is challenged by vehicle speed, position, and network density. VANETs for highways are dependent on speed and direction of vehicles thus requiring customized routing protocols. This paper presents a novel direction and relative speed (DARS)-based routing protocol for highways using a single-hop packet forwarding approach. It selects the next hop using DARS of the vehicle. The experiments show significant improvement in packet delivery ratio, end-to-end delay, packet drop ratio, and Jains fairness index for proposed protocol compared to direction-based ad hoc on demand distance vector. © 2014 The Chinese Institute of Engineers.

Source title: Journal of the Chinese Institute of Engineers, Transactions of the Chinese Institute of Engineers,Series A/Chung-kuo Kung Ch'eng Hsuch K'an

Series Number: Volume 38 Issue 3

DOI: 10.1080/02533839.2014.970354

Link: A direction and relative speed (DARS)-based routing protocol for VANETS in a highway scenario

Kaleem, M.; Hussain, S.A.; Raza, I.; Chaudhry, S.R.; Raza, M.H.
Framing and Multiple-PLP Structures for LDM-based Next Generation Terrestrial Broadcasting Systems

Year: 2015

Abstract: In this paper, we present framing and multiple-physical layer pipe (PLP) structures for layered division multiplexing (LDM)-based next generation terrestrial broadcasting systems. As a framing structure, single-layer frames and multi-layer frames can be simultaneously transmitted by a time division multiplexing (TDM) approach. In addition to a conventional multiple-PLP strategy, which is basically time-divisioned, layer-divisioned multiple-PLP strategies are introduced in order to implement low complexity and high efficiency LDM systems. In the case that the cells of upper layer and lower layer are super-imposed, a practical consideration of lower layer cell indication is addressed. Performance analysis is given when multiple PLPs are serviced with different TDM and LDM configurations.

Source title: IEEE Int'l Symposium on Broadband Multimedia Systems and Broadcasting 2015 (BMSB2015)

DOI: 10.1109/BMSB.2015.7177240

Link: Framing and Multiple-PLP Structures for LDM-based Next Generation Terrestrial Broadcasting Systems

Lee, J.-Y.; Park, S.I.; Kwon, S.; Kim, H.M.; Wu, Y.; Zhang, L.; Li, W.; Montalban, J.; Angueira, P.
EM channel characteristics and their impact on MAC layer performance in underwater surveillance networks

Year: 2015

Abstract: Wireless communications and multihop networking based on electromagnetic (EM) radios have been considered as an alternative to acoustic communications in seawater because in typical applications for networked underwater sensing, EM waves are much less susceptible to multipath distortion and environmental noise. In this paper, we discuss the characteristics of EM channels in seawater and derive a novel EM signal propagation model. Based on the propagation model, we implement in the QualNet network simulator an EM underwater surveillance network for studying the impact of these unique characteristics of underwater EM channels on the media access control (MAC) layer performance. Both a single-hop network model and a multihop network model are simulated. Simulation results show that the carrier sense multiple access without or with acknowledgement (CSMAWithoutACK or CSMAWithACK, respectively) has advantages over ALOHA and multiple access with collision avoidance in terms of packet average delay, packet delivery ratio, and MAC scheme overhead. In the multihop network model, the use of CSMAWithoutACK significantly reduces the packet average delay and the MAC scheme overhead, and both CSMAWithoutACK and CSMAWithACK achieve more than 90% packet delivery ratio. Therefore, CSMAWithoutACK (with no handshaking via request-to-send and clear-to-send control packets) is the most appropriate MAC protocol to be used in multihop EM-based underwater surveillance networks. © Her Majesty the Queen in Right of Canada 2014. Reproduced with the permission of the Minister of Industry Canada.

Source title: Wireless Communications and Mobile Computing

Series Number: Volume 15 Issue 14

DOI: 10.1002/wcm.2461

Link: EM channel characteristics and their impact on MAC layer performance in underwater surveillance networks

Li, J.; Toulgoat, M.
Networking for Next Generation NBWF Radios

Year: 2015

Abstract: This work studies the networking scheme of NATO's next generation narrow band waveform (NBWF) radios. The key techniques that effectively enable the multihop capabilities for the NBWF radios are described first. Then a network emulator is developed to evaluate two critical algorithms, the link metrics mapping algorithm and the relay node selection algorithm, employing realistic network scenario parameters. Performance results are illustrated and the options for dynamic algorithm adaptation are elaborated.

