scholarly journals Frequency Offset Tolerant Synchronization Signal Design in NB-IoT

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 4077 ◽  
Author(s):  
Jun Zou ◽  
Chen Xu
Keyword(s):  
Communication Systems ◽  
Low Cost ◽  
Frequency Offset ◽  
Wireless Communication Systems ◽  
Signal Design ◽  
Timing Error ◽  
Signal Structure ◽  
Synchronization Signal ◽  
Large Frequency ◽  
Suitable Sequence

Timing detection is the first step and very important in wireless communication systems. Timing detection performance is usually affected by the frequency offset. Therefore, it is a challenge to design the synchronization signal in massive narrowband Internet of Things (NB-IoT) scenarios where the frequency offset is usually large due to the low cost requirement. In this paper, we firstly proposed a new general synchronization signal structure with a couple of sequences which are conjugated to remove the potential timing error that arises from large frequency offset. Then, we analyze the suitable sequence for our proposed synchronization signal structure and discuss a Zadoff–Chu (ZC) sequence with root 1 as an example. Finally, the simulation results demonstrate that our proposed synchronization signal can work well when the frequency offset is large. It means that our proposed synchronization signal design is very suitable for the massive NB-IoT.

scholarly journals Physical-Layer Security Improvement with Reconfigurable Intelligent Surfaces for 6G Wireless Communication Systems

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1439
Author(s):  
Janghyuk Youn ◽  
Woong Son ◽  
Bang Chul Jung
Keyword(s):  
Wireless Communication ◽  
Physical Layer Security ◽  
Communication Systems ◽  
Low Cost ◽  
Physical Layer ◽  
Base Station ◽  
Wireless Communication Systems ◽  
Secrecy Rate ◽  
Pilot Signal ◽  
Time Division

Recently, reconfigurable intelligent surfaces (RISs) have received much interest from both academia and industry due to their flexibility and cost-effectiveness in adjusting the phase and amplitude of wireless signals with low-cost passive reflecting elements. In particular, many RIS-aided techniques have been proposed to improve both data rate and energy efficiency for 6G wireless communication systems. In this paper, we propose a novel RIS-based channel randomization (RCR) technique for improving physical-layer security (PLS) for a time-division duplex (TDD) downlink cellular wire-tap network which consists of a single base station (BS) with multiple antennas, multiple legitimate pieces of user equipment (UE), multiple eavesdroppers (EVEs), and multiple RISs. We assume that only a line-of-sight (LOS) channel exists among the BS, the RISs, and the UE due to propagation characteristics of tera-hertz (THz) spectrum bands that may be used in 6G wireless communication systems. In the proposed technique, each RIS first pseudo-randomly generates multiple reflection matrices and utilizes them for both pilot signal duration (PSD) in uplink and data transmission duration (DTD) in downlink. Then, the BS estimates wireless channels of UE with reflection matrices of all RISs and selects the UE that has the best secrecy rate for each reflection matrix generated. It is shown herein that the proposed technique outperforms the conventional techniques in terms of achievable secrecy rates.

scholarly journals A 300-GHz low-cost high-gain fully metallic Fabry–Perot cavity antenna for 6G terahertz wireless communications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Basem Aqlan ◽  
Mohamed Himdi ◽  
Hamsakutty Vettikalladi ◽  
Laurent Le-Coq
Keyword(s):  
Communication Systems ◽  
Low Cost ◽  
Frequency Selective Surface ◽  
High Gain ◽  
Wireless Communication Systems ◽  
Beam Radiation ◽  
Compact Size ◽  
Fabry Perot ◽  
Operating Bandwidth ◽  
Polarization Level

