Coverage Range Analysis and Performance Evaluation of Wireless Technologies in Industrial Channel Conditions

Wireless technologies gain importance in various fields of industrial communication as they facilitate control and data acquisition tasks. In this context, Parallel Sequence Spread Spectrum (PSSS) is a promising new approach. The parametrization of a PSSS system is very flexible and thus can be precisely adapted to the application's requirements. Independent of the PSSS parametrization, the transmission resources can be assigned efficiently since their management is very flexible. With full duplex and a resource stream in both up- and downlink, even a network with high node density and varying QoS requirements can be served in a single PSSS system. Especially cycle times smaller than 1 ms are possible. A PSSS system for ultra low latency and highly reliable industrial applications is parametrized in the German research project ParSec. In ParSec, the PSSS system is evaluated analytically as well as in practice. In order to allow early measurements, in ParSec a rapid prototype system was developed, with which first PSSS measurements were performed. This paper gives an overview of the fundamental PSSS concept, while it points out the overall system's potential in industrial communication. Moreover, the measurement results are discussed to evaluate the bit error distribution in a PSSS frame. Rolf Kraemer IHP Microelectronics Frankfurt (Oder), Germany.

In this paper we investigate the use of bipolar Barker sequences for high-speed wireless communication systems based on Parallel Sequence Spread Spectrum (PSSS) modulation. To improve bit error rate (BER) performance for PSSS, we propose the use of either median detection at the receiver or DC-offset correction at the transmitter. Both techniques cancel the influence of cyclic-autocorrelation sidelobes that occur in the correlator at the receiver. The simulation results reveal that PSSS based on Barker codes of length 13 outperforms PSSS with m-sequences by 2.5 dB, if one of the abovementioned techniques is applied. The novelty of the proposed DC-correction method lies in a simple hardware realization and very low complexity. All modifications are performed in the PSSS transmitter, which is significantly less complex than the PSSS receiver. Thus, this algorithm improves PSSS BER and keeps the balance between the transmitter and receiver complexity.

Parallel sequence spread spectrum (PSSS) is a versatile spreading technique suitable for high-speed wireless communication. We are aiming for transmission rates up to 100 Gbps in the terahertz frequency band. Here, we propose a novel transmitter architecture comprising of 15 parallel PSSS encoders used in conjunction with a high-speed analog multiplexer (MUX) and DACs. In our design, PSSS encoders (with 4 bit/sIHz spectral efficiency) and DACs operate a low symbol frequency of 1.67 GHz wherein the analog MUX runs at a chip rate of 30 GHz to achieve 100 Gbps. Our scheme is based on a parallel PSSS encoding of the input signal using an analog MUX to process the parallel output results. To demonstrate the potential of a parallel PSSS encoding, we verified the transmitter architecture on Virtex ultrascale FPGA (VCD108) and implemented the design on GlobalFoundries 28 nm FDSOI technology, showing a PSSS symbol rate of 1.785 GHz to achieve above 100 Gbps. The transmitter design of 15 parallel encoders occupies a chip area of 0.0073 mm2with a power consumption of 20.882 mW and has an energy efficiency of 0.21 p.j/bit

Most organizations today have a set of key performance indicators (KPIs) that are used for decision-making. Because a balanced scorecard approach has been widely adopted, typically KPIs have moved beyond the basic financial metrics. However, developing the right set of KPIs is an important step in promoting continuous improvement and overall business success. Organization that implement six sigma or lean six sigma have a built-in set of KPIs, such as defects, ppm defective, process yields, process cycle times, and a variety of inventory statistics, such as WIP inventory. But I don't think this goes far enough in most situations. KPIs should be traceable to customer satisfaction, both for external customers and internal ones. Organizations should formalize customer requirements and then evaluate how they are doing with respect to this list when they conduct strategic planning sessions. This is a good way to develop the right KPIs. However, overemphasis on short-term financial results can skew this process. Too much focus on quarterly growth in sales or revenue and deflect attention from the issues that contribute to long-term business growth and success. Organizations often gravitate towards collecting data that is easy to obtain, but may not be necessarily useful. An example is information about customer satisfaction data. Surveys can be useful, but may not tell the complete story. One organization that I am familiar with has a customer service line. They reported very few serious complaints from that source. Analysis revealed that the average waiting time for customers that used this line was in excess of 30 minutes. Furthermore, the ability of the system to place calls on hold was limited, so a significant number of calls were “blocked”; that is, they were not answered at all. So the volume of customer issues that this service was designed to serve was dramatically underestimated. Some KPIs are lagging indicators of business performance. Examples include sales volumes and maintenance expenses. These are usually easy to generate, but may not provide much indication of future success. Reliable forecasts of future demand (demand isn't necessarily the same as sales) is usually a better business indicator. Leading indicators are harder to devise, almost always depend on the specific nature of the individual organization, and may be difficult to generate. For example, cycle time for new product introduction is often a critical measure of future business success in many industries. If this KPI is unsatisfactory or is getting longer for unexplained reasons it may indicate an area for lean six sigma intervention. Performance measurement is an important management tool for evaluating and improving organizational success. Leading KPIs can be an effective “canary in the coal mine” warning of impending trouble. The investment required to develop and maintain the correct set of KPIs will pay many dividends.

