18 research outputs found
Waveform Design for 5G and beyond Systems
5G traffic has very diverse requirements with respect to data rate, delay, and reliability. The concept of using multiple OFDM numerologies adopted in the 5G NR standard will likely meet these multiple requirements to some extent. However, the traffic is radically accruing different characteristics and requirements when compared with the initial stage of 5G, which focused mainly on high-speed multimedia data applications. For instance, applications such as vehicular communications and robotics control require a highly reliable and ultra-low delay. In addition, various emerging M2M applications have sparse traffic with a small amount of data to be delivered. The state-of-the-art OFDM technique has some limitations when addressing the aforementioned requirements at the same time. Meanwhile, numerous waveform alternatives, such as FBMC, GFDM, and UFMC, have been explored. They also have their own pros and cons due to their intrinsic waveform properties. Hence, it is the opportune moment to come up with modification/variations/combinations to the aforementioned techniques or a new waveform design for 5G systems and beyond. The aim of this Special Issue is to provide the latest research and advances in the field of waveform design for 5G systems and beyond
Recommended from our members
The optimization of multiple antenna broadband wireless communications. A study of propagation, space-time coding and spatial envelope correlation in Multiple Input, Multiple Output radio systems
This work concentrates on the application of diversity techniques and space time block coding for future mobile wireless communications.
The initial system analysis employs a space-time coded OFDM transmitter over a multipath Rayleigh channel, and a receiver which uses a selection combining diversity technique. The performance of this combined scenario is characterised in terms of the bit error rate and throughput. A novel four element QOSTBC scheme is introduced, it is created by reforming the detection matrix of the original QOSTBC scheme, for which an orthogonal channel matrix is derived. This results in a computationally less complex linear decoding scheme as compared with the original QOSTBC. Space time coding schemes for three, four and eight transmitters were also derived using a Hadamard matrix.
The practical optimization of multi-antenna networks is studied for realistic indoor and mixed propagation scenarios. The starting point is a detailed analysis of the throughput and field strength distributions for a commercial dual band 802.11n MIMO radio operating indoors in a variety of line of sight and non-line of sight scenarios. The physical model of the space is based on architectural schematics, and realistic propagation data for the construction materials. The modelling is then extended and generalized to a multi-storey indoor environment, and a large mixed site for indoor and outdoor channels based on the Bradford University campus.
The implications for the physical layer are also explored through the specification of antenna envelope correlation coefficients. Initially this is for an antenna module configuration with two independent antennas in close proximity. An operational method is proposed using the scattering parameters of the system and which incorporates the intrinsic power losses of the radiating elements. The method is extended to estimate the envelope correlation coefficient for any two elements in a general (N,N) MIMO antenna array. Three examples are presented to validate this technique, and very close agreement is shown to exist between this method and the full electromagnetic analysis using the far field antenna radiation patterns
Recommended from our members
Design and Linearization of Energy Efficiency Power Amplifier in Nonlinear OFDM Transmitter for LTE-5G Applications. Simulation and measurements of energy efficiency power amplifier in the presence of nonlinear OFDM transmitter system and digital predistortion based on Hammerstein-Wiener method
This research work has made an effort to understand a novel line of radio frequency
power amplifiers (RFPAs) that address initiatives for efficiency enhancement and
linearity compensation to harmonize the fifth generation (5G) campaign. The objective
is to enhance the performance of an orthogonal frequency division multiplexing-long
term evolution (OFDM-LTE) transmitter by reducing the nonlinear distortion of the
RFPA.
The first part of this work explores the design and implementation of 15.5 W class AB
RF power amplifier, adopting a balanced technique to stimulate efficiency enhancement
and redeeming exhibition of excessive power in the transmitter. Consequently, this work
goes beyond improving efficiency over a linear RF power amplifier design; in which a
comprehensive investigation on the fundamental and harmonic components of class F
RF power amplifier using a load-pull approach to realise an optimum load impedance
and the matching network is presented. The frequency bandwidth for both amplifiers was
allocated to operate in the 2.620-2.690 GHz of mobile LTE applications.