Source title: IEEE MILCOM 2015

DOI: 10.1109/MILCOM.2015.7357429

Link: Networking for Next Generation NBWF Radios

Li, L.; Rutagemwa, H.; Hu, J.; Hugg, P.; Vigneron, P.; Brown, C.; Kunz, T.
Critical magnetic fields of superconducting aluminum-substituted Ba8Si42Al4 clathrate

Year: 2015

Abstract: In recent years, efforts have been made to explore the superconductivity of clathrates containing crystalline frameworks of group-IV elements. The superconducting silicon clathrate is unusual in that the structure is dominated by strong sp3 covalent bonds between silicon atoms, rather than the metallic bonding that is more typical of traditional superconductors. This paper reports on critical magnetic fields of superconducting Al-substituted silicon clathrates, which were investigated by transport, ac susceptibility, and dc magnetization measurements in magnetic fields up to 90 kOe. For the sample Ba8Si42Al4, the critical magnetic fields were measured to be HC 1 = 40.2 Oe and HC 2 = 66.4 kOe. The London penetration depth of 4360 Å and the coherence length 70 Å were obtained, whereas the estimated Ginzburg-Landau parameter of κ = 62 revealed that Ba8Si42Al4 is a strong type-II superconductor. © 2015 AIP Publishing LLC.

Source title: Journal of Applied Physics

Series Number: Volume 117 Issue 21

DOI: 10.1063/1.4921702

Link: Critical magnetic fields of superconducting aluminum-substituted Ba8Si42Al4 clathrate

Li, Y.; Garcia, J.; Franco, G.; Lu, J.; Lu, K.; Rong, B.; Shafiq, B.; Chen, N.; Liu, Y.; Liu, L.; Song, B.; Wei, Y.; Johnson, S.S.; Luo, Z.; Feng, Z.
A CPW-Fed Wide Slot Ultra-Wideband Antenna with Triple Band Rejection Characteristics

Year: 2015

Abstract: A coplanar waveguide (CPW) fed circular slot ultra-wideband (UWB) antenna with triple band-notched characteristics is proposed and its performance is evaluated by HFSS simulation and measurement. The three notch bands are realized by means of two arc-shaped parasitic elements (ASPEs) and an E-shaped stub (ESS). By adjusting the dimensions of the ASPEs and ESS, three notch bands can be tuned to filter unwanted 3.5 GHz WiMAX, 5.5 GHz WLAN and 8 GHz X-band signals. The simulated and measured results demonstrate that the proposed antenna covers the entire UWB band with voltage standing wave ratio (VSWR) less than 2 and provides three notch bands to reduce potential interferences from existing narrowband systems. Furthermore, this tri-band frequency rejection UWB antenna can provide omnidirectional radiation patterns and high rejection band-notched characteristics, which are suitable for UWB communication applications. © 2015 by De Gruyter.

Source title: Frequenz

Series Number: Volume 69 Issue 9-10

DOI: 10.1515/freq-2015-0025

Link: A CPW-Fed Wide Slot Ultra-Wideband Antenna with Triple Band Rejection Characteristics

Li, Y.; Ye, Q.
Optimization of EVM through diode bias control using a blind algorithm applied to multiport receivers

Year: 2015

Abstract: In this brief, we developed a detailed Simulink model that emulates the radio frequency and digital base band of a six-port receiver. In contrast to other results published in the literature, we not only provide a controlled continuous bias to the diodes. We propose a novel algorithm that reduces the error vector magnitude (EVM) by adaptively controlling the diode bias point. We will also show that when the algorithm is turned on in the model, the EVM becomes less sensitive to variations in the diode bias conditions. Another key feature of optimum diode bias control is that the local oscillator (LO) power requirements decrease and that the EVM is not sensitive to LO power variation. Results presented here show that for an LO power variation of more than 10 dB, we notice no EVM variation. © 2004-2012 IEEE.

Source title: IEEE Transactions on Circuits and Systems II: Express Briefs

Series Number: Volume 62 Issue 3

DOI: 10.1109/TCSII.2014.2362792

Link: Optimization of EVM through diode bias control using a blind algorithm applied to multiport receivers

Lima, J.A.; Rogers, J.M.W.; Amaya, R.E.
Overview of Wireless Microphones - Part I: System and Technologies

Year: 2015

Abstract: Wireless microphones are indispensable to modern society. They are used worldwide by professionals and amateurs for such applications as live performances, electronic news gathering, and conference presentations. Due to the radio spectrum crunch, wireless microphones have become a hot topic of discussion and debate among television broadcasters, wireless microphone manufacturers, wireless network operators, and spectrum regulators. In order to keep wireless microphones operating well, it is necessary to give engineers, researchers, and regulators a comprehensive overview of wireless microphones in the aspects of technologies, spectrum requirements, and interference that may be experienced or generated by wireless microphones. This overview is divided into two parts. Part I provides an overview of typical wireless microphone system components, their performance requirements and technical parameters, and the technologies that are used in current wireless microphones. Part II focuses on the spectrum, sources of interference, and regulations surrounding wireless microphones. © 1963-12012 IEEE.

