Physical Layer Architecture Research Articles

Research and Development of Manufacturing Management System

MES system is an integrated information system integrating multiple functional modules, which is used to manage and monitor the production process and improve the production efficiency and quality. With the rapid development of the manufacturing industry, the manufacturing management system (MES) has become a key technology to improve the production efficiency and product quality of the manufacturing enterprises. In this paper, we deeply study and discuss the key technology and application of MES system. Through the design of the physical layer and software layer architecture of the MES system, including the overall system structure, database, functional module, system integration, etc., the development of the manufacturing management system (MES) is realized.

Physical Layer Famous Waveform Approaches for Fifth Generation Cellular Network

Many developments are taking place in the network to meet the 5G (Fifth generation) cellular network requirements; one of the very important research areas is the physical layer architecture and techniques. Studies related to the spectrum efficiency maximization indicate that the 5G air interface technology will also need to be flexible and capable of mapping various services to the best suitable combinations of frequency and radio resources.This paper investigates the physical layer waveform approaches as part of enhanced mobile broadband use case in 5G, and finds the Cyclic-Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) as a suitable approach by comparing performance parameters where the filtering and windowing can result in degradation of the quality of the signal which is measured via Error Vector Magnitude(EVM). It also attempts to enhance the down link performance between the base station and user equipment by using power amplifier clipping technique, while modelling the downlink channel by implementing channel coding, synchronization signal burst generation, different subcarrier spacing and frame numerologies for different propagation channel and different waveform approaches.

Massively Parallel, Nonlinear Processing for 6G: Potential Gains and Further Research Challenges

In order to support the plethora of the new, pending, transformative use-cases, 6G systems will need to be capable of providing not only high-throughput but also ultra-massive device connectivity. In this direction, 6G systems will need to fully exploit the available spatial, frequency and time resources of the wireless channel. Moving from linear to nonlinear processing has the potential to substantially improve the capabilities of such 6G systems. However, the processing complexity and latency requirements of traditional nonlinear processing become impractical when a large number of concurrently transmitted information streams is targeted. This work discusses how by efficiently massively parallelizing nonlinear processing, we can enable practical 6G systems with substantially improved capabilities compared to current systems. Examples of such gains are demonstrated and further research challenges are discussed towards unlocking the full potential of future massively parallel, nonlinear processing. In addition, how massively parallel, nonlinear processing can redefine the way we design future physical layer architectures is also examined.

A Survey of Candidate Waveforms for beyond 5G Systems

The 5G and beyond future wireless networks aim to support a large variety of services with increasing demand in terms of data rate and throughput while providing a higher degree of reliability, keeping the overall system complexity affordable. One of the key aspects regarding the physical layer architecture of such systems is the definition of the waveform to be used in the air interface. Such waveforms must be studied and compared in order to choose the most suitable and capable of providing the 5G and beyond services requirements, with flexible resource allocation in time and frequency domains, while providing high spectral and power efficiencies. In this paper, several beyond 5G waveforms candidates are presented, along with their transceiver architectures. Additionally, the associated advantages and disadvantages regarding the use of these transmission techniques are discussed. They are compared in a similar downlink transmission scenario where three main key performance indicators (KPIs) are evaluated. They are the peak-to-average power ratio, the overall system spectral efficiency (wherein the out of band emissions are measured, along with the spectral confinement of the power spectral density of the transmitted signals) and the bit error rate performance. Additionally, other KPIs are discussed.