The second part explores the development of the behavioural model for the class AB
power amplifier. A particular novel, Hammerstein-Wiener based model is proposed to
describe the dynamic nonlinear behaviour of the power amplifier. The RF power amplifier
nonlinear distortion is approximated using a new linear parameter approximation
approach. The first and second-order Hammerstein-Wiener using the Normalised Least
Mean Square Error (NLMSE) algorithm is used with the aim of easing the complexity of
filtering process during linear memory cancellation. Moreover, an enhanced adaptive
Wiener model is proposed to explore the nonlinear memory effect in the system. The
proposed approach is able to balance between convergence speed and high-level
accuracy when compared with behavioural modelling algorithms that are more complex
in computation.
Finally, the adaptive predistorter technique is implemented and verified in the OFDM
transceiver test-bed. The results were compared against the computed one from
MATLAB simulation for OFDM and 5G modulation transmitters. The results have
confirmed the reliability of the model and the effectiveness of the proposed predistorter.FundacĂŁo para a CiĂȘncia e a Tecnologia, Portugal, under
European Unionâs Horizon 2020 research and innovation programme ... grant agreement H2020-MSCA-ITN- 2016 SECRET-722424
I also acknowledge the role of the National Space Research and Development Agency (NASRDA)
Sokoto State Government
Petroleum Technology Trust Fund (PTDF
Intelligent Circuits and Systems
ICICS-2020 is the third conference initiated by the School of Electronics and Electrical Engineering at Lovely Professional University that explored recent innovations of researchers working for the development of smart and green technologies in the fields of Energy, Electronics, Communications, Computers, and Control. ICICS provides innovators to identify new opportunities for the social and economic benefits of society.ă This conference bridges the gap between academics and R&D institutions, social visionaries, and experts from all strata of society to present their ongoing research activities and foster research relations between them. It provides opportunities for the exchange of new ideas, applications, and experiences in the field of smart technologies and finding global partners for future collaboration. The ICICS-2020 was conducted in two broad categories, Intelligent Circuits & Intelligent Systems and Emerging Technologies in Electrical Engineering
Spectrum Optimisation in Wireless Communication Systems: Technology Evaluation, System Design and Practical Implementation
Two key technology enablers for next generation networks are examined in this thesis, namely Cognitive Radio (CR) and Spectrally Efficient Frequency Division Multiplexing (SEFDM). The first part proposes the use of traffic prediction in CR systems to improve the Quality of Service (QoS) for CR users. A framework is presented which allows CR users to capture a frequency slot in an idle licensed channel occupied by primary users. This is achieved by using CR to sense and select target spectrum bands combined with traffic prediction to determine the optimum channel-sensing order. The latter part of this thesis considers the design, practical implementation and performance evaluation of SEFDM. The key challenge that arises in SEFDM is the self-created interference which complicates the design of receiver architectures. Previous work has focused on the development of sophisticated detection algorithms, however, these suffer from an impractical computational complexity. Consequently, the aim of this work is two-fold; first, to reduce the complexity of existing algorithms to make them better-suited for application in the real world; second, to develop hardware prototypes to assess the feasibility of employing SEFDM in practical systems. The impact of oversampling and fixed-point effects on the performance of SEFDM is initially determined, followed by the design and implementation of linear detection techniques using Field Programmable Gate Arrays (FPGAs). The performance of these FPGA based linear receivers is evaluated in terms of throughput, resource utilisation and Bit Error Rate (BER). Finally, variants of the Sphere Decoding (SD) algorithm are investigated to ameliorate the error performance of SEFDM systems with targeted reduction in complexity. The Fixed SD (FSD) algorithm is implemented on a Digital Signal Processor (DSP) to measure its computational complexity. Modified sorting and decomposition strategies are then applied to this FSD algorithm offering trade-offs between execution speed and BER
SystÚme d'annulation d'écho pour répéteur iso-fréquence : contribution à l'élaboration d'un répéteur numérique de nouvelle génération