Source title: IEEE Transactions on Broadcasting

Series Number: Volume 61 Issue 3

DOI: 10.1109/TBC.2015.2459661

Link: Overview of Wireless Microphones - Part I: System and Technologies

Liu, H.; McLachlan, D.; Wang, D.
Overview of Wireless Microphones-Part II: Frequency Bands, Interference, and Regulation

Year: 2015

Abstract: Most wireless microphones operate on vacant television broadcasting channels in the very high frequency and ultrahigh frequency bands, as secondary users operating on the no-interference and no-protection basis. Some wireless microphones share the 2.4 GHz band with other wireless devices. The 698-806 MHz band was repurposed when television broadcasting switched from analog to digital (and the 600 MHz band may be repurposed in the near future), resulting in less spectrum available for wireless microphone operations. To keep wireless microphones operating effective in this environment, engineers, researchers, and regulators require comprehensive knowledge of the spectrum, interference, and regulations regarding wireless microphones. This paper first presents the characteristics of the frequency bands currently allocated for wireless microphone operations. Next, interference that may be experienced by wireless microphones and frequency coordination required to allow multiple microphones to work together at the same site without interference are presented. Finally, it summarizes the regulations in Canada, United States of America, European Union, and Australia for wireless microphones regarding allowable transmitter frequency, power, bandwidth, channel masks, maximum frequency deviation for FM, and spurious emissions. © 1963-12012 IEEE.

Source title: IEEE Transactions on Broadcasting

Series Number: Volume 61 Issue 3

DOI: 10.1109/TBC.2015.2459662

Link: Overview of Wireless Microphones-Part II: Frequency Bands, Interference, and Regulation

Liu, H.; McLachlan, D.; Wang, D.
Monolithic-Integrated MEMS-Tunable Reflective Cell for Ku-Band Mobile Satellite Two-Way Connectivity

Year: 2015

Abstract: This paper presents the design and measurement of a single-layer micro-electromechanical system (MEMS)-tunable reflective unit cell with orthogonally polarized dual bands for Ku-band mobile satellite connectivity. Six capacitive MEMS switches across each slot of a cross-slotted patch tune its reflection phase at 12 GHz (reception) with vertical polarization and 14 GHz (transmission) with horizontal polarization. This unit cell provides four phase states with overall phase swing of 200° and 180° and average reflection amplitude of -0.79 and -0.69 dB at the lower and upper bands, respectively. This unit cell can be used for generation of an independently controlled beam at each of its operating bands. A monolithic process is also developed for the fabrication of this reflective cell along with the dedicated dc bias network. For unit cell measurements, a custom-designed waveguide setup with four DC pins was fabricated for simultaneous and independent control of all MEMS switches. The measurement results are in good agreement with simulations. © 1963-2012 IEEE.

Source title: IEEE Transactions on Antennas and Propagation

Series Number: Volume 63 Issue 4

DOI: 10.1109/TAP.2015.2391275

Link: Monolithic-Integrated MEMS-Tunable Reflective Cell for Ku-Band Mobile Satellite Two-Way Connectivity

Moghadas, H.; Daneshmand, M.; Mousavi, P.; Chaharmir. M.R.; Shaker, J.
Performance Study of Layered Division Multiplexing Based on SDR Platform

Year: 2015

Abstract: Two of the main drawbacks of the current broadcasting services are, on the one hand, the lack of flexibility to adapt to the new generation systems requirements, and on the other hand, the incapability of taking a piece of the current mobile services market. In this paper, layered division multiplexing (LDM), which grew out of the concept of Cloud Txn, is presented as a very promising technique for answering those challenges and enhancing the capacity of broadcasting systems. The major contribution of this paper is to present the first comprehensive study of the LDM performance behavior. In particular, in this paper, the theoretical considerations of the LDM implementation are completed with the first computer based simulations and laboratory tests, covering a wide range of stationary channels and the mobile TU-6 channel. The results will support LDM as a strong candidate for multiplexing different services in the next generation broadcasting systems, increasing both flexibility and performance. © 1963-12012 IEEE.

Source title: IEEE Transactions on Broadcasting

Series Number: Volume 61 Issue 3

DOI: 10.1109/TBC.2015.2432463

Link: Performance Study of Layered Division Multiplexing Based on SDR Platform

Montalban, J.; Angulo, I.; Regueiro, C.; Wu, Y.; Zhang, L.; Park, S.-I.; Lee, J.-Y.; Kim, H.M.; Velez, M.; Angueira, P.
On Radiation Performances of Reflectarray Antennas Constructed With Subwavelength Unit Cells

Year: 2015

Abstract: Multi-element approach is utilized to increase the phase variation range of a square-ring subwavelength unit cell (UC) from 313° to more than 560°. Radiation characteristics of three thin reflectarray antennas (TRAs) constructed with the proposed UCs are investigated. This investigation demonstrates that to achieve a broadband highly efficient TRA, the employed λ/5 - UC must have reflection loss considerably less than 0.1dB and its co nstructing elements should also scatter the incident fields in the same fashion, i. e., the current distributions of all parts of the multi-element UC are of the same shape and co-phased.

