A New Downlink Scheduling Algorithm Proposed for Real Time Traffic in LTE System

The Third Generation Partnership Project (3GPP) has developed a new cellular standard based packet switching allowing high data rate, 100 Mbps in Downlink and 50 Mbps in Uplink, and having the flexibility to be used in different bandwidths ranging from 1.4 MHz up to 20 MHz, this standard is termed LTE (Long Term Evolution). Radio Resource Management (RRM) procedure is one of the key design roles for improving LTE system performance, Packet scheduling is one of the RRM mechanisms and it is responsible for radio resources allocation, However, Scheduling algorithms are not defined in 3GPP specifications. Therefore, it gets a track interests for researchers. In this paper we proposed a new LTE scheduling algorithm and we compared its performances with other well known algorithms such as Proportional Fairness (PF), Modified Largest Weighted Delay First (MLWDF), and Exponential Proportional Fairness (EXPPF) in downlink direction. The simulation results shows that the proposed scheduler satisfies the quality of service (QoS) requirements of the real-time traffic in terms of packet loss ratio (PLR), average throughput and packet delay. This paper also discusses the key issues of scheduling algorithms to be considered in future traffic requirements

Automatic target detection and localization using ultra-wideband radar

The pulse ultra-wide band (UWB) radar consists of switching of energy of very short duration in an ultra-broadband emission chain, and the UWB signal emitted is an ultrashort pulse, of the order of nanoseconds, without a carrier. These systems can indicate the presence and distances of a distant object, call a target, and determine its size, shape, speed, and trajectory. In this paper, we present a UWB radar system allowing the detection of the presence of a target and its localization in a road environment based on the principle of correlation of the reflected signal with the reference and the determination of its correlation peak

Etude et conception d’un quadrupleur de fréquence en technologie MMIC pour des applications à 60 GHz

Dans ce papier, un circuit multiplicateur de fréquence par 4 est proposé. Ce quadrupleur fonctionne dans la bande millimétrique [56-64 GHz], il est conçu en technologie MMIC (Monolithic Microwave Integrated Circuit) en utilisant le procédé technologique PH15 de la fonderie UMS. Le circuit quadrupleur de fréquence sera utilisé pour générer des fréquences porteuses appartenant à la bande [56-64 GHZ] permettant de réaliser la démodulation du signal RF d’une liaison de communication sans fil en bande millimétrique. Ce quadrupleur fera partie du bloc récepteur d’une liaison de communication sans fil à très haut débit en bande millimétrique à 60 GHz

Etude d’une liaison ULB de type MB-OOK

L’ultra Large Bande (ULB) est une technologie de communication sans fil qui consiste à transmettre (télécommunications) ou à recueillir (radar) des données en utilisant des signaux impulsionnels de courte durée et ayant donc un large spectre de fréquences. Elle a suscité beaucoup d’intérêt en radar et télécommunications. Elle semble être un candidat viable en particulier pour les communications indoor offrant des débits binaires très élevés (> 100 Mbits/s) pour les courtes distances (10 à 50 m). Dans le domaine des transmissions ULB, deux grandes familles de formes d’onde sont en concurrence. Il s’agit d’une part des formes d’onde impulsionnelles, et d’autre part des formes d’onde multi-porteuses (MBOA : Multiband-OFDM Alliance). Une troisième forme d’onde a été proposée récemment par Mitsubishi, c’est la solution multi-bande impulsionnelle : ULB MB-OOK, qui regroupe les avantages des deux formes d’onde. Dans cet article, nous présentons les résultats de simulation et de mesure d’une liaison ULB MB-OOK dans le domaine temporel en mettant en évidence l’influence des différentes parties de l’architecture sur la dynamique du signal ULB le long de la liaison. Nous présentons aussi nos travaux de développement d’un circuit générateur d’impulsions monocycles gaussiennes, qui est l’un des éléments clés d’une liaison ULB MBOOK

Etude de l'impact de différents algorithmes d'ordonnancement pour les femto-cellules pour des trafics temps réel dans le réseau 5G

Le déploiement des femto-cellules dans les systèmes de cinquième génération (5G), s’avère nécessaire grâce à leurs avantages en termes du nombre d'utilisateurs supporté, et de la réduction de la consommation d'énergie, permettant ainsi de répondre aux exigences des réseaux 5G. Or que l’allocation des ressources et la gestion du traffic, tout en maintenant la qualité de service (QoS) ; constituent un défi majeur en terme d’équité et de débit perçu au niveau du terminal.    Dans ce papier, un certain nombre d'algorithmes d'ordonnancement prévus d’être utilisés en 5G, à savoir l’algorithme Proportional Fair (PF), l’algorithme Exponential Proportional Fair (EXP/PF) et l’algorithme Maximum Largest Weighted Delay First (MLWDF) sont étudiés et comparés en matière d’équité (Fairness Index), de débit utile (Goodput) et d’efficacité spectrale, au niveau des femto-cellules en sens descendant