AbstractA low-cost, compact, and high gain Fabry–Perot cavity (FPC) antenna which operates at 300 GHz is presented. The antenna is fabricated using laser-cutting brass technology. The proposed antenna consists of seven metallic layers; a ground layer, an integrated stepped horn element (three-layers), a coupling layer, a cavity layer, and an aperture-frequency selective surface (FSS) layer. The proposed aperture-FSS function acts as a partially reflective surface, contributing to a directive beam radiation. For verification, the proposed sub-terahertz (THz) FPC antenna prototype was developed, fabricated, and measured. The proposed antenna has a measured reflection coefficient below − 10 dB from 282 to 304 GHz with a bandwidth of 22 GHz. The maximum measured gain observed is 17.7 dBi at 289 GHz, and the gain is higher than 14.4 dBi from 285 to 310 GHz. The measured radiation pattern shows a highly directive pattern with a cross-polarization level below − 25 dB over the whole band in all cut planes, which confirms with the simulation results. The proposed antenna has a compact size, low fabrication cost, high gain, and wide operating bandwidth. The total height of the antenna is 1.24 $${\lambda }_{0}$$ λ 0 ($${\lambda }_{0}$$ λ 0 at the design frequency, 300 GHz) , with a size of 2.6 mm × 2.6 mm. The proposed sub-THz waveguide-fed FPC antenna is suitable for 6G wireless communication systems.

Reconfigurable Antenna

2016 ◽  
pp. 237-263
Author(s):  
Mohamad Kamal A Rahim ◽  
Huda A. A. Majid ◽  
Mohamad Rijal Hamid
Keyword(s):  
Communication Systems ◽  
Low Cost ◽  
Wireless Systems ◽  
Reconfigurable Antennas ◽  
Effective Length ◽  
Slot Antenna ◽  
Wireless Communication Systems ◽  
Reconfigurable Antenna ◽  
5 Ghz ◽  
Narrow Bands

Reconfigurable antennas have attracted a lot of attention especially in future wireless communication systems. Superior features such as reconfigurable capability, low cost, multi-purpose functions and size miniaturization have given reconfigurable antennas advantage to be integrated into a wireless systems. In this chapter, two types of reconfigurable antennas are discussed. First, frequency reconfigurable narrowband microstrip slot antenna (FRSA) is presented. The proposed antenna is designed to operate at six reconfigurable frequency bands from 2 GHz to 5 GHz with bidirectional radiation pattern. The second antenna design is frequency reconfigurable narrowband patch-slot antenna (FRPSA) is presented. The antenna is a combination of a microstrip patch and slot antenna. Nine different narrow bands are produced by tuning the effective length of the slot. The performances of the antenna in term of simulated and measured results are presented. In conclusion, good agreement between the simulated and measured results has been attained.

scholarly journals Beampattern analysis of frequency diverse array radar: a review

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Zeeshan Ahmad ◽  
Meng Chen ◽  
Shu-Di Bao
Keyword(s):  
Communication Systems ◽  
Essential Feature ◽  
Beam Steering ◽  
Frequency Offset ◽  
Wireless Communication Systems ◽  
Electronic Beam Steering ◽  
Potential Applications ◽  
Frequency Offsets ◽  
Frequency Diverse Array ◽  
Beampattern Synthesis

AbstractElectronic beam steering is an essential feature of state-of-the-art radar systems. Conventional phased array (PA) radars with fixed carrier frequencies are well-known for electronically steering their beam with high directivity. However, the resulting beampattern is angle-dependent but range-independent. Recently, a new electronic beam steering concept, referred to as frequency diverse array (FDA) radar, has attracted increasing attention due to its unique range-angle dependent beampattern. More importantly, the FDA radar employs a small frequency increment across the array elements to achieve beam steering as a function of angle, range, and time. In this paper, we review the development of the FDA radar since its inception in 2006. Since the frequency offset attaches great importance in FDAs to determine the beampattern shape, initially much of the research and development were focused on designing the optimal frequency offsets for improved beampattern synthesis. Specifically, we analyze characteristics of the FDA beampattern synthesis using various frequency offsets. In addition to analyzing the FDA beampattern characteristics, this study also focuses on the neglected propagation process of the transmitted signals in the early FDA literature, and discuss the time-variant perspective of FDA beampatterns. Furthermore, FDA can also play a significant role in wireless communications, owing to its potential advantages over the conventional PAs. Therefore, we highlight its potential applications in wireless communication systems. Numerical simulations are implemented to illustrate the FDA beampattern characteristics with various frequency offset functions.

scholarly journals Implementation of Multiband Communication Using SDR for Remote Application