Source title: IEEE antennas and wireless propagation letters

Series Number: Volume 14

DOI: 10.1109/LAWP.2015.2401335

Link: On Radiation Performances of Reflectarray Antennas Constructed With Subwavelength Unit Cells

Niroo-Jazi, M.; Chaharmir, M.R.; Shaker, J.; Sebak, A.R.
Gateway Placement and Packet Routing for Multihop in-Vehicle Internet Access

Year: 2015

Abstract: In-vehicle Internet access is one of the main applications of vehicular ad hoc networks (VANETs), which aims at providing the vehicle passengers with a low-cost access to the Internet via on-road gateways. This paper introduces a new strategy for deploying Internet gateways on the roads, together with a novel scheme for data packet routing, in order to allow a vehicle to access the Internet via multihop communications in a VANET. The gateway placement strategy is to minimize the total cost of gateway deployment, while ensuring that a vehicle can connect to an Internet gateway (using multihop communications) with a probability greater than a specified threshold. This cost-minimization problem is formulated using binary integer programming, and applied to a realistic city scenario, consisting of the roads around the University of Waterloo, Waterloo, ON, Canada. To the best of our knowledge, the proposed deployment strategy is the first study to address the probability of multihop connectivity among the vehicles and the deployed gateways. On the other hand, the developed packet routing scheme is based on a multichannel medium access control protocol, known as VeMAC, using time division multiple access. The performance of this cross-layer design is evaluated for a multichannel VANET in a highway scenario, mainly in terms of the end-to-end packet delivery delay. The end-to-end delay is calculated by modeling each relay vehicle as a queuing system, in which the packets are served in batches of no more than a specified maximum batch size. The proposed gateway placement and packet routing schemes represent a step toward providing reliable and ubiquitous in-vehicle Internet connectivity.

Source title: IEEE Transactions on Emerging Topics in Computing

Series Number: Volume 3 Issue 3

DOI: 10.1109/TETC.2015.2395077

Link: Gateway Placement and Packet Routing for Multihop in-Vehicle Internet Access

Omar, H.A.; Zhuang, W.; Li, L.
Hardware Implementation and Complexity Analysis for Layered Division Multiplexing System for ATSC 3.0

Year: 2015

Abstract: Spectrum resources for terrestrial broadcast are being reduced in all ITU-R Regions. In parallel, there are different standardization and harmonization efforts ongoing in different parts of the world. In North America, the technical tools that will compose the ATSC 3.0-standard are being currently under evaluation. In the international arena the FOBTV initiative aims at providing a framework for different regions to coordinate their technological evolution on the terrestrial broadcasting arena. In both cases, the research on innovative ways of managing the scarce spectrum resources is a key for the success of broadcasting in the VHF/UHF bands. The presentation will describe a new way of handling radio resources in broadcasting, namely: Layered Division Multiplex (LDM). The system is based on spectrum overlay transmission of two signals using a 6 MHz channel. In this way simultaneous HDTV mobile and fixed UHDTV services can be effectively delivered with improved efficiency if compared with traditional FDM and TDM multiplexing. The techniques behind this idea (overlay, coding, cancellation) as well as the implications on network planning flexibility will be tackled. The complexity and performance at the receiver side will be also covered. A summary of the laboratory and field results carried out in Canada, Korea and Spain will be included in the presentation. LDM hardware prototypes have been constructed and they will be demonstrated at the NAB Labs Future Park

Source title: NAB Broadcast Engineering conference NAB2015

DOI: N/A

Link: Hardware Implementation and Complexity Analysis for Layered Division Multiplexing System for ATSC 3.0 (PDF document)

Park, S.I.; Lee, J.-Y.; Wu, Y.; Zhang, L.; Li, W.; Montalban, J.; Angueira, P.; Kwon, S.; Kim, H.M.; Hur, N.; Kim, J.
Two dimensional code based on low density parity check and reed-solomon codes for the terrestrial cloud transmission system

Year: 2015

Abstract: In this paper, we propose a two dimensional (2-D) code based on a vertical low-density parity check (LDPC) code and a horizontal Reed-Solomon code for the cloud transmission system. The proposed 2-D code shows superior performance under fading channels due to its inherent block-type interleaving feature. Furthermore, the proposed 2-D code can be adaptively decoded to reduce decoding latency and complexity because the vertical LDPC code has raptor-like rate-compatible feature. © 2015 IEEE.

