Wireless Standards Research Articles

IoT Enabled Model with Virtual Assistant for Smart Home Applications

The Internet of Things (IoT) has emerged as a prominent technological opportunity, offering numerous professional prospects. It revolves around establishing wireless communication standards between devices and appliances to enhance daily human life. This particular project aims to create a secure and automated home environment by monitoring and controlling various home appliances using Wi-Fi as the primary communication protocol. Traditionally, wireless communication techniques like Wi-Fi and Bluetooth have been utilized for home automation. However, these methods have limitations such as short range and high costs. To overcome these challenges, this paper proposes the techniques of comfy home automation involve the efficient management of appliances like lights and fans, which not only provide convenience but also save time, reduce the need for manual intervention, enhance home security, and send SMS alerts to the owner in case of fire accidents or gas leakages through a dedicated mobile application. Additionally, it aims to train the virtual assistant to engage in enjoyable interactions with the homeowner, further enhancing the user experience. To implement this, this work utilizes the "NodeMCUESP8266" module, which will serve as the foundation for our system. The integration of this technology will prove especially beneficial for individuals who are physically challenged, elderly, or frequently away from home due to their busy schedules. By leveraging the power of IoT and mobile applications, this paper suggests a smart home automation solution that caters to the specific needs and preferences of homeowners, ultimately enhancing their quality of life.

On Scalability of FDD-Based Cell-Free Massive MIMO Framework.

Cell-free massive multiple-input multiple-output (MIMO) systems have the potential of providing joint services, including joint initial access, efficient clustering of access points (APs), and pilot allocation to user equipment (UEs) over large coverage areas with reduced interference. In cell-free massive MIMO, a large coverage area corresponds to the provision and maintenance of the scalable quality of service requirements for an infinitely large number of UEs. The research in cell-free massive MIMO is mostly focused on time division duplex mode due to the availability of channel reciprocity which aids in avoiding feedback overhead. However, the frequency division duplex (FDD) protocol still dominates the current wireless standards, and the provision of angle reciprocity aids in reducing this overhead. The challenge of providing a scalable cell-free massive MIMO system in an FDD setting is also prevalent, since computational complexity regarding signal processing tasks, such as channel estimation, precoding/combining, and power allocation, becomes prohibitively high with an increase in the number of UEs. In this work, we consider an FDD-based scalable cell-free network with angular reciprocity and a dynamic cooperation clustering approach. We have proposed scalability for our FDD cell-free and performed a comparative analysis with reference to channel estimation, power allocation, and precoding/combining techniques. We present expressions for scalable spectral efficiency, angle-based precoding/combining schemes and provide a comparison of overhead between conventional and scalable angle-based estimation as well as combining schemes. Simulations confirm that the proposed scalable cell-free network based on an FDD scheme outperforms the conventional matched filtering scheme based on scalable precoding/combining schemes. The angle-based LP-MMSE in the FDD cell-free network provides 14.3% improvement in spectral efficiency and 11.11% improvement in energy efficiency compared to the scalable MF scheme.

An Overview and Comparison of Wireless Technologies and Standards for Industrial Wireless Sensor Networks

The tremendous research and development has provided a number of wireless technologies and standards used for communication in Industrial Wireless Sensor Networks. The primary reason for writing this article is to study all available Wireless technologies and standards and to identify their area of usage, study different parameters like power consumption, functionality, communication range, transmission speed, data type etc. Another important and main reason of this article is to select best suitable technology for our next research. Various parameters of established technologies like Wireless HART, Zigbee, ISA 100.11a and Dash7 have been compared using a comparison table.

Use of Logarithmic Rates in Multi-Armed Bandit-Based Transmission Rate Control Embracing Frame Aggregations in Wireless Networks

