Band Wireless Research Articles

Quantum Noise-Assisted Coherent Radio-Over-Fiber Cipher System for Secure Optical Fronthaul and Microwave Wireless Links

This article reports on a symmetric-key direct-data encryption technique that directly protects the interception of optical and microwave signals from physical layer in a coherent analog radio-over-fiber (RoF) system. Secrecy is realized by signal masking by quantum (shot) noise. The quantum noise masking for the encryption is achieved by converting data into extremely high-order signals at an optical frequency. After signal transmission over an optical fronthaul link, the frequency of the encrypted signal is shifted to a microwave frequency via an optical heterodyne process using a local oscillator for wireless transmission. The effect of the quantum noise masking is naturally and seamlessly kept in the heterodyne process. We experimentally demonstrate 12 Gbit/s coherent RoF cipher systems utilizing the quantum noise masking for a 30 GHz wireless band. Adequate signal quality and high security against interception with sufficient quantum noise masking are simultaneously achieved in the optical fronthaul and microwave wireless links.

The Impact of Rain on Short ${E}$ -Band Radio Links for 5G Mobile Systems: Experimental Results and Prediction Models

The results from 1 year of data collected during an electromagnetic wave propagation experiment at ${E}$ -band are presented. The research activity originates from the collaboration between Politecnico di Milano, Milan, Italy, and the Huawei European Microwave Centre in Milan, which installed short (325 m) terrestrial links operating at 73 and 83 GHz, connecting two buildings in the university main campus. The received power data are processed, using a novel approach, to identify rain events and to remove the wet antenna effect, with the aim of accurately quantifying the fade induced by precipitation, $A_{R}$ . Moreover, $A_{R}$ is estimated by taking advantage of the ancillary data collected by the laser-based disdrometer collocated with the link transceivers. The results definitely point out the higher prediction accuracy achieved by exploiting the information on the rain drop size. A full year of data are used as reference to test the accuracy of the statistical prediction model for terrestrial links currently recommended by the ITU-R, which reveals a large overestimation. Finally, alternative models providing a higher accuracy are proposed and their accuracy assessed.

A Compact Frequency and Pattern Reconfigurable Cross Slot Notch Antenna for ISM Band Medical and Radio Navigation Applications

A Compact Frequency and Pattern Reconfigurable Cross Slot Notch Antenna for ISM Band Medical and Radio Navigation Applications

A 3-Transistor Low Power Rectifier for Wideband RF Energy Harvesting with a Threshold Voltage Compensation Technique using 45 nm Technology

With the advent of modern wireless communication technology and increasing requirement of high speed network, network life-time is becoming a major area of concern. The need of network power management is gaining attention with the high data network in place and is making a paradigm shift towards green communication. Hence embedding the RF energy harvesting (EH) capability in a wireless network is becoming inevitable. To make RF EH a reality a high frequency rectifier is indeed indispensable along with other circuits in the system. The RF energy needs to be harvested from the available sources in the ambience. It is also seen that the current generation of RF sources radiates at a very low signal power. So, to successfully convert and store this energy, the rectifier must not only be able to provide a sufficiently higher percentage conversion ratio (PCE) but also be able to cater it at a lower range of signal power. This paper presents the design and analysis of a simplified 3-transistor high frequency rectifier. A threshold voltage compensation technique is also incorporated and it achieves a PCE upto 85% at -2dBm in its single stage implementation. This is observed to be one of the highest in-class efficiency as compared to recently reported designs. From the frequency response it is seen to exhibit wide band performance spanning almost all popular wireless bands. The dynamic power dissipation (DPD) is calculated to be 6.25pW at -2dB, whereas the leakage power (LP) is observed to be zero.

Design and Analysis of a Modified TG Rectifier with Substrate Voltage Compensation Techniques at 45 nm Technology for High Frequency Low Power RF Energy Harvesting

- The development of latest generation of wireless communication standards in the recent years has created enormous possibility to deploy high speed wireless network throughout the globe. There is always demand for high speed, seamless data connectivity. But it is a well-known fact that the increase in speed always makes the power consumption higher. Also while attempting to cater to the need of connectivity to a remote location, the major bottleneck is the availability of power. Hence incorporating self-sustainability to a wireless network is becoming the need of the hour. Radio frequency (RF) energy harvesting (EH) is gaining much attention in contemporary communications in this context. In the design of an EH system, the high frequency rectifier plays a significant role. Apart from several design hurdles that exist in a high frequency rectifier, to attain a high percentage conversion efficiency (PCE) at lower input power is the primary design challenge. This paper presents a design of a modified transmission gate (TG) based high frequency rectifier with two substrate voltage compensation techniques, viz. capacitor and MOS based compensation for RF EH system.The proposed capacitor and MOS based techniques enable the rectifier to achieve a PCE upto 86% and 92% at -5dBm respectively in its single stage implementation. This can be claimed to be the highest in-class efficiency as compared to recently published works. The frequency responses with both the techniques depict a wide band performance covering all popular wireless bands. The dynamic power dissipations (DPD) observed are 12nW and 16nW at -5dB, whereas the leakage power (LP) is 20x10-51W and zero respectively. Further such an performance are obtained using minimal number of transistors, viz. 4 and 5 respectively.

