Rim Barrak | Aaa - Academia.edu (original) (raw)

Papers by Rim Barrak

2016 5th International Conference on Multimedia Computing and Systems (ICMCS), 2016

Varactor-based tunable bandpass filters are challenging solutions for next generation mobile phon... more Varactor-based tunable bandpass filters are challenging solutions for next generation mobile phones that allow using one RF front-end for multiple applications. However, these solutions suffer from varactors non-linear effects that may affect signal quality and may introduce important distortions. This paper presents a thorough study of varactors nonlinear effects and some solutions for their cancellation. These solutions are applied in tunable Dual Behavior Resonator (DBR) bandpass filter to reduce non-linear distortions. S-parameter and Harmonic balance simulations were conducted to study and compare the performances of the solutions reported in the literature.

While GPS high quality products supplied by leading global components (Motorola, Analog Devices, ... more While GPS high quality products supplied by leading global components (Motorola, Analog Devices, Sirf, Maxim, Qualcomm ...) are available, many research works are carried out in order to improve sensitivity, response time, dynamics, accuracy, size and power consumption. In addition, continuity of the positioning service between outdoor and indoor appears as a must for the next years. Most of the receivers are limited to a single standard and do not offer positioning services in areas where satellites are not available. Although many techniques have been proposed these last ten years, ranging from High-Sensitivity GNSS (Global Navigation Satellite System) to sensor networks, through Assisted-GNSS or WLAN based approaches, no ultimate solution seems yet to provide the answer to the indoor positioning problem, probably crucial to Location Based Services. In order to enhance receiver performance in harsh environments where significant multipath problems are present and ensure continuity...

2019 15th International Wireless Communications & Mobile Computing Conference (IWCMC), 2019

The use of smart antennas with fully adaptive properties is a promising solution for next generat... more The use of smart antennas with fully adaptive properties is a promising solution for next generation wireless networks aiming to optimize the performance of radio channel and reduce interference. Reconfigurable antennas are desirable in many applications due to their ability to change their pattern, polarization and resonance frequency dynamically. One of the reconfigurable techniques is to use phase shifter loaded with Positive Intrinsic Negative (PIN) diode. In this paper, we propose the design of a switched-line phase shifter at 28 GHz millimeter wave band based on microstrip transmission lines and PIN diodes. The design was achieved using Ansys High-Frequency Structure Simulator (HFSS). A phase shift of 145° ± 7° along the band 24–29 GHz is obtained with an insertion loss below 5dB and a return loss better than 14dB. This proposed circuit can be used in the design of reconfigurable antenna arrays in the mm-wave band.

2016 5th International Conference on Multimedia Computing and Systems (ICMCS), 2016

Next generation Optical Networks become a topical issue that requires much researcher's inter... more Next generation Optical Networks become a topical issue that requires much researcher's interest especially the improvement of last miles of the optical networks (access network). Radio over fiber technology fulfills with heterodyne optical networks needs since it answers to wideband applications requirements and meets high capacities networks. The association of RoF systems and futuristic optical access networks provides flexible high capacities networks. In this paper, we propose a RoF system architecture able to support muli-service (WiFi, WiMAX and mm-wave), multi-band (2.4, 5.2 and 60 GHz), multi-modulation schemas (BPSK, QPSK and 16QAM) and multi-data rates up to 5 Gbps. The selected transmission technique and service will depend on cell capacities, applications requirements and mobile user concentration. To validate the RoF system performances, we have simulated mm-wave Error Vector Magnitude (EVM) and constellation for different services.

2017 18th International Conference on Sciences and Techniques of Automatic Control and Computer Engineering (STA), 2017

The purpose of the paper is to investigate the design of rectangular patch antenna arrays fed by ... more The purpose of the paper is to investigate the design of rectangular patch antenna arrays fed by miscrostrip and coaxial lines at 28 GHz for future 5G applications. Our objective is to design a four element antenna array with a bandwidth higher than 1 GHz and a maximum radiation gain. The performances of the rectangular 4∗1 and 2∗2 patch antenna arrays designed on Rogers RT/Duroid 5880 substrate were optimized and the simulation results reveal that the performance of 4∗1 antenna array fed by microstrip line is better than 2∗2 antenna array fed by coaxial cable. We obtained for the topology of 4∗1 rectangular patch array antenna a bandwidth of 2.15 GHz and 1.3 GHz respectively with almost similar gains of the order of 13.3 dBi.