Herein, we propose the use of the logarithmic values of data transmission rates for multi-armed bandit (MAB) algorithms that adjust the modulation and coding scheme (MCS) levels of data packets in carrier-sensing multiple access/collision avoidance (CSMA/CA) wireless networks. We argue that the utilities of the data transmission rates of the MCS levels may not be proportional to their nominal values and suggest using their logarithmic values instead of directly using their data transmission rates when MAB algorithms compute the expected throughputs of the MCS levels. To demonstrate the effectiveness of the proposal, we introduce two MAB algorithms that adopt the logarithmic rates of the transmission rates. The proposed MAB algorithms also support frame aggregations available in wireless network standards that aim for a high throughput. In addition, the proposed MAB algorithms use a sliding window over time to adapt to rapidly changing wireless channel environments. To evaluate the performance of the proposed MAB algorithms, we used the event-driven network simulator, ns-3. We evaluated their performance using various scenarios of stationary and non-stationary wireless network environments including multiple spatial streams and frame aggregations. The experiment results show that the proposed MAB algorithms outperform the MAB algorithms that do not adopt the logarithmic transmission rates in both the stationary and non-stationary scenarios.

Beyond 5G: Enabling ultrafast data transfer with microcomb technology

Researchers demonstrate proof-of-concept with higher carrier frequency than current 5G wireless standards.

Implementation of the Metamaterial Multiband Frequency Reconfigurable Antenna for IoT Wireless Standards

A reconfigurable metamaterial multiband antenna operating an octa-band resonating mode is designed for IoT wireless applications. Metamaterial cell split ring resonator (SRR) and quasi-complementary split ring resonator (CSRR) are printed on the back and front sides of the proposed antenna design to achieve the multiband characteristics. The PIN diode is implemented in a slotted ground section of the antenna structure to get different wireless standards by switching the diode ON/OFF. During reverse biased (OFF) mode of diode antenna operating at eight resonant frequencies 2.42, 4.34, 5.81, 8.45, 11.02, 13.98, 16.12, and 18.87 GHz covering the IoT wireless standards such as S, C, X, Ku, and K band to identify a variety of wireless applications such as WLAN, WAIC, ITU, Satellite, and radar communication. Simple structure, stable radiation pattern, multiband operation, frequency band reconfigurability feature, reasonable gain, and efficiency are the significant features of the proposed metamaterial multiband antenna.

An FPGA-Based Reconfigurable FIR Filter for SDR Applications

This article presents a proposal of a reconfigurable FIR filter capable of covering the most common wireless communication standards on software-defined radio applications. The filter was implemented using a low-cost field programmable gate array, Cyclone IV EP4CE22F17C6 model from Altera®. System design is presented together with simulation results. Validation is done for a 500 kHz base-band noisy signal. The synthesized design uses 5,259 logic elements of which 4,778 were used for combinational logic blocks and 513 for dedicated logic registers, which represents 22% of total used FPGA capacity. The maximum sampling frequency supported by the architecture is 23.24 MHz.

Improved TDD operation on Software-Defined Radio platforms towards future wireless standards

Software-Defined Radio (SDR) platforms are valuable for research and development activities or high-end systems that demand flexible wireless protocols. While low-latency digital baseband processing can be achieved using a dedicated processing unit, like an FPGA or hardware accelerator, its multi-purpose Radio Frequency (RF) front-end often poses a limitation. Zero Intermediate Frequency (ZIF) transceivers are favorable for SDR, however, even for Time Division Duplex (TDD) systems, these transceivers suffer from self-interference when the transmitting and receiving Local Oscillator (LO) is set to the same frequency. To achieve low self-interference, switching from receiving to transmitting mode is needed. However, the time this takes (turnaround time, TT) for configurable RF front-ends often violates the strict timing requirements of protocols like Wi-Fi and 5G, which require response times in the order of microseconds. In this work, we first evaluate the advantages and disadvantages of several methods to suppress self-interference of a ZIF transceiver. Next, a novel approach is proposed, which can reduce the TT to as low as 640ns using the widely used AD9361 configurable ZIF RF front-end, while the noise floor is at the same level as achieved by the conventional way of switching between transmit and receive mode. We have realized and validated this approach using openwifi — an open-source Wi-Fi implementation on SDR. As a result, the receiver sensitivity is improved by up to 17dB in the 2.4GHz band and 9.5dB in the 5GHz band, for over-the-air transmissions.