5G TECHNOLOGIES AND BUSINESS ASPECTS: HIGH-LEVEL POINT OF VIEW

This paper covers technological and business aspects of 5G mobile networks at their initial targeted year for acceptance, 2020. It gives a high level view beyond 5G, toward the next generation which is referred to here as 6G. The 5G introduces New Radio (NR) in sub-6 GHz bands and also in mm Wave bands above 24 GHz. The paper analyzes 5G novelties such as network function virtualization and network softwarization, which means that 5G Next Generation Core and 5G NR access network are built by using different functions in split user and control planes. That provides the basis for the network slicing approach, with three main service types defined for the 5G era: enhanced Mobile Broadband (eMBB), massive Machine Type Communication (mMTC) and Ultra-Reliable Low-Latency Communica­tion (URLLC), which may be provided via separate network slices as logically separated network partitions. Consid­ering the 5G business aspects, the paper states that the initial 5G driver is eMBB, then follows mMTC, and last to be deployed is the most demanding one, the URLLC. Finally, with many 5G network functions, also exposed to the third parties such as Over-The-Top (OTT) service providers, with constantly increasing volume of traffic and number of connected devices, this paper also includes future use of Machine Learning and generally Artificial Intelligence (AI) is becoming necessity for further expansion of the mobile world beyond 5G, toward the 6G in 2030s.

Integrated bluetooth/LTE2600 superwideband monopole antenna with triple notched (WiMAX/WLAN/DSS) band characteristics for UWB/X/Ku band wireless network applications

In this manuscript, a compact superwideband monopole antenna with triple notched band characteristics is presented and is experimentally investigated. Proposed antenna is also suitable for lower band of applications including Bluetooth and LTE2600 bands. Superwideband bandwidth with bandwidth ratio ≥ 10:1 is obtained by using two identical ellipse which are placed at 70° with reference to major axis. A fractal stub is used to notch WiMAX interfering band while WLAN and DSS bands are notched by etching modified rectangular slots on the radiating patch. Antenna also constitutes slotted ground with chamfered corners for better matching of impedance. Proposed antenna is also investigated in terms of frequency, time and space domain. Antenna offers a wider superwideband bandwidth with VSWR ≤ 2 for 2.34 GHz to 20.00 GHz. In time domain, antenna offers constant group delay in entire operating bandwidth and acceptable impulse response for input signal. Also, antenna offers maximum gain of 4.98 dBi and radiation efficiency of 89%. Stable radiation pattern and above features of proposed antenna suggest antenna to be a good candidate for numerous applications in wireless system.

On Developing a New 5G Spectrum Usage Fee Model for Indonesia

This paper reports on the development of the 5G spectrum usage fee in Indonesia. The fee was first applied in 2010 to charge mobile network operators (MNOs) that provided cellular services. However, cellular technologies have improved rapidly from 2G, 3G, 4G to 5G, and many modern innovative cellular services demand larger spectrum bandwidth. Therefore, the existing spectrum usage fee must be revised to meet the needs of the community better and to improve the efficiency and effectiveness of spectrum use. This study modifies the characteristics of the existing cost structure of the Indonesian spectrum usage fee, designing and proposing a new 5G spectrum usage fee model to support 5G technology usage scenarios and maximize the benefits of the mid-band (3.5 GHz), mmWave, or high band radio frequencies (26 GHz and 28 GHz). The new spectrum usage fee model includes spectrum-sharing parameters (non-orthogonal spectrum-sharing and orthogonal spectrum sharing) and private network to optimize the use of the available spectrum because the new proposing formula does not use the nationwide population, but instead, it uses the population within a specific area with both human and non-human (machine) populations. This new model is expected to help regulators prepare 5G technology regulations for application in Indonesia.