Analysis and Evaluation of Cyber-attack Impact on Critical Power System Infrastructure

ABSTRACT This paper identifies and proposes two novel indices for cyber-attack impact evaluation. It focuses to create a simple common platform to compare cyber intrusion impact among different critical infrastructure using time as a base parameter. The first index is ‘Service Unavailability Cyber Impact Factor (SUCIF)’ having score range from 0 to 1, where 0 indicate cyber disaster and 1 indicates no breach. To estimate the score, detail information regarding system unavailability or malfunctioning is required. It can be used to analyze those systems whose detail cyber-physical infrastructure is not available. The second indicator named ‘Time Based Cyber Impact Factor (TBCIF)’ uses graph-based bad node detection technique to determine the score point similar to SUCIF. For this, optimal time and expected time for incursion detection plays a vital role to generate impact score. This index is suitable for test systems whose physical or cyber layer architecture is known. This research uses SUCIF index to compare hacking impact on Ukrainian Power Grid (UPG) and Saudi Aramco Oil and Gas Company (AOGC). To legitimize TBCIF score, it has been used to compare the intrusion impact of different IEEE test systems. This index is more consistent for the smart grid network.

Narrowband Internet of Things: A Comprehensive Study

Over the last decade, the number of Low-Power Wireless Access (LPWA) devices has increased remarkably. It has become crucial to introduce several LPWA technologies to share the burden of catering to the demands of these devices. Narrowband Internet of Things (NB-IoT) is one such new cellular LPWA technology which has been standardized by 3rd Generation Partnership Project (3GPP) in June, 2016. It was developed with the aim to support low-complexity and low-power devices serving areas of poor radio coverage. In this survey, we review NB-IoT technology in detail. NB-IoT’s architecture is derived from that of Long Term Evolution (LTE) cellular technology, which is another 3GPP technology. We first discuss the architectural changes made to the design of LTE to derive the design of NB-IoT, including changes in physical layer and layer-2 architecture. Next, we describe the various features introduced for NB-IoT in 3GPP Rel-13 and follow it up to describe the enhancements made in subsequent 3GPP releases until 3GPP Rel-16. Then, we review, in depth, the research work done on various aspects of NB-IoT. We follow it up with a discussion on the combination of NB-IoT with other interesting cellular technologies like Device-to-Device communication (D2D), Non-Orthogonal Multiple Access (NOMA), social IoT, and 5th Generation New Radio (5G NR). We also look into a wide variety of real-world applications of NB-IoT. Finally, we point out a few open issues of NB-IoT and identify possible future research directions.

VHDL Implementation of low power turbo coded OFDM physical layer for wireless communication

Orthogonal Frequency Division Multiplexing (OFDM) is exceptionally favored system for rapid information transmission over remote channel. In this paper, VHDL implementation of low power turbo-coded OFDM (TCOFDM) Physical layer architecture is presented. In this architecture a low power memory-less pipelined FFT processor and Log-map turbo encoder/decoders are used to provide high throughput and lower complexity. Log-map turbo decoder provides high speed with good error correction capacity, while FFT/IFFT processor with single delay feedback (SDF) memory less architecture provide improved area and power efficiency. Proposed TCOFDM system is implemented using Xilinx ISE Design suite in the simulation results shows that the proposed scheme is having low power, high speed, high throughput and smaller area in comparison to other schemes.

A New Uplink Multiple Access Based on OFDM With Low PAPR, Low Latency, and High Reliability

This paper proposes a new physical layer architecture based on orthogonal frequency-division multiplexing (OFDM) for uplink multiple access. It aims at high reliability with fixed decoder latency targeting emergent low-latency wireless applications, such as transmission of control information in machine-to-machine (M2M) and device-to-device (D2D) communications. Our proposed system is based on the judicious combination of subcarrier hopping and super-orthogonal convolutional codes for achieving high coding gain and frequency diversity, together with Golay complementary sequences for low peak-to-average power ratio (PAPR) signaling. The low PAPR nature improves the power efficiency at a power amplifier (PA) and thus contributes to the transmission range enhancement. Furthermore, by introducing non-orthogonality among users through the assignment of the same set of subcarriers to multiple users, the overall spectral efficiency can be improved. In order to suppress multiple access interference caused by the non-orthogonal overlap of users, multiuser detection (MUD) is employed. Theoretical expressions of approximate bit error rate for the proposed system with MUD are also developed. Numerical results reveal that our proposed system achieves higher reliability and higher spectral efficiency than the conventional orthogonal frequency-division multiple access (OFDMA)-based system.