Методика подвійної автентифікації для RFID систем управління доступом з підвищеним рівнем захисту

Currently, there are no uniform international standards for devices and systems that use radio frequency identification technology. Using tag alone as an identifier imposes certain restrictions on the level of protection of access control systems, since the unique tag identifier can be easily copied, so two-step authentication is required. The second level of protection can be a digital password entered via the keyboard. The work presents dual authentication technique for access control to the premises. Increasing the level of protection of radio frequency identification systems is achieved by the additional use of a digital password encrypted using a symmetric block encryption algorithm and recorded on the tag. This removes any restrictions on the number of registered users in the system, because passwords and IDs are stored on tags. The laboratory model of the device is based on the NodeMCU-32S Opensource platform with an RFID module that allows connection to most fog and cloud services of the Internet of things. The development is based on the ESP32 controller, which supports the necessary set of commands and hardware for implementing the methodology, in particular, wireless standards and communication protocols, hardware-accelerated encryption. The Cayenne service from MyDevices was chosen as the cloud platform, which made it possible to configure the device using the publish-subscribe messaging protocol and develop a graphical user interface. A log on the Cayenne platform is used to keep track of users, a character display is used to display the current status and settings of the device, and a serial interface is used to debug work algorithms. The software is implemented using the Arduino C programming language.

Why Is White Noise Not Enough? Using Radio Front-End Models While Designing 6G PHY

Each subsequent generation of wireless standards imposes stricter spectral and energy efficiency demands. So far, layered wireless transceiver architectures have been used, allowing for instance to separate channel decoding algorithms from the front-end design. Such an approach may need to be reconsidered in the upcoming 6G era. Especially hardware-originated distortions have to be taken into account while designing other layer algorithms, as high throughput and energy efficiency requirements will push these devices to their limits, revealing their non-linear characteristics. In such a context, this paper will shed some light on the new degrees of freedom enjoyed while cross-layer designing as well as controlling multicarrier and multiantenna transceivers in 6G systems.

Energy efficiency augmentation in UWA‐OFDM transducer by peak to average power ratio alleviation through hybrid companding approach

AbstractOrthogonal frequency division multiplexing (OFDM) is a compelling contender for next‐generation fixed and wireless standards to realize high data transmission rates in underwater acoustic (UWA) systems. A specific challenge before transmission over the transducers of the UWA system within an OFDM signal is the high peak to average power ratio (PAPR), which severely affects the energy efficiency of the UWA system. This work aims to enhance the energy efficiency of the UWA system by alleviating the stumbling block mentioned earlier within the OFDM. Moreover, we recommend and design a methodology that incorporates modified repeated frequency‐domain filtering and clipping (RFC) and companding techniques to restrain the PAPR obstacle. Additionally, the modified RFC utilizes various companding techniques (including linear and nonlinear techniques) to achieve the desired objectives without complexity augmentation of the system. We simulate and test our proposed approach against four major parameters: PAPR, bit error rate, energy efficiency, and system performance gain. Statistical results show that our technique offers .36 high‐power amplifier power efficiency (), which is comparatively better than OFDM with selective mapping, OFDM with partial transmit sequences, and OFDM with other hybrid approaches.

A novel design of multi-user sequence set for joint vehicular radar-communication based on Oppermann family

In this paper, a novel multi-user sequence set which are to be potentially used as communication preambles for joint vehicular radar and communication using Oppermann sequences is proposed. Herein, a set of Oppermann sequences with suitable auto-ambiguity functions (AF) and cross-ambiguity functions (AF) properties have been proposed. Moreover, a channel estimation algorithm using the designed Oppermann sequences is also proposed. The designed preamble, composed of optimized Oppermann sequences is an appropriate candidate for wireless standards, where both channel estimation and multi-user vehicular radar sensing are jointly pursued. The simulation results demonstrate that the designed sequences provide a significant performance improvement for vehicular radar sensing and don't degrade the channel estimation accuracy. The proposed optimized Oppermann sequences have better auto- and cross-AF compared existing Golay complementary sequences (used in IEEE 802.11ad as preamble), Zadoff-Chu sequences (used in 5G to generate preambles for the Physical Random Access Channel (PRACH)) and the non-optimized Oppermann sequences. Specifically, compared to the preamble composed of Golay complementary sequences in IEEE 802.11ad, the proposed sequences reduce the maximum sidelobe level of the auto-AF and maximum value level of cross-AF by at least 2 and 2.85 times, respectively. The target can still be accurately detected in mutual interference scenario caused by multiple radars in the vicinity. Both the sequences, when used for channel estimation achieve the CRLB limit. Both the proposed sequences and Golay complementary sequences, when used for channel estimation achieve the Cramer-Rao Lower Bound.