Source title: IEEE Transactions on Broadcasting

Series Number: Volume 61 Issue 1

DOI: 10.1109/TBC.2014.2370111

Link: Two dimensional code based on low density parity check and reed-solomon codes for the terrestrial cloud transmission system

Park, S.I.; Wu, Y.; Kim, H.M.; Kwon, S.; Zhang, L.; Hur, N.; Kim, J.
Low Complexity Layered Division Multiplexing System for the Next Generation Terrestrial Broadcasting

Year: 2015

Abstract: This paper proposes a novel low-complexity layered division multiplexing (LDM) transmitter and receiver structures for next generation terrestrial broadcasting systems. The proposed LDM system not only has low complexity because it shares the OFDM-related chain, but also provides significant performance gain (4 to 6 dB) compared to traditional time division multiplexing (TDM) system.

Source title: 2015 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting (BMSB-2015)

DOI: 10.1109/BMSB.2015.7177208

Link: Low Complexity Layered Division Multiplexing System for the Next Generation Terrestrial Broadcasting

Park, S.I.; Wu, Y.; Zhang, L.; Montalban, J.; Lee, J.-Y.; Angueira, P.; Kwon, S.; Kim, H.M.; Hur, N.; Kim, J.
Improved-Q inductors using airbridges for GaN phase shifters

Year: 2015

Abstract: This Article proposes the use of inductors suspended in air to increase the self-resonance frequency and quality factor of inductors used in high-frequency lumped MMIC designs. This technique is compatible with MMIC processes having airbridges with no additional processing, which are quite common in III-V technologies. A measured example demonstrates lower dispersion, an increase in quality factor of 18% and a 4% increase in the self-resonance frequency of a 1 nH inductor in a GaN MMIC process with a 1 µm airbridge. As a further demonstration, the technique is applied in the design of a high-power 0°/45° switched phase shifter designed around 25 GHz. This phase shifter MMIC uses GaN HEMTs which have a peak ft of 27 GHz and offers wideband performance. © 2015 Wiley Periodicals, Inc.

Source title: Microwave and Optical Technology Letters

Series Number: Volume 57 Issue 6

DOI: 10.1002/mop.29112

Link: Improved-Q inductors using airbridges for GaN phase shifters

Ross, T.; Hettak, K.; Cormier, G.; Wight, J.S.
Design of X-band GaN phase shifters

Year: 2015

Abstract: This paper presents two different types of high-power gallium-nitride (GaN) phase shifters designed for X-band (8-12 GHz), but offering good performance over a much wider band. The first is a 22.5° switched-filter phase shifter, which has much wider bandwidth than is typically found with this configuration, while maintaining low insertion loss (<2 dB), good return loss (>11.15 dB), and an amplitude imbalance of less than 1.03 dB across X-band. The 1-dB compression point was higher than laboratory equipment was able to measure (>38 dBm) and the phase shifter monolithic microwave integrated circuit exhibited an input-referred third-order intercept point (IIP3) of 46.2 dBm. The second phase shifter is a novel design, which promises wide bandwidth (in our case, limited by the single-pole double-throw switch we have also designed), but which achieves decent insertion loss (5 dB), good return loss (better than 11 dB), and very low phase variation (1°) across X-band, also with 22.5° phase shift. It offers a 1-dB compression point of 30.1 dBm and an IIP3 of 46.3 dBm. The components for a 45° differential phase shift using the same structure were also fabricated and verified with measurements. The high-power phase shifters have been fabricated in a 0.5-µm GaN HEMT process and were designed using an accurate customized switch field-effect transistor model. © 2014 IEEE.

Source title: IEEE Transactions on Microwave Theory and Techniques

Series Number: Volume 63 Issue 1

DOI: 10.1109/TMTT.2014.2366149

Link: Design of X-band GaN phase shifters

Ross, T.N.; Hettak, K.; Cormier, G.; Wight, J.S.
Cross-layer design and performance analysis of tactical radio networks

Year: 2015

Abstract: In this paper, we investigate the performance of tactical radio networks, particularly for communication scenarios where multihop relaying along with spatial reuse techniques are applied. The tactical scenarios of concern have a diverse range of reliability and/or delay requirements. We first employ cross-layer protocol architecture with integrated time-division-multiple-Access-based fast packet forwarding and automatic-repeat-request-based multihop error control to support tactical applications with a diverse range of reliability and/or delay requirements. Then, we develop analytical models to study the link-level and network-wide behaviors of the tactical radio networks. The developed models capture the effects of end-to-end channel memory due to multihop relays, interference due to spatial reuse, uneven interslot delays due to fast packet forwarding, and jamming attack in hostile network environment. It is shown that the protocol architecture with proposed fast packet forwarding and multihop error control mechanisms can significantly improve communication performance and support delay-sensitive applications. In addition, it is demonstrated that cross-layer adaptivity, where different network environments require different logical topologies and radio modes, is needed to achieve best performance tradeoffs among throughput, efficiency, delivery ratio, and transport capacity. © 1967-2012 IEEE.