A 5G mm-wave compact voltage-controlled oscillator in 0.25 µm pHEMT technology

A 5G mm-wave monolithic microwave integrated circuit (MMIC) voltage-controlled oscillator (VCO) is presented in this paper. It is designed on GaAs substrate and with 0.25 µm-pHEMT technology from UMS foundry and it is based on pHEMT varactors in order to achieve a very small chip size. A 0dBm-output power over the entire tuning range from 27.67 GHz to 28.91 GHz, a phase noise of -96.274 dBc/Hz and -116.24 dBc/Hz at 1 and 10 MHz offset frequency from the carrier respectively are obtained on simulation. A power consumption of 111 mW is obtained for a chip size of 0.268 mm2. According to our knowledge, this circuit occupies the smallest surface area compared to pHEMTs oscillators published in the literature

High rejection self-oscillating up-conversion mixer for fifth-generation communications

This paper presents the design of a pseudomorphic high electron mobility transistor (pHEMT) self-oscillating mixer (SOM) for millimeter wave wireless communication systems. The 180° out-of-phase technique is chosen to both improve the desired lower sideband (LSB) signal and to achieve a satisfactory rejection of the unwanted signals (LO, USB and IF). This SOM is designed on the PH15 process of UMS foundry which is based on 0.15 µm GaAs pHEMT. The signal is up-converted from 2 GHz-IF frequency to 26 GHz-LSB frequency, using an autogenerated 28 GHz-LO signal. Simulations were performed using the advanced design system (ADS) workflow. They show 6.4 dB conversion gain and a signal rejection rate of 29.7 dB for the unwanted USB signal. the chip size is 3.6 mm2

28 GHz balanced pHEMT VCO with low phase noise and high output power performance for 5G mm-Wave systems

This paper presents the study and design of a balanced voltage controlled oscillator VCO for 5G wireless communication systems. This circuit is designed in monolithic microwave integrated circuit (MMIC) technology using PH15 process from UMS foundry. The VCO ensures an adequate tuning range by a single-ended pHEMT varactors configuration. The simulation results show that this circuit delivers a sinusoidal signal of output power around 9 dBm with a second harmonic rejection between 25.87 and 33.83 dB, the oscillation frequency varies between 26.46 and 28.90 GHz, the phase noise is -113.155 and -133.167 dBc/Hz respectively at 1 MHz and 10 MHz offset and the Figure of Merit is -181.06 dBc/Hz. The power consumed by the VCO is 122 mW. The oscillator layout with bias and RF output pads occupies an area of 0.515 mm2

New microstrip patch antenna array design at 28 GHz millimeter-wave for fifth-generation application

This paper presents a study and an array design consisting of two microstrip patch antennas connected in series in a 2×1 form. This antenna provides better performance for the fifth-generation (5G) wireless communication system. The microstrip line feeding technique realizes the design of this antenna. This feed offers the best bandwidth, is easy to model, and has low spurious radiation. The distance between the feed line and the patch can adapt to the antenna’s impedance. In addition, the antenna array proposed in this paper is designed and simulated using the high frequency structure simulator (HFSS) simulation software at the operating frequency of 28 GHz for the 5G band. The support material used is Rogers RT/duroid® 5880, with relative permittivity of 2.2, a thickness of h=0.5 mm, and a loss tangent of 0.0009. The simulation results obtained in this research paper are as: reflection coefficient: -35.91 dB, standing wave ratio (SWR): 1.032, bandwidth: 1.43 GHz, gain: 9.42 dB, directivity: 9.47 dB, radiated power: 29.94 dBm, accepted the power: 29.99 dBm, radiation efficiency: 29.95, efficiency: 99.83%. This proposed antenna array has achieved better performance than other antenna arrays recently published in scientific journals regarding bandwidth, beam gain, reflection coefficient, SWR, radiated power, accepted power, and efficiency. Therefore, this antenna array will likely become an important competitor for many uses within the 5G wireless applications

A comparison between common-source and cascode topologies for V-band millimeter-wave MMIC Low Noise Amplifier design

In this paper, a three-stage cascode LNA and a three-stage common source LNA are presented. A comparison in terms of noise figure and gain between the two designed three-stage MMIC common source and cascode LNAs is discussed. This LNAs will be used as a part of a WPAN (Wirless Personal Area Network) receiver in the millimeter-wave band at 60 GHz. These low noise amplifiers are designed according to the MMIC technology (Monolithic Microwave Integrated Circuit) in PH15 process from UMS foundry and uses a 0.15 μm GaAs PHEMT (Pseudomorphic High Electron Mobility Transistor). The three-stage cascode LNA shows better performances compared to the three-stage common source LNA. The proposed three-stage cascode LNA exhibits a very low noise figure which is equal to 1dB and a high gain which is about 23 dB. An input return loss of -6.61 dB and an output return loss of -11.26 dB are also achieved by this LNA