A modified sierpinski carpet antenna structure for multiband wireless applications

Multiband patch antenna has a very important part in the communication devices and systems. The benefits in designing and testing of Sierpinski carpet geometries for a low profile, cost effective multiband microstrip patch antenna for wireless standards is reviewed in this paper. The basic structure of the patch antenna is designed using the FR4 substrate with a thickness of 1.3 mm. The designed patch antenna structure is excited using the microstrip feed system. The Sierpinski carpet antenna structure is designed and simulated using High Frequency Structural Simulator (HFSS) software. The available Sierpinski carpet antenna structure in the literature is modified to make the preferred radiation patterns. The effects of the iterations of the modified Sierpinski carpet antenna structure over the generated return loss plots are discussed in this work. Based on the generated multiband behavior in the simulated results, the accomplishment of the designed antenna in the wireless domain was analyzed.

Toward 6G Vehicle-to-Everything Sidelink: Nonorthogonal Multiple Access in the Autonomous Mode

The cellular vehicle-to-everything (C-V2X) sidelink technology, specified in the long-term evolution (LTE) and further improved in the 5G new radio (NR) standards to facilitate direct data exchange between vehicles, will play a crucial role in revolutionizing transportation systems. However, the demand for very high reliability and ultralow latency services especially challenges the sidelink resource allocation mechanism when performed by distributed vehicles, in the so-called <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">autonomous</i> mode. One of the major causes of ­performance degradation is the resource allocation mechanism, which was designed for orthogonal multiple access (OMA) and can generate interference and collisions under high load conditions. In this context, here we argue in favor of the use of non-OMA (NOMA) as a game changer for the sidelink in the upcoming 6G V2X, and the purpose of this article is to provide a reference for further intriguing studies in the field. Additionally, the gain achievable over conventional allocation schemes by enabling NOMA through the use of successive interference cancelation (SIC) at the receiver is measured through realistic simulations conducted when considering the latest C-V2X specifications.

Digital Technology Evolution of the Industrial Revolution From 4G to 5G in the Context of the Challenges of Digital Globalization

The development of a new generation of information technologies and engineering equipment directly affects the path of scientific research and innovation. As a result of these processes, new trends are developing, such as information technology, AI, digital education and medicine, etc. The 4th Industrial Revolution is the result of digital transformation. These processes are the basis for the evolution from the 4th to the 5th industrial revolution. The article analyses the fifth generation of 5G mobile telecommunication systems, which is a new wireless communication standard that will bring significant improvements in the data transfer speed of connecting many devices simultaneously.

Implementation of polyphase digital down converter for wireless applications

This paper briefs the hardware-efficient polyphase digital down converter (DDC), which reduces the input sampling frequency to 3.64 GHz and produces a complex output to meet the IEEE 802.11ah wireless network standard. The design comprises a polyphase mixer (PM) filter and a lowpass polyphase finite impulse response (PFIR) filter. The PM filter uses a cascaded integrator comb (CIC) decimation filter based on multiplexer technology to potentially process parallel input interfaces and considerably reduce the sampling rate. The time-sharing mechanism of the CIC filter performs an efficient hardware implementation. Again, the improved design technique of the PFIR filter can effectively increase the operating speed and optimize power consumption. The proposed design offers high flexibility due to programmable sampling rate factors that can support multistandard communication systems. In addition, the design includes the truncation mechanism to protect against overflow errors and the fixed-point data type in each filter node to minimize the area requirements. The presented polyphase DDC is tested using the field-programmable gate array (FPGA) platform targeting the Xilinx Kintex-7 device. According to experimental results, the described DDC significantly reduces the logical resources and power dissipation associated with earlier design structures. The functional verification is tested to ensure the validation of the suggested design.