Source title: IEEE Transactions on Vehicular Technology

Series Number: Volume 64 Issue 1

DOI: 10.1109/TVT.2014.2320228

Link: Cross-layer design and performance analysis of tactical radio networks

Rutagemwa, H.; Li, L.; Vigneron, P.
Compact multi-band filter based on multi-ring complementary split ring resonators

Year: 2015

Abstract: A novel multi-band band-reject filter based on multi-ring complementary split-ring resonators (multi-ring CSRRs) is presented. The proposed filter is realized by etching the multi-ring CSRRs in the ground plane beneath a microstrip line. The multi-ring CSRR offers the possibility of designing multi-band filters with a small size and simple structure. To validate the proposed prototype of the multi-band filter, a dual-band and tri-band filters were fabricated and tested. The proposed filters show a good multi-band property to satisfy the requirement of WLAN in the 2.4/5.8GHz bands and WiMAX in the 2.5/3.4GHz bands. A good agreement between experimental and simulated results is obtained. © 2015, Electromagnetics Academy. All rights reserved.

Source title: Progress In Electromagnetics Research C

Series Number: Volume 57

DOI: 10.2528/PIERC15041904

Link: Compact multi-band filter based on multi-ring complementary split ring resonators

Sassi, I.; Talbi, L.; Hettak, K.
A novel dual-band antenna based on corrugated slotted-complementary split-ring resonators

Year: 2015

Abstract: This Article presents the design of a dual-band microstrip patch antenna. The proposed patch antenna is based on a novel metamaterial structure named the corrugated slotted-complementary split-ring resonators. By loading this new inclusion on the ground plane of a conventional patch antenna, a second resonance frequency can be created. The corrugated slotted split-ring resonator has a minor effect on the first operating band which is generated by the patch. A prototype of this antenna has been designed for operation on the industrial-scientific-medical band (2.4 GHz) and the WLAN band (5.8 GHz). The prototype has been fabricated and measured, achieving good performances for both resonance frequencies. A good agreement between experimental and simulation results is obtained. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2310-2315, 2015 © 2015 Wiley Periodicals, Inc.

Source title: Microwave and Optical Technology Letters

Series Number: Volume 57 Issue 10

DOI: 10.1002/mop.29361

Link: A novel dual-band antenna based on corrugated slotted-complementary split-ring resonators

Sassi, I.; Talbi, L.; Hettak, K.
Highly tunable microwave and millimeter wave filtering using photonic technology

Year: 2015

Abstract: The design for a photonic microwave filter tunable in both bandwidth and operating frequency is proposed and experimentally demonstrated. The circuit is based on a single sideband modulator used in conjunction with two or more transmission fiber Bragg gratings (FBGs) cascaded in series. It is demonstrated that the optical filtering characteristics of the FBGs are instrumental in defining the shape of the microwave filter, and the numerical modeling was used to optimize these characteristics. A multiphase-shift transmission FBG design is used to increase the dynamic range of the filter, control the filter ripple, and maximize the slope of the filter skirts. Initial measurements confirmed the design theory and demonstrated a working microwave filter with a bandwidth tunable from approximately 2 to 3.5 GHz and an 18 GHz operating frequency tuning range. Further work is required to refine the FBG manufacturing process and reduce the impact of fabrication errors. © 2015 Society of Photo-Optical Instrumentation Engineers.

Source title: Optical Engineering

Series Number: Volume 54 Issue 5

DOI: 10.1117/1.OE.54.5.057102

Link: Highly tunable microwave and millimeter wave filtering using photonic technology

Seregelyi, J.; Lu, P.; Paquet, S.; Celo, D.; Mihailov, S.J.
A Stackelberg Game Based Inter-tier Spectrum Sharing Scheme for LTE-A SON

Year: 2015

Abstract: This paper proposes a spectrum sharing scheme based on Stackelberg game exploiting the SON features of 3GPP LTE-A HetNets. In the game, the MeNB controls and prices the available spectrum resource which the PeNBs can purchase and use to serve the Pico-cell as well as offload some macro-users. Both kinds of nodes try to maximize their own utility which is consisted of user data rates, earning and expenditures on spectrum trading. During the dynamic interaction of the game, the interference coordination features of the LTE-A SON, such as almost blank sub-frames (ABS) of enhanced inter-cell interference coordination (eICIC) and cell range expansion (CRE), are employed so that the change of spectrum allocation can be fully exploited. Simulation results show that the proposed approach can significantly improve the throughput of victim users with slight network total throughput degradation. © 2015, Springer Science+Business Media New York.