A Three-Layered Adjustable Frequency-Selective Surface for Wireless Applications

A three-layered adjustable frequency-selective surface (FSS) is proposed and investigated. The FSS consists of a main resonator in the middle layer and two subresonators in the upper and lower layers of a sandwich structure. The resonant frequency can be varied by shifting the upper and lower layers symmetrically. This has the advantages that the same frequency characteristics can be obtained in both vertical and horizontal polarizations and that its fabrication is easy, eliminating the need for electronic elements such as varactor diodes to control capacitance, although the FSS is not suitable for situations that require real-time tuning. This article confirms that the resonant frequency can be varied from $f_{0}$ to $1.7f_{0}$ in a microwave band which covers multiple wireless bands, with good angular stability in both vertical and horizontal polarizations, by shifting the upper and lower layer overlaps by up to 1.8 mm. Note that $f_{0}$ is the lowest resonant frequency, and the size of a unit cell is varied from $0.066\lambda $ to $0.125\lambda $ . Also, the adjustment capability and the angular stability of an FSS fabricated by using a silver inkjet printer are experimentally demonstrated, by simply stacking and shifting the three films.

Bandwidth Enhanced Multislot Rectangular Patch Antenna for UWB and X Band Wireless Applications

The main aim of this work is to design a compact Rectangular shaped Multislot patch antenna for Ultra Wide Band (UWB) and X band applications. The proposed antenna has a condensed size of 35*30*1.6mm3. The antenna consists of a rectangular patch with microstrip line feed etched on FR4-epoxy substrate with dielectric constant of 4.4. To improve the bandwidth, circular slots are made in patch and the ground plane. The proposed antenna achieves wide bandwidth of 12.7GHz (3.3-16 GHz) having four resonance frequency with good return loss and maximum gain of 9.64dBi. The antenna is designed, simulated and analyzed by using HFSS (High Frequency Structural Simulator). The charisma of this design is that it employs single patch that makes it easy to fabricate and cost-effective as well.

SCATTER PHY: An Open Source Physical Layer for the DARPA Spectrum Collaboration Challenge

DARPA, the Defense Advanced Research Projects Agency from the United States, has started the Spectrum Collaboration Challenge with the aim to encourage research and development of coexistence and collaboration techniques of heterogeneous networks in the same wireless spectrum bands. Team SCATTER has been participating in the challenge since its beginning, back in 2016. SCATTER’s open-source software defined physical layer (SCATTER PHY) has been developed as a standalone application, with the ability to communicate with higher layers through a set of well defined messages (created with Google’s Protocol buffers) and that exchanged over a ZeroMQ bus. This approach allows upper layers to access it remotely or locally and change all parameters in real time through the control messages. SCATTER PHY runs on top of USRP based software defined radio devices (i.e., devices from Ettus or National Instruments) to send and receive wireless signals. It is a highly optimized and real-time configurable SDR based PHY layer that can be used for the research and development of novel intelligent spectrum sharing schemes and algorithms. The main objective of making SCATTER PHY available to the research and development community is to provide a solution that can be used out of the box to devise disruptive algorithms and techniques to optimize the sub-optimal use of the radio spectrum that exists today. This way, researchers and developers can mainly focus their attention on the development of smarter (i.e., intelligent algorithms and techniques) spectrum sharing approaches. Therefore, in this paper, we describe the design and main features of SCATTER PHY and showcase several experiments performed to assess the effectiveness and performance of the proposed PHY layer.

5G and Net Neutrality

Industry observers have raised the possibility that European network neutrality regulations may obstruct the deployment of 5G. To assess those claims, this Chapter describes the key technologies likely to be incorporated into 5G, including millimeter wave band radios, massive multiple input/multiple output (MIMO), ultra-densification, multiple radio access technologies (multi-RAT), and support for device-to-device (D2D) and machine-to-machine (M2M) connectivity. It then reviews the business models likely to be associated with 5G, including network management through biasing and blanking, an emphasis on business-to-business (B2B) communications, and network function virtualization/network slicing. It then lays out the network neutrality regulations created by the EU in 2015 as well as the nonbinding interpretive guidelines issued by the Body of Body of European Regulators for Electronic Communication (BEREC) in 2016 and assesses how they will be applied to 5G. Network neutrality’s impact on 5G will likely to be determined by the way that the exceptions for reasonable traffic management and specialised services are interpreted. A broad interpretation should accommodate network slicing and other new business models needed to support the deployment of 5G, while a narrow interpretation could restrict innovation and investment.