2016 5th International Conference on Multimedia Computing and Systems (ICMCS), 2016

This paper presents a reconfigurable decimation filter architecture for reconfigurable multiband ... more This paper presents a reconfigurable decimation filter architecture for reconfigurable multiband GNSS receivers. The proposed filter architecture is designed for a reconfigurable GNSS subsampling receiver, where the sampling process is performed at the Analog to Digital Converter. As the selected sampling rates are much higher than the Nyquist rate, a decimation stage is required to speed up GNSS digital processing, mainly the acquisition, the tracking and the navigation. The proposed reconfigurable filter performs decimation in two stages; the first one is a Cascade Integrator Combs (CIC). This filter allows reducing the sampling rate to twice the required GNSS signals bandwidth. The second stage composed of compensation filter to achieve wide broadband compensation of the CIC filter and to perform decimation to the Nyquist frequency. In this paper, Decimation filter specification for multiband GNSS signals is first derived. Then, the parameters of CIC and FIR filters are investiga...

2018 6th International Conference on Multimedia Computing and Systems (ICMCS), 2018

In Wireless GNSS navigation, there is a high demand for a potential multi-standard receiver capab... more In Wireless GNSS navigation, there is a high demand for a potential multi-standard receiver capable to improve the performance and decrease the complexity. The key solution to achieve a better accuracy position is to integrate new structure based on RF sampling (RFS). In this paper, this novel structure is introduced, analyzed and implemented using discrete components. Notably, the proposed architecture has the potential to be reconfigured in a sample, flexible and cost-effective manner. To evaluate the operational and the functionality of the designed receiver, experimental tests are accomplished. Three kinds of signals are expound 1) recorded signals reproducing the original ones are played. It can be arranged in such a way that signal is recorded on a standalone device, such as the one by Spirent system 2) simulated signals arranged by the Rohde & Schwarz systems including PRN code of satellites (4,10,31) 3) using a real constellation of GPS L1 while testing signals from GPS ante...

2016 5th International Conference on Multimedia Computing and Systems (ICMCS), 2016

Global Navigation Satellite System (GNSS) is widely used around the world. It includes services p... more Global Navigation Satellite System (GNSS) is widely used around the world. It includes services provided by GPS, GLONASS, GALILEO and BEIDOU. GNSS-based applications use GNSS receivers to collect position, velocity and time information. Thus, the implementation of a multistandard GNSS receiver brings enormous benefits to consumers of wireless services. Besides, developing a reconfigurable receiver allows reducing significantly its power consumption.

2020 22nd International Conference on Transparent Optical Networks (ICTON), 2020

Radio-over-Fiber in millimeter wave band is the promising technology to meet challenges of the 5G... more Radio-over-Fiber in millimeter wave band is the promising technology to meet challenges of the 5G generation to raise the user capacity and to accommodate a large number of user channels at considerably high data rates by using a massive MIMO and high antenna gain. In this paper, we propose a novel stacked patch antenna array working at 26 GHz band for future 5G applications using uniplanar Electromagnetic Band Gap (EBG) structure to suppress the surface wave. It has been demonstrated that the surface waves were considerably reduced. The proposed antenna array shows a bandwidth of 1.42 GHz ranging from 24.22 GHz to 25.64 GHz and a gain up to 8 dBi at 25.4 GHz. The proposed design holds a great potential application for deployment in 5G generation.

Mm-wave bands have been explored for high-capacity wireless systems. Despite the fact that optica... more Mm-wave bands have been explored for high-capacity wireless systems. Despite the fact that optical technologies can contribute to generate and transport such signals, the electrical front-ends for the mm-wave transceivers are still overlooked. Radio over fiber (RoF) and reconfigurable antenna technologies have been used to achieve the requirements of modern telecommunications networks. Allowing the convergence of wired and wireless services, the RoF technology can satisfy the use of the huge bandwidth offered by optical communications systems with the mobility and flexibility provided by wireless systems. In this paper, we aim to design an original wideband differential fed patch antenna for mm-wave radio over fiber communications with more than 4 GHz bandwidth and 5 dBi gain at 26 GHz band. The proposed circuit is the elementary cell of a reconfigurable antenna array that will be designed for the future generation of RoF systems.