Source title: Mobile Networks and Applications

Series Number: Volume 20 Issue 4

DOI: 10.1007/s11036-015-0629-9

Link: A Stackelberg Game Based Inter-tier Spectrum Sharing Scheme for LTE-A SON

Sun, S.; Gong, L.; Rong, B.; Mouaki, A.; Basri, A.
Integrating network function virtualization with SDR and SDN for 4G/5G networks

Year: 2015

Abstract: The rapidly diversified market demands have presented a huge challenge to the conventional mobile broadband network architecture. On one hand, the limited machine room space and insufficient power supply make it impossible to accommodate exponentially growing amount of network equipment of operators. On the other hand, net heterogeneity caused by different specifications of wireless access equipment causes costly trouble related to management and optimization. This Article, correspondingly, proposes a holistic solution involving different technologies, i.e. network function virtualization (NFV), software defined radio (SDR), and software defined network (SDN). In particular, we investigate both existing standards and possible extensions for 4G/5G mobile networks, followed by a few open issues for future research. © 2015 IEEE.

Source title: IEEE Network

Series Number: Volume 29 Issue 3

DOI: 10.1109/MNET.2015.7113226

Link: Integrating network function virtualization with SDR and SDN for 4G/5G networks

Sun, S.; Kadoch, M.; Gong, L.; Rong, B.
Self-organizing networks: First international conference, icson 2015 Beijing, China, January 13-14, 2015, revised selected papers

Year: 2015

Abstract: [No abstract available]

Source title: Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering, LNICST

Series Number: Volume 149

DOI: 10.1007/978-3-319-19746-3

Link: Self-organizing networks: First international conference, icson 2015 beijing, china, january 13-14, 2015, revised selected papers NOTE: A login may be required to access this site.

Sun, S.; Li, L.
Artificial frequency selective channel for covert cyclic delay diversity orthogonal frequency division multiplexing transmission

Year: 2015

Abstract: Multiple-input multiple-output orthogonal frequency division multiplexing has become an attractive air-interface solution for the next generation wireless networks because of its high spectrum efficiency. This paper addresses the security concern and proposes to achieve covert orthogonal frequency division multiplexing transmission using cyclic delay diversity featured multiple-input multiple-output technology. Particularly, our physical layer security scheme takes the advantage of cyclic delay diversity formed periodical frequency selective channel and utilizes uneven comb pilots to confuse unauthorized receivers and benefit authorized receivers. We conduct simulation study to evaluate the impact of different cyclic delay, antenna number, and interpolation algorithms on our scheme. Numerical results show that our scheme can provide authorized users with significant advantage over eavesdroppers without complicated upper-layer encryption and decryption. Moreover, the scheme has flexible choice of parameters and thus can be easily deployed in a variety of wireless networks with different requirements. © 2014 John Wiley & Sons, Ltd.

Source title: Security and Communication Networks

Series Number: Volume 8 Issue 9

DOI: 10.1002/sec.1118

Link: Artificial frequency selective channel for covert cyclic delay diversity orthogonal frequency division multiplexing transmission

Sun, S.; Rong, B.; Qian, Y.
MANET Security Through a Distributed Policy-Based Evaluation of Node Behaviour

Year: 2015

Abstract: While MANETs can provide seamless networking that is fast and easy to deploy, the lack of a stable topology, no centralized control, and the use of wireless links with limited bandwidth make MANETs highly vulnerable to attacks. The autonomy of individual nodes must be balanced with the need to ensure that nodes contribute to the network function as a whole. Trust-based systems are often proposed in this situation, but the mechanisms by which trust are built is still an active area of research. In this paper we present a policy-based trust management framework that uses the observed behaviour of neighbouring MANET nodes to identify and react to attacks. The system uses policy rules to evaluate observed behaviour of neighbouring nodes and reputation values shared by peers. The calculated trust values are then sent to neighbours. The calculation of trust based on a combination of flexible policy rules and distributed evaluation is a novel approach and a significant contribution of the paper. A simulation-based evaluation of our framework based on a wormhole attack shows that the scheme is both scalable and robust.

Source title: International Wireless Communications and Mobile Computing Conference, IWCMC 2015

DOI: 10.1109/IWCMC.2015.7289206

Link: MANET Security Through a Distributed Policy-Based Evaluation of Node Behaviour

Tajalli-Yazdi, A.; Lutfiyya, H.; Kidston, D.
A novel differential detection for differential OFDM systems with high mobility

Year: 2015

Abstract: In conventional differential detection (CDD), the previous received symbol is used as the phase reference for the current received symbol, therefore the channel variation due to fast fading causes an error floor. We propose a novel iterative decision-directed differential detection (iD4) algorithm for orthogonal frequency division multiplexing (OFDM) systems employing differential PSK modulation in each subcarrier. The core of iD4 is a low complexity time and frequency 2-D estimator which can effectively estimate the channel variation experienced by adjacent time domain symbols. This estimated channel variation is then compensated in the differential detection process. Both theoretical analysis and computer simulations show that significant performance improvement can be achieved using iD4 over the CDD for OFDM receivers in fast fading channels.