2020 ◽  
Author(s):  
Madhuri Gummineni ◽  
Trinatha Rao Polipalli
Keyword(s):  
Wireless Communication ◽  
Communication Systems ◽  
Low Cost ◽  
Wireless Communication Systems ◽  
Simulation Based ◽  
End To End ◽  
To Come ◽  
Multimode Operation ◽  
Reconfigurable Radio ◽  
Multi Mode

Abstract To develop Next Generation Wireless Communication a generic hardware design is required so that it can be driven by software to allow for future upgrades. Thus Reconfigurable Radio implements multi-band, multi-mode operation and interoperability with low-cost. For reducing response time between incompatible radios during emergencies interoperability is essential for a secure heterogeneous communication. Some of the Challenges identified for implementing reliable and reconfigurable wireless communication systems are: specific training required for using the equipment, end-to-end connectivity between devices, extending link capacity during the high peak utilization. Each device and architecture will differ based on the type of communication system. Interconnecting emerging fields enhances the performance , implementation helps to come across alternatives to overcome practical difficulties and challenges of connecting different fields to Cognitive Radio(CR). Earlier research gave prominence to theoretical and simulation-based work. This motivates us to verify interoperability in real time using SDR. This paper describes the implementation of a Multiband, multimode operation for establishing communication between different types of architecture i.e. VUSDR (HAM), Hack RF One, LoRa, RF module, GSM module and USRP N210 to prove reliability and end-to-end communication.

Design of New Reconfigurable and Miniature Microstrip Planar Antennas

2019 ◽  
pp. 223-257
Author(s):  
Ridouane Er-Rebyiy ◽  
Jamal Zbitou ◽  
Abdelali Tajmouati ◽  
Mohamed Latrach
Keyword(s):  
Communication Systems ◽  
Low Cost ◽  
Mobile Systems ◽  
Wireless Communication Systems ◽  
Planar Antennas ◽  
Printed Antennas ◽  
Crucial Component ◽  
Low Weight ◽  
Materials Used ◽  
State Of Art

Recently, wireless communication systems have developed rapidly and have become more mobile and small. This necessarily requires the adequacy of its design. The materials used should be as much as possible small and at a lower cost. So low cost with reduced volume and low weight are some of the major challenges that must be faced by the designer of modern telecommunications equipment. The microstrip planar antenna is an attraction and the most crucial component used in mobile systems, and its miniaturization is one of the research challenges. This chapter focuses on the concept of miniature reconfigurable antennas by presenting and discussing the state of art with contributions in designing reconfigurable miniature printed antennas.

New low-cost broadband CPW-fed planar antenna

2014 ◽  
Vol 8 (2) ◽  
pp. 271-276 ◽  
Author(s):  
Rachid Dakir ◽  
Jamal Zbitou ◽  
Ahmed Mouhsen ◽  
Abdelwahed Tribak ◽  
Amediavilla Sanchez ◽  
...  
Keyword(s):  
Communication Systems ◽  
Low Cost ◽  
Coplanar Waveguide ◽  
Microstrip Antennas ◽  
Design System ◽  
Wireless Communication Systems ◽  
Narrow Bandwidth ◽  
Measurement Results ◽  
Rectangular Microstrip Antenna ◽  
Comparison Of The Results

The narrow bandwidth of microstrip antennas is one of the most important features that restrict its wide usage. This paper presents a new coplanar waveguide-fed compact rectangular microstrip antenna with the improvement of the bandwidth using the slot geometry and cutting rectangular periodic edges for the patch radiator. To develop this structure, we have conducted many optimization and investigation using Momentum Software integrated into ADS “Advanced Design System” and comparison of the results with CST Microwave Studio. The comparison between the simulation and measurement results permits to validate the final achieved antenna with an improvement of the bandwidth. This antenna has wide matching input impedance ranging from 1.7 to 3.5 GHz with a return loss less than −10 dB, corresponding to bandwidth 69.7% at 2.6 GHz as a frequency center. The antenna achieved is a low cost, planar, and easy to be fabricated, thus promising for multiple applications in wireless communication systems. Details of the proposed antenna design and both simulated and experimental results are described and discussed.

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