Global Navigation Satellite Systems (GNSS) are widespread around the world providing users with s... more Global Navigation Satellite Systems (GNSS) are widespread around the world providing users with several services from GPS, GLONASS, GALILEO and BEIDOU satellites. Localization and positioning applications use GNSS receivers to find navigation position. Thus, the implementation of a reconfigurable multi-constellation receiver should be highlighted.This paper presents a reconfigurable GNSS receiver setup based on the sub-sampling architecture. First, the evaluation of the sampling frequencies for different scenarios is performed in order to include various standards at the same time. Then, experimental assessment to detect the visible satellites while handling GPS and GLONASS signals are successfully established and it validates the proposed multi standard GNSS sub-sampling receiver operation for GPS and GLONASS.

2018 International Conference on Smart Communications and Networking (SmartNets)

We have developed a multi-standard GNSS (Global Navigation Satellite System) receiver including t... more We have developed a multi-standard GNSS (Global Navigation Satellite System) receiver including the simultaneous detection of the four current constellations: GPS, GLONASS, Galileo and Beidu. The technique used is sub-sampling, which simplifies the receiver architecture. A special feature of our implementation is that the "indoor" aspect is already taken into account at the design stage. The latter is further considered by the use of pseudo-satellites ("pseudolites") of particular architecture, the "Grin-Locs". In our case, we have adapted the frequency bands of the various constellations in order to include the associated indoor constraints in our sub-sampling design.This article presents the problem of indoor using Grin-Locs and the performances obtained with our multi-standard sub-sampling receiver in phase measurements of signals for indoor positioning.

2019 IEEE 19th Mediterranean Microwave Symposium (MMS)

In this work, a novel stacked patch antenna array for future 5G applications is proposed. Initial... more In this work, a novel stacked patch antenna array for future 5G applications is proposed. Initially, a single stacked patch antenna is designed to operate at 26 GHz band while maintaining good performances of bandwidth and gain. Better performances are obtained by stacking the superstrate layer above the antenna structure, thereby improving the gain and the bandwidth. The proposed antenna covers the frequency band from 23.02 GHz to 26.12 GHz resulting in a wide bandwidth with a compact size of 13*12 mm2. Performances of the antenna are improved by incorporating an array of 2 identical elements based on the single designed patch antenna, resulting in a higher gain. The proposed array consists of 2 elements using 0.65 mm AR1000 substrate. The two element antenna array shows a good performance in terms of bandwidth (1.7 GHz) and gain reaching 12 dBi with a size of 13*25mm2. The proposed designs are a great potential application for deployment in 5G generation.

Radioengineering

A new topology for a multiband filter suitable for multistandard and multiband mobile terminals i... more A new topology for a multiband filter suitable for multistandard and multiband mobile terminals is proposed. This filter named MultiCrossed Open Stubs (MCOS) is based on the wideband Quarter-Wave Short Circuited Stubs (QWSCS) topology and consists of open stubs connected together with the main transmission line via a multicross junction. This technique allows division the wide bandpass response into several subbands by means of open stub transmission zeros. Full synthesis of the MCOS filter using ABCD matrices and its application to GSM, GPS, UMTS, LTE, and Wi-Fi standards using FR4 microstrip technology are presented. Scattering (S) parameters simulations and measurements show good agreement according to standard specifications in terms of center frequencies and bandwidths. The achievable return losses for all bands are higher than 10 dB, and transmission losses are between 3.9 dB and 6 dB. The proposed multiband filter topology is well suited for the implementation of reconfigurable multiband filters.

Radioengineering

In this paper, we investigate a scalable Radio over Fiber (RoF) system compliant to 5G fronthauli... more In this paper, we investigate a scalable Radio over Fiber (RoF) system compliant to 5G fronthauling requirements. The proposed RoF architecture is able to adjust the network resources and capacities to satisfy user demands in terms of service, data rate and bandwidth. The flexibility and the reconfigurability of the proposed topology are provided through the inclusion of flexible network nodes which are at the Central Office (CO), the Remote Node (RN) and the Remote Access Unit (RAU). The centralized management of the RoF system based on a Software Defined Networking (SDN) enables the monitoring of the overhaul RoF system and the reconfiguration of network nodes parameters. The proposed RoF system architecture is designed to support multi-standard operation and mm-wave services. We investigated multi-service operation assuming high speed mm-wave service at 60 GHz besides to conventional wireless services such as WiFi and WiMax. The introduced system is able to operate for different RF bands (2.4, 5.2 and 60 GHz) with various modulation schemas such as BPSK, QPSK, 16QAM and 64QAM, that may be associated to Orthogonal Frequency-Division Multiplexing (OFDM) and multidata rates up to 5 Gbps. To validate the RoF system performances, we have considered the Error Vector Magnitude (EVM) and service constellation as figures of merit at the End User (EU). The simulated results testify the architecture viability.