Terahertz Communications for 6G and Beyond Wireless Networks: Challenges, Key Advancements, and Opportunities

The unprecedented increase in wireless data traffic, predicted to occur within the next decade, is motivating academia and industries to look beyond contemporary wireless standards and conceptualize the sixth-generation (6G) wireless networks. Among various promising solutions, terahertz (THz) communications (THzCom) is recognized as a highly promising technology for the 6G and beyond era, due to its unique potential to support terabit-per-second transmission in emerging applications. This article delves into key areas for developing end-to-end THzCom systems, focusing on physical, link, and network layers. Specifically, we discuss the areas of THz spectrum management, THz antennas and beamforming, and the integration of other 6Genabling technologies for THzCom. For each area, we identify the challenges imposed by the unique properties of the THz band.We then present main advancements and outline perspective research directions in each area to stimulate future research efforts for realizing THzCom in 6G and beyond wireless networks.

Lossy State Communication over Fading Multiple Access Channels.

Joint communications and sensing functionalities integrated into the same communication network have become increasingly relevant due to the large bandwidth requirements of next-generation wireless communication systems and the impending spectral shortage. While there exist system-level guidelines and waveform design specifications for such systems, an information-theoretic analysis of the absolute performance capabilities of joint sensing and communication systems that take into account practical limitations such as fading has not been addressed in the literature. Motivated by this, we undertake a network information-theoretic analysis of a typical joint communications and sensing system in this paper. Towards this end, we consider a state-dependent fading Gaussian multiple access channel (GMAC) setup with an additive state. The state process is assumed to be independent and identically distributed (i.i.d.) Gaussian, and non-causally available to all the transmitting nodes. The fading gains on the respective links are assumed to be stationary and ergodic and available only at the receiver. In this setting, with no knowledge of fading gains at the transmitters, we are interested in joint message communication and estimation of the state at the receiver to meet a target distortion in the mean-squared error sense. Our main contribution here is a complete characterization of the distortion-rate trade-off region between the communication rates and the state estimation distortion for a two-sender GMAC. Our results show that the optimal strategy is based on static power allocation and involves uncoded transmissions to amplify the state, along with the superposition of the digital message streams using appropriate Gaussian codebooks and dirty paper coding (DPC). This acts as a design directive for realistic systems using joint sensing and transmission in next-generation wireless standards and points to the relative benefits of uncoded communications and joint source-channel coding in such systems.

Gain Enhancement of Metamaterial-Inspired Multiband Antenna for Wireless Applications

In this project, a metamaterial-inspired multiband antenna with a size of 32 × 22 × 1.6 mm3 is designed on FR4 dielectric material that operates at eight wireless standards with gain enhancement application. The antenna has electrical dimension of 0.2581 λ × 0.1775 λ × 0.0129 λ (32 × 22 × 1.6 mm3), at a lower resonant frequency of 2.42 GHz. The proposed design has slots with Quasi CSRR (complementary split ring resonator) and SRR (split ring resonator) cell, respectively. Antenna achieves octa-band resonant modes for IoT and wireless applications S-band WLAN, bottom C-band WAIC, WLAN, bottom X-band, superior X-band, bottom Ku-band, superior Ku-band and bottom K band with optimized radiation properties. By the implementation of the proposed frequency selective surface (FSS) with design, antenna gain is improved for the resonant bands.

Hardware Efficient Reconfigurable Digital Down Converter for Software Radio Receiver

ABSTRACT This paper describes a reconfigurable digital down converter (DDC) that can reduce the input sampling frequency from 128 MHz to an output of 1 MHz on a field-programmable gate array (FPGA) device. The proposed design employs a polyphase mixer followed by a half-band (HB) filter and a finite impulse response (FIR) filter. All the decimation filters involve polyphase architectures, enabling efficient hardware implementation. The polyphase mixer can reduce the high sampling rate frequency, and combining both HB and FIR filters results in a complex down-converted baseband spectrum. In addition, the modified HB filter reduces multiplier units, and the proposed FIR filter saves the delay elements. Using the optimal hardware description language (HDL) programming style, the design can further improve the area efficiency without sacrificing functionality. To evaluate the performance, the design has been implemented on the Kintex-7 Xilinx FPGA device. Experimental outcomes show that the proposed design significantly reduces hardware costs associated with other existing designs. Finally, a verification test certifies that the DDC has achieved a satisfactory spurious-free dynamic range (SFDR) of 115 dB. The high sampling rate and parallel processing capabilities of the proposed DDC make it an attractive solution for any software radio standard.