High performance gain demodulate system for hybrid fiber-coaxial

Gigabit capable of Hybrid Fiber-Coaxial (HFC) represented an increase. The goals of the next generation HFC system are to efficiently utilize the precious last 100m of the coaxial cable and to achieve a Gigabit transmission rate. This target demands higher requirements regarding the physical layer (PHY) throughput. Firstly, the PHY architecture of next generation HFC system is given in detail. Secondly, in order to meet challenging high PHY throughput, a class of Low Density Parity Check (LDPC) code is selected as the Forward Error Correction (FEC) scheme, the ultimate choice is made on the basis of system with a better bit error rate performance. Finally, this paper combines the characteristics of Gray code symbol mapping for Quadrature Amplitude Modulation (QAM) constellation to design a soft decision algorithm based on signal diversity. Especially in terms of power efficiency, this algorithm can beyond the performance of log-MAP algorithm.

On the Multiband Carrier Aggregated Nonlinear LTE-A System

This paper analyzes the impact of nonlinear high power amplifiers (HPAs) on the multiband carrier aggregated (CA) long-term evolution-advanced (LTE-A) system. It is assumed that the LTE-A system consists of a multi-input-multioutput (MIMO) orthogonal frequency-division multiplexing (OFDM)-based downlink physical-layer architecture. It has been shown that the nonlinear distortion caused by HPAs can be represented in terms of a complex attenuation factor and additive zero mean Gaussian “nonlinear” noise. The closed-form generalized expressions of complex attenuation factor and variance of additive Gaussian nonlinear noise are derived that are applicable to any number of aggregated bands with any nonlinearity order and memory depth. From these expressions, the overall performance of a multiband CA-MIMO-OFDM system in terms of symbol error rate and error vector magnitude for M-ary quadrature amplitude modulation (M-QAM) has been evaluated. We also investigate the combined effect of a number of aggregated bands, input-back off, and diversity gain on the performance of a CA-MIMO-OFDM system. It is observed that diversity gain can improve the performance of CA-MIMO-OFDM in low signal-to-noise ratio (SNR) region. However, in the high SNR region, there is no substantial effect of increasing diversity on the performance. A good agreement between the analytical and simulation results in the multipath Rayleigh fading channel validates the theoretical results obtained in this paper.

Licensed-Assisted Access LTE: coexistence with IEEE 802.11 and the evolution toward 5G

LAA is a new operation mode of LTE in the unlicensed spectrum, which will be featured in LTE Release 13. Under LAA, licensed carriers will be aggregated with unlicensed carriers in order to opportunistically enhance downlink user throughput while still offering seamless mobility support. In order to coexist with WiFi, some of the new functionalities required of LAA LTE include a mechanism for channel sensing based on listen-before-talk, discontinuous transmission on a carrier with limited maximum transmission duration, and multicarrier transmission across multiple unlicensed channels. This article presents a detailed overview of the design agreements for LAA, the impact of unlicensed spectrum operation on the LTE physical layer architecture, and the scope of additional enhancements beyond LTE Release 13. A range of simulations for indoor and multicarrier scenarios show that fair coexistence between LAA and WiFi can be achieved, and that deployment of LAA can provide a boost in WiFi performance.