Source title: IEEE Trans. Broadcasting

Series Number: Volume 99

DOI: 10.1109/TBC.2015.2459656

Link: A novel differential detection for differential OFDM systems with high mobility

Zhang, L.; Hong, Z.; Wu, Y.; Boudreau, R.; Thibault, L.
Performance Characterization and Optimization of Mobile Service Delivery in LDM-Based Next Generation DTV Systems

Year: 2015

Abstract: Layered-division-multiplexing (LDM) technology is a non-orthogonal multiplexing technology to provide more efficient transmission of multiple services that have different requirements on the robustness and throughput in one TV channel. The core of LDM is to transmit multiple-layer signals, where each layer occupies the whole channel bandwidth and the whole time. To meet the different requirements on different layers, each layer is allocated a specific power level, and is configured to use a different channel coding and modulation scheme, as well as its own multiple-antenna technology. Delivering robust and high-quality mobile TV services is one of the top priorities for the next generation digital TV (NG-DTV) systems. In this paper, we first investigate the performance of the NG-DTV systems with LDM in various difficult propagation channels that are likely encountered by the large variety of mobile devices, including fast-fading channels, slow-fading channels, indoor channels, and single-frequency-network (SFN) channels. A new channel estimation technique is proposed to overcome the severe performance degradation caused by the SFN channels. We will further show that using LDM makes it possible to deliver mobile services using the efficient 32k transmission mode. Finally, receive antenna diversity is shown to provide different levels of performance improvement for different LDM configurations.

Source title: IEEE Trans. Broadcasting

Series Number: Volume 61 Issue 4

DOI: 10.1109/TBC.2015.2470103

Link: Performance Characterization and Optimization of Mobile Service Delivery in LDM-Based Next Generation DTV Systems

Zhang, L.; Li, W.; Wu, Y.; Hong, Z.; Salehian, K.; Wang, X.; Angueira, P.; Montalban, J.; Velez, M.; Park, S.-I.; Kim, H.M.; Lee, J.-Y.
Enhanced DFT-Based Channel Estimation for LDM Systems over SFN Channels

Year: 2015

Abstract: Layered-Division-Multiplexing (LDM) technology is a non-orthogonal multiplexing (NOM) technology which enables efficient transmission of multiple signals with different robustness and throughput requirements. By performing efficient noise filtering, DFT-based channel estimation (DFT-CE) method has been shown to be able to provide near-optimal performance with low complexity in a Typical Urban (TU) fading channel environment. On the other hand, in a Single-Frequency-Network (SFN) deployment, a receiver often faces the more challenging SFN channels, in which large delays are found between the signals received from different transmitters. This could significantly degrade the mobile performance of the future OFDM-based digital TV (DTV) system. In this paper, we propose a DFT-CE technique based on sub-window filtering (SubWin-DFT-CE). We show that the proposed method is able to significantly improve the mobile performance for SFN channels even with a delay spread close to the guard interval (GI) duration.

Source title: 2015 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting (BMSB-2015)

DOI: 10.1109/BMSB.2015.7177253

Link: Enhanced DFT-Based Channel Estimation for LDM Systems over SFN Channels

Zhang, L.; Wu, Y.; Li, W.; Hong, Z.; Salehian, K.; Kim, H.M.; Park, S.I.; Lee, J.-Y.; Angueira, P.; Montalban, J.; Velez, M.
Mobile and indoor reception performance of LDM-based next generation DTV system

Year: 2015

Abstract: One of the top-priority requirements for the next generation digital TV (NG-DTV) system is the capability to deliver robust services to both mobile and fixed receivers under challenging propagation conditions. One typical challenging scenario is indoor reception, where the penetration loss could be as high as 20 dB. Other challenging scenarios include outdoor mobile reception at various receiver speeds, from the very low pedestrian speed to the very high speed of high-speed trains. Layered-Division-Multiplexing (LDM) technology is a nonorthogonal multiplexing (NOM) technology which enables efficient transmission of multiple signals with different requirements on robustness and throughput. One major advantage offered by LDM is the capability to deliver extremely robust mobile high-definition TV (HDTV) services. In this paper, we present the computer simulation performances of the LDM mobile services in various challenging mobile reception environments. These performances are then compared to those of TDM-based DTV systems. We further investigate the possibility of deploying mobile service using the more challenging 32k mode. At last, receive antenna diversity is considered to achieve further mobile performance improvement.

Source title: 2015 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting (BMSB-2015)

DOI: 10.1109/BMSB.2015.7177207

Link: Mobile and indoor reception performance of LDM-based next generation DTV system

Zhang, L.; Wu, Y.; Li, W.; Hong, Z.; Salehian, S.; Kim, H.M.; Park, S.I.; Lee, J.-Y.; Angueira, P.; Montalban, J.; Velez, M.
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