A Wideband High-Gain Planar Integrated Antenna Array for $E$ -Band Backhaul Applications

A novel wideband high-gain planar antenna array for $E$ -band backhaul applications is presented in this article. The antenna element is composed of a substrate integrated waveguide (SIW) cavity-backed patch and a stepped waveguide horn. The SIW cavity-backed patch is worked as wideband waveform and impedance transformer to excite the stepped waveguide horn on the upper layer. The stepped waveguide horn is employed to enhance the gain of the antenna element by increasing the radiation aperture. Based on the proposed antenna element, a $2 \times 2$ subarray with element spacing larger than a wavelength is designed. A groove, which works as secondary radiation source, is etched between the elements to improve the gain and suppress the high sidelobes of the $2 \times 2$ subarray. By taking the advantage of the groove, the $2 \times 2$ subarray achieves a maximum boresight gain of 17 dBi and an −10 dB impedance bandwidth of 21.8% from 70 to 87 GHz. For further enhancing the gain, a prototype including $16 \times 16$ elements is manufactured and measured. The experimental results confirm that the proposed antenna achieves the −10 dB impedance bandwidth of 22.4% from 71 to 88.5 GHz and a peak gain of 28.8–30.9 dBi. With the merits of a wider operating bandwidth, high gain, low profile, and low cross-polarization, the proposed antenna array is suitable for application in the $E$ -band wireless backhaul systems.

A Compact Rectangular Microstrip Patch Antenna Loaded with Stubs and Defected Partial Ground Structure for UWB Systems

This paper presents the prototype and simulations of a compact rectangular microstrip patch antenna for ultra-wideband applications. The proposed antenna is printed on FR4 (Flame Retardant) substrate with relative permittivity of 4.4, dielectric loss tangent of 0.0024 and the dimensions of 57 × 25 × 1.57 mm3 . The radiating patch of the antenna is loaded with two rectangular stubs along its upper and lower edges and an equilateral triangular notch is truncated from the reduced ground plane to achieve optimum results in terms of bandwidth and reflection coefficient. It is fed along the centerline of symmetry by 50Ω microstrip feed line. The simulated return loss ( ) characteristics show that the proposed antenna has a capability of covering the wireless bands from 0.17GHz to 7.25GHz with impedance bandwidth of 7.08GHz and exhibits a peak gain of 5dB at 7.25GHz which is acceptable for UWB systems.

Electromagnetic interference suppression in stacked patch antenna using complementary split ring resonator

AbstractA novel attempt is made by creating the stacked sequences of two different frequencies that provide the intended performance by suppressing the harmonic interferences between them. This electromagnetic interference (EMI) is suppressed in stacked system by incorporating the circular complementary split ring resonator (CCSRR) in the ground plane. The proposed system consists of two patch antennas operating at 2 GHz and 4 GHz with CCSRR for harmonic suppression. The lower rung antenna operates at 2 GHz fed by inset feeding and the top rung antenna operates at 4 GHz fed by coaxial feeding such that both radiators share a common ground plane. The lower rung antenna (2 GHz) has its first harmonic at 4.02 GHz with the magnitude of 11.5 dB that ensue an EMI to the other antenna operating at 4 GHz (top rung antenna in the stacked system). By introducing the CCSRR beneath the microstrip feed line (2 GHz), the EMI is suppressed. The simulated and measured results are in good agreement. Moreover, the proposed antenna finds its application in radar target scanning, narrow band channel selector, and low power narrow band wireless receivers.

A dual threshold listen-before-talk for unlicensed LTE systems

The insufficient wireless frequency bands are likely to arise with the increase in mobile traffic demand. Many mobile operators suffer from a high annual increase in the cost of licensed wireless bands. Unlicensed bands present a potential opportunity for mobile operators. A single 5-GHz band with a large bandwidth provides faster transmission for each user. However, interference caused by existing wireless transmissions, such as Wi-Fi in unlicensed bands, is a serious issue in the effective utilization of unlicensed bands by mobile operators. The Listen-Before-Talk (LBT) was proposed as a promising method to ensure the coexistence of Wi-Fi and commercial mobile services such as LTE. We focus on effective control of the contention window (CW) size to maximize the operability of LBT. Control of the CW size depends on the repetition of extended clear channel assessment (ECCA). We introduce a dual threshold system that counts the repetition of ECCA. The newly developed NS-3-based unlicensed band network simulator shows the effectiveness of the proposed control mechanism. The results indicated that the advantage of the proposed method improves 4.3–7.6% than traditional LBT method. We develop a composite metric of throughput and fairness to evaluate the performance of LTE-LAA access.