FPGA-Based Realisation of SDR with OFDM Tranceiver

Software-defined radio architecture is the key point of next generation communication systems in which some of the functional units are designed as software on a reconfigurable processor. This paper proposes the physical layer architecture of SDR with modified orthogonal frequency division multiplexing (OFDM). One of the main drawbacks of OFDM is that its high peak-to-average reduction (PAPR) ratio. The PAPR can be reduced using filtering and adaptive peak windowing method with Kaiser window. The adaptive window method finds the positions of maximum peak values using a peak detector in the signal and applies the window function with variable parameter. The radix 2 scalable N point FFT algorithm is used in the system. The mapping of the information signal is done with BPSK, PSK, and 16 QAM modulation. According to the signal-to- noise ratio (SNR) value, the type of modulation can be selected. Decoding of the OFDM signal in the receiver is done with Viterbi decoding algorithm. The communication system simulation is done in MATLAB and the baseband operations are implemented on Xilinx FPGA. Defence Science Journal, Vol. 65, No. 3, May 2015, pp.233-239, DOI: http://dx.doi.org/10.14429/dsj.65.6011

Peak Power and Crest Factor Reduction in OFDM Transceiver Using Filtering Method for SDR Application

The software defined radio is used as a Transceiver system for next generation wireless communication system. The physical layer architecture is presented in this paper. High peak to power average ratio/crest factor is the main challenge of the orthogonal frequency division multiplexing modulation techniques. Here windowing technique with adaptive filtering is applied for the transmitted signal to reduce the power. The black Mann window is used for this purpose. The mapping/de-mapping of signal in the transmitter and receiver is done with various types of modulation. The proposed system requires only one IFFT block for sampling the signals. The existing method such as clipping and filtering gives fare result but there is a chance of losing the peak values of the signal. This issue can be overcome by proposed method. The comparison of power, crest factor and bit error ratio has been taken in MATLAB. This architecture can be done on reconfigurable field programmable gate array.

Next generation elastic optical networks: The vision of the European research project IDEALIST

In this work we detail the strategies adopted in the European research project IDEALIST to overcome the predicted data plane capacity crunch in optical networks. In order for core and metropolitan telecommunication systems to be able to catch up with Internet traffic, which keeps growing exponentially, we exploit the elastic optical networks paradigm for its astounding characteristics: flexible bandwidth allocation and reach tailoring through adaptive line rate, modulation formats, and spectral efficiency. We emphasize the novelties stemming from the flex-grid concept and report on the corresponding proposed target network scenarios. Fundamental building blocks, like the bandwidth-variable transponder and complementary node architectures ushering those systems, are detailed focusing on physical layer, monitoring aspects, and node architecture design.

Fine-Grained Channel Access in Wireless LAN

With the increasing of physical-layer (PHY) data rate in modern wireless local area networks (WLANs) (e.g., 802.11n), the overhead of media access control (MAC) progressively degrades data throughput efficiency. This trend reflects a fundamental aspect of the current MAC protocol, which allocates the channel as a single resource at a time. This paper argues that, in a high data rate WLAN, the channel should be divided into separate subchannels whose width is commensurate with the PHY data rate and typical frame size. Multiple stations can then contend for and use subchannels simultaneously according to their traffic demands, thereby increasing overall efficiency. We introduce FICA, a fine-grained channel access method that embodies this approach to media access using two novel techniques. First, it proposes a new PHY architecture based on orthogonal frequency division multiplexing (OFDM) that retains orthogonality among subchannels while relying solely on the coordination mechanisms in existing WLAN, carrier sensing and broadcasting. Second, FICA employs a frequency-domain contention method that uses physical-layer Request to Send/Clear to Send (RTS/CTS) signaling and frequency domain backoff to efficiently coordinate subchannel access. We have implemented FICA, both MAC and PHY layers, using a software radio platform, and our experiments demonstrate the feasibility of the FICA design. Furthermore, our simulation results show FICA can improve the efficiency of WLANs from a few percent to 600% compared to existing 802.11.