AEU - International Journal of Electronics and Communications

Abstract This paper presents the design of a tunable RF filter dedicated for multistandard operat... more Abstract This paper presents the design of a tunable RF filter dedicated for multistandard operation in Software Defined Radio (SDR) receivers. This filter is based on the Dual-Behaviour Resonators (DBR) topology realized in microstrip technology with PTFE substrate and using SMV1405 varactors as tuning elements. It provides the independent control of its center frequency and bandwidth relative to the radio standards UMTS, Wi-Fi and LTE (Band N°7). The center frequency ranges from 2.142 to 2.65 GHz and the required bandwidth varies from 86 to 108 MHz. S-parameters simulations and measurements with non-linearity study are provided to evaluate the performance of the designed filter. A very good agreement between simulations and measurements is obtained and the designed filter shows acceptable performances in terms of insertion and return losses which are less than 6 dB and more than 14 dB, respectively for all bands. Moreover, linear properties regarding receiver requirements with a minimum 1-dB compression point (P1dB) of 11.4 dBm and a minimum third order intercept point (IP3) of 21.2 dBm are satisfying.

IEEE Transactions on Circuits and Systems II: Express Briefs

A novel reconfigurable dual-bandpass filter with independently controlled center frequencies and ... more A novel reconfigurable dual-bandpass filter with independently controlled center frequencies and fixed bandwidths is presented. It was designed to be integrated as a radio frequency anti-aliasing filter in a reconfigurable multi-bandpass sampling global navigation satellite system (GNSS) receiver. The center frequency tuning ranges are 1190–1210 MHz and 1560–1590 MHz in the lower and the upper L-bands, respectively, with a fixed bandwidths of 35 MHz. Varactor tuning technology associated with open loop stub loaded resonator microstrip topology were investigated to achieve these goals. The proposed dual-bandpass filter design showed the agility to independently control the center frequencies in the two L-bands and to deactivate one of the passbands. Furthermore, it shows enough flexibility to adapt to the deployment of new GNSS standards specifications. It exhibits on all the tuning ranges an insertion and a return losses of less than 4.5 dB and more than 10 dB, respectively.

2016 11th International Design & Test Symposium (IDT), 2016

The nonlinearity is an important factor that limit the improvement of the overall performance of ... more The nonlinearity is an important factor that limit the improvement of the overall performance of a GNSS receiver. In order to prove the subsampling GNSS receiver performance for a weak desired system, a simple method is to characterize the derivation in nonlinearity and to quantify the impact on the wanted signal.

2016 18th International Conference on Transparent Optical Networks (ICTON), 2016

The development of reconfigurable and high throughput architectures is the utmost target for rese... more The development of reconfigurable and high throughput architectures is the utmost target for researchers in the field of Radio over Fiber (RoF). In this paper, we developed a cognitive radio over fiber system lined up with Software Defined Networking owing to improve the quality of transport using a pre-equalization technique. The pre-equalization technique is based on Least Mean Square (LMS) algorithm. It is used to compensate the optical link performance degradation in the RoF system. The simulation results of the overall Bit Error Rate (BER) and the Q factor attest of high system performance improvement.

2016 IEEE Wireless Communications and Networking Conference Workshops (WCNCW), 2016

In this paper a novel cognitive Radio over Fiber (RoF) system lined up with Software Defined Netw... more In this paper a novel cognitive Radio over Fiber (RoF) system lined up with Software Defined Networking (SDN) requirements is presented. First, the SDN paradigm for the proposed hybrid RoF system with centralized topology is developed. Then, cognitive process enabling self-aware RoF network is outlined. The goal is to allow traffic and network supervision and enable whole system intelligent management. In particular, we have defined the optical and radio sensing parameters, the required network controllers and the adaptation parameters. To highlight the impact of cognitive processing and the ability of the control plane to enhance the RoF network performances, some test scenarios are investigated.