On-frequency repeaters are a cost-effective solution to extend coverage and enhance wireless communications, especially in shadow areas. However, coupling between the receiving antenna and the transmitting antenna, called radio frequency echo, increases modulation errors and creates oscillations in the system when the echo power is high. According to the communication standards, extremely weak echoes decrease the transmission rate, while strong echoes damage electroni ccircuits because of power peaks. This thesis aims at characterizing the echo phenomenon under different modulations, and proposing an optimized solution directly integrated to industry. We have turned to digital solutions especially the adaptive because of their high convergence rate and their simplicity to be implemented. The programmable circuits are chosen for their attractive price and their flexibility. When implementing echo cancellation solution, we proposed several reliable solutions, showing that digital processing is much more beneficial. For this reason, digital solutions are generalized, and the new generation of repeaters is fully digital.Le dĂ©ploiement des rĂ©pĂ©teurs iso-frĂ©quence est une solution Ă©conomique pour Ă©tendre la couverture dâun Ă©metteur principal aux zones dâombre. Cependant, ce mode de dĂ©ploiement fait apparaĂźtre le phĂ©nomĂšne des Ă©chos radio-frĂ©quence entre antennes dâĂ©mission et de rĂ©ception du rĂ©pĂ©teur. Selon les standards, un Ă©cho aussi faible soit-il rĂ©duit le dĂ©bit de la liaison radio, tandis quâun Ă©cho fort fait courir au rĂ©pĂ©teur le risque dâendommager ses circuits Ă©lectroniques, ces risques sont dĂ»s aux ondulations de puissance crĂ©Ă©es par les Ă©chos. Lâobjectif de cette thĂšse Ă caractĂšre industriel est dâĂ©tudier ce phĂ©nomĂšne naturel en considĂ©rant des signaux provenant de diffĂ©rents standards des tĂ©lĂ©communications. Cette Ă©tude permet une caractĂ©risation des Ă©chos radio-frĂ©quence pour mieux sâorienter vers une solution optimisĂ©e et industriellement rĂ©alisable.Nous nous sommes orientĂ©s vers la solution du traitement du signal avancĂ© en favorisant le filtrage adaptatif pour sa rapiditĂ© de convergence et sa simplicitĂ© relative dâimplantation matĂ©rielle. Les circuits reconfigurables sont retenus pour leur prix et leur souplesse. Lâimplantation des solutions est effectuĂ©e en virgule fixe afin de satisfaire les exigences de rĂ©activitĂ©. Durant la mise en oeuvre de la solution anti-Ă©cho, nous avons proposĂ© une multitude de solutions numĂ©riques souples et fiables. Ă partir de ce constat, notre partenaire industriel a dĂ©cidĂ© de gĂ©nĂ©raliser ce mode de traitement par le dĂ©veloppement, la fabrication et la commercialisation de rĂ©pĂ©teurs de nouvelle gĂ©nĂ©ration entiĂšrement numĂ©riques
Semi-automatic liquid filling system using NodeMCU as an integrated Iot Learning tool
Computer programming and IoT are the key skills required in Industrial
Revolution 4.0 (IR4.0). The industry demand is very high and therefore related
students in this field should grasp adequate knowledge and skill in college or university
prior to employment. However, learning technology related subject without
applying it to an actual hardware can pose difficulty to relate the theoretical knowledge
to problems in real application. It is proven that learning through hands-on
activities is more effective and promotes deeper understanding of the subject matter
(He et al. in Integrating Internet of Things (IoT) into STEM undergraduate education:
Case study of a modern technology infused courseware for embedded system
course. Erie, PA, USA, pp 1â9 (2016)). Thus, to fulfill the learning requirement, an
integrated learning tool that combines learning of computer programming and IoT
control for an industrial liquid filling system model is developed and tested. The
integrated learning tool uses NodeMCU, Blynk app and smartphone to enable the
IoT application. The system set-up is pre-designed for semi-automation liquid filling
process to enhance hands-on learning experience but can be easily programmed for
full automation. Overall, it is a user and cost friendly learning tool that can be developed
by academic staff to aid learning of IoT and computer programming in related
education levels and field
Radio Communications
In the last decades the restless evolution of information and communication technologies (ICT) brought to a deep transformation of our habits. The growth of the Internet and the advances in hardware and software implementations modiïŹed our way to communicate and to share information. In this book, an overview of the major issues faced today by researchers in the ïŹeld of radio communications is given through 35 high quality chapters written by specialists working in universities and research centers all over the world. Various aspects will be deeply discussed: channel modeling, beamforming, multiple antennas, cooperative networks, opportunistic scheduling, advanced admission control, handover management, systems performance assessment, routing issues in mobility conditions, localization, web security. Advanced techniques for the radio resource management will be discussed both in single and multiple radio technologies; either in infrastructure, mesh or ad hoc networks