A Survey of Digital Television Broadcast Transmission Techniques

This paper is a survey of the transmission techniques used in digital television (TV) standards worldwide. With the increase in the demand for High-Definition (HD) TV, video-on-demand and mobile TV services, there was a real need for more bandwidth-efficient, flawless and crisp video quality, which motivated the migration from analogue to digital broadcasting. In this paper we present a brief history of the development of TV and then we survey the transmission technology used in different digital terrestrial, satellite, cable and mobile TV standards in different parts of the world. First, we present the Digital Video Broadcasting standards developed in Europe for terrestrial (DVB-T/T2), for satellite (DVB-S/S2), for cable (DVB-C) and for hand-held transmission (DVB-H). We then describe the Advanced Television System Committee standards developed in the USA both for terrestrial (ATSC) and for hand-held transmission (ATSC-M/H). We continue by describing the Integrated Services Digital Broadcasting standards developed in Japan for Terrestrial (ISDB-T) and Satellite (ISDB-S) transmission and then present the International System for Digital Television (ISDTV), which was developed in Brazil by adopteding the ISDB-T physical layer architecture. Following the ISDTV, we describe the Digital Terrestrial television Multimedia Broadcast (DTMB) standard developed in China. Finally, as a design example, we highlight the physical layer implementation of the DVB-T2 standard.

Optimization of high-definition video coding and hybrid fiber-wireless transmission in the 60 GHz band

The paper addresses the problem of distribution of high-definition video over fiber-wireless networks. The physical layer architecture with the low complexity envelope detection solution is investigated. We present both experimental studies and simulation of high quality high-definition compressed video transmission over 60 GHz fiber-wireless link. Using advanced video coding we satisfy low complexity and low delay constraints, meanwhile preserving the superb video quality after significantly extended wireless distance.

UHF RFID Reader Implementation for EPC C1G2 Protocol

UHF RFID system has been mainly used in logistics,production and supply chain management. The implementation of UHF RFID reader with excellent performance is still challenging. This paper presents a UHF RFID reader implementation for EPC C1G2 protocol. EPC C1G2 physical layer architecture and some critical modules like encoder ,decoder, modulator and demodulator are described in details. All modules are verified in FPGA and the experiments demonstrate that the designed RFID reader baseband system could perform well.

A New Physical Layer Capable of Record Gigabit Transmission Over 1 mm Step Index Polymer Optical Fiber

In this paper we present the latest results from the POF-PLUS EU Project, demonstrating record transmission of a Gigabit Ethernet compliant stream over 75m of 1mm PMMA SI-POF with 2.5 dB system margin, and over 50 m with 7 dB system margin, in both cases using commercial RC-LED. We believe this is an unprecedented results, showing for the first time that the target distance of 50 meters is reachable with a large system margin. The results were made possible by a careful optimization of the physical layer architecture, which is explained in detail in this paper. The system is experimentally demonstrated over realistic digital stream at the transmitter and real time processing at the receiver.

Fine-grained channel access in wireless LAN

Modern communication technologies are steadily advancing the physical layer (PHY) data rate in wireless LANs, from hundreds of Mbps in current 802.11n to over Gbps in the near future. As PHY data rates increase, however, the overhead of media access control (MAC) progressively degrades data throughput efficiency. This trend reflects a fundamental aspect of the current MAC protocol, which allocates the channel as a single resource at a time. This paper argues that, in a high data rate WLAN, the channel should be divided into separate subchannels whose width is commensurate with PHY data rate and typical frame size. Multiple stations can then contend for and use subchannels simultaneously according to their traffic demands, thereby increasing overall efficiency. We introduce FICA, a fine-grained channel access method that embodies this approach to media access using two novel techniques. First, it proposes a new PHY architecture based on OFDM that retains orthogonality among subchannels while relying solely on the coordination mechanisms in existing WLAN, carrier-sensing and broadcasting. Second, FICA employs a frequency-domain contention method that uses physical layer RTS/CTS signaling and frequency domain backoff to efficiently coordinate subchannel access. We have implemented FICA, both MAC and PHY layers, using a software radio platform, and our experiments demonstrate the feasibility of the FICA design. Further, our simulation results suggest FICA can improve the efficiency ratio of WLANs by up to 400% compared to existing 802.11.