Investigation of Multilayer Print Circuit Board Probe With Temperature Compensation for Ultra-Wideband Near-Field Measurement

A novel ultra-wide band wireless probe applied to near-field electromagnetic measurement is presented in this paper, in which the probe is built on an FR-4 substrate with three layers. This paper presents both simulation and measurement study of the probe performance affected by various factors including the vias influence and terminal soldering. A temperature compensation circuit is designed to deal with the influence of temperature variation of the printed circuit board substrate. To assess the effectiveness of the proposed probe, the return loss, gain, and radiation pattern are simulated and experimentally tested. Both simulation and measurement demonstrate that the probe working frequency ranges from 3.1 to 10.6 GHz and the gain is greater than −50 dBm. Moreover, the tested results show that the probe has good stability in terms of temperature, and that it is suitable for the electromagnetic interference (EMI) near-field measurement.

Experimental Investigation of a Planar Antenna with Band Rejection Features for Ultra-Wide Band (UWB) Wireless Networks

The Federal Communication Commission (FCC) has authorized the use of unlicensed ultra-wide band (UWB) spectrum in the frequency range from 3.1 to 10.6 GHz for a variety of short-range applications, including wireless monitors and printers, camcorders, radar imaging, and personal area networks (PANS). However, the interference between coexisting narrowband channels and UWB signals that share the same spectrum should be avoided by designing UWB antennas with band notch characteristics. This work presents a printed monopole antenna (PMA) with slots of different shapes etched in the radiating element to obtain band rejection in the three coexisting communication bands, i.e., Worldwide Interoperability for Microwave Access (WiMAX), Wireless Local Area Network (WLAN), and International Telecommunication Union (ITU). A rectangular slot is etched to reject the WiMAX band (3.01-3.68 GHz), an upturned C slot stops the WLAN band (5.18-5.73 GHz) while an inverted-U slot halts the ITU frequency band (7.7-8.5 GHz). The proposed antenna occupies a volume of 32 x 30 x 1.6 mm3 and it radiates efficiently (>90%) with a satisfactory gain (>1.95 dBi) in the unnotched UWB frequency range. The simulations are performed in High Frequency System Simulator (HFSS), while the measurements are conducted in antenna measurement facility and found in close agreement with the former.

GreenLoading: Using the citizens band radio for energy-efficient offloading of shared interests

Cellular networks are susceptible to being severely capacity-constrained during peak traffic hours or at special events such as sports and concerts. Many other applications are emerging for LTE and 5G networks that inject machine-to-machine (M2M) communications for Internet of Things (IoT) devices that sense the environment and react to diurnal patterns observed. Both for users and devices, the high congestion levels frequently lead to numerous retransmissions and severe battery depletion. However, there are frequently social cues that could be gleaned from interactions from websites and social networks of shared interest to a particular region at a particular time. Cellular network operators have sought to address these high levels of fluctuations and traffic burstiness via the use of offloading to unlicensed bands, which may be instructed by these social cues. In this paper, we leverage shared interest information in a given area to conserve power via the use of offloading to the emerging Citizens Broadband Radio Service (CBRS). Our GreenLoading framework enables hierarchical data delivery to significantly reduce power consumption and user fairness variation and includes a Broker Priority Assignment (BPA) algorithm to select data brokers for users. With the use of in-field measurements and web-based Google data across four diverse U.S. cities, we show an order of magnitude power savings via GreenLoading over a 24-hour period, on average, and power savings up to 97% at peak traffic times. Finally, we consider the role that a relaxation of wait times can play in the power efficiency of a GreenLoading network.

Study on known models of NB-IoT Applications in Iraqi environments

Internet of things (IoT) considerably changes connectivity requirements, in particular concerning longer battery life, lower device costs, lower deployment costs, increased support and coverage for a lot of devices. Starting from those necessities, numerous various cellular and non-cellular low power WAN which could be abbreviated to (LPWAN) solutions emerged lately and are challenging for business related to IoT and the general market of connectivity. Therefore, in this study, Narrowband IoT main characteristics are explained, as well as, the suitability for different IoT applications in smart cities industry. The Narrowband IoT, which could be abbreviated to (NB-IoT), is known as a LPWAN technology of radio criterion which was presented for enabling the connections of various services and devices with the use of cellular tele-communication bands. NB-IoT can be defined as a narrow band radio technology that was created for internet of things (IoT) which is considered as a wide area of Mobile internet of things (MIoT) techniques which were published as a standard through 3GPP (third Generation Partnership Project), applications for NB-IoT could be very wide range and different topics, within this paper suggested NB-IoT applicable models for application in Iraqi environment to solve many problems (Smart white goods, Smart logistics, Smart electricity metering and Smart street lighting). These models based on NB-IoT technologies which are not yet provided by communications providers in Iraq (zain, Asia, korek).