Deployment of wireless sensor networks (WSNs) with a large number of nodes have reinstated interest in spread spectrum (SS) technologies as they allow to establish multiple access for nodes with simple hardware and limited power budget. Chaotic spreading is one of the still insufficiently explored areas which can lead to higher security and lower multiple access interference (MAI). This research is intended to bring new information about the performance of binary direct sequence spread spectrum (DSSS) and frequency hopping spread spectrum (FHSS) communication systems which employ chaos-based spreading codes and compare them against classical systems employing m-sequences. Unlike existing research, this investigation is based on the simulation of passband communication systems with up/down-conversion and respective filtering. Performance comparison in terms of bit error ratio (BER) versus signal-to-noise ratio (SNR) at the different number of users and MAI dependence on carrier frequency offset among users in case of additive white Gaussian noise (AWGN) channel are presented. Obtained results highlight several scenarios where chaotic-sequences-based binary DSSS and FHSS systems have advantages over classical solutions.

Frequency Hopping Spread Spectrum (FHSS) system is often deployed to protect wireless communication from jamming or to preclude undesired reception of the signal. Such themes can only be achieved if the jammer or undesired receiver does not have the knowledge of the spreading code. For this reason, unencrypted M-sequences are a deficient choice for the spreading code when a high level of security is required. The primary objective of this paper is to analyze vulnerability of linear feedback shift register (LFSRs) codes. Then, a new method based on encryption algorithm applied over spreading codes, named hidden frequency hopping is proposed to improve the security of FHSS. The proposed encryption security algorithm is highly reliable, and can be applied to all existing data communication systems based on spread spectrum techniques. Since the multi-user detection is an inherent characteristic for FHSS, the multi-user interference must be studied carefully. Hence, a new method called optimum pair “key-input” selection is proposed which reduces interference below the desired constant threshold.

Parallel Sequence Spread Spectrum (PSSS) is a physical layer (PHY) base band technology. It was selected for the wireless sensor network standard IEEE802.15.4-2006, in order to increase data rate and radio performance in fading channels for frequency bands below 1GHz. In the work presented in this paper PSSS is used for the first time in the 60 GHz ISM Band to achieve ultra-high transmission speed similar to IEEE802.11ad but at lower receiver complexity. A different encoding scheme than for IEEE802.15.4-2006 has been applied to improve the coverage range of the 60 GHz radio. Using an available 60GHz heterodyne radio we achieved a measured data rate of 4Gb/s at a distance of 3 m using a simple Vivaldi antenna. The signal processing was performed off-line using a Matlab implementation in a "Hardware in the Loop" approach. Furthermore we will outline the architecture of a mixed-signal (analog/digital) baseband processor that reduces the implementation complexity by at least one order of magnitude. This will result both in lower power dissipation as well as lower Silicon area consumption.

A three-level slicing algorithm in a multi-slice multi-numerology context

Contemporary wireless communication strategies focus on efficient use of bandwidth in order to allow more users to exploit the RF spectrum through techniques like Frequency-hopping spread spectrum (SS) and Direct-sequence SS. In many real-world applications, these methods are implemented for synchronous communication systems. To achieve synchronous communication, two-way handshaking that requires overhead circuitry is performed between the sender and receiver. In order to use spread spectrum methods for certain unconstrained and low-power applications, such as implantable and remote monitoring devices, it is necessary to refine these methods to support asynchronous communication. We have designed and modeled a SS system, which could be integrated with a custom integrated circuit that would provide elementary multi-user communication. The SS logic generates a gold-code based on address and data bits that is then modulated with a carrier to transmit the information. Because the system is asynchronous, we treat each transmitted code as an independent piece of information. The receiver decodes the information using a full correlation with the ideal known gold-codes. For efficiency purposes, the filter is applied in the frequency domain. A threshold is applied to the output of the filter to determine if a particular code is transmitted as well as the point in time/space from which the signal was sent. The method was simulated and evaluated under several scenarios including different carrier frequencies, multiple targets, and various positions relative to the receiver from the simulated receiver. The results demonstrate the utility of asynchronous SS under many different conditions.

Error correction coding techniques significantly improve performance of spread spectrum communication systems in environments containing jamming, multipath, and unregulated multiple access. This paper investigates the optimization of spread spectrum system performance for time-varying unknown interference. Noncoherent frequency hopping (FH) spread spectrum modulation, and hybrid FH-PN incorporating a direct sequence PN modulation on each hopped frequency are studied. For FH or FH-PN, the data modulations considered are differential phase-shift-keying (DPSK), differential quadriphase-quadriphase-shift-keying (DQPSK), and multiple-frequency-multiple-frequency-shift-keying (MFSK). Both block and convolutional error correction coding techniques are studied as a means of improving the spread spectrum performance.

Recently, ultra wideband (UWB) communications have received increasing interest due to the high data rate achievable in a short distance. UWB communications can have strong interference mitigation capability. A multicarrier ultra wideband (MC-UWB) system has been introduced in (A.H. Tewfik, et al., (2002)) and (E. Saberinia, et al., (2002)). In the MC-UWB communication systems, multiple symbols are transmitted over different carriers simultaneously. The same symbol is retransmitted over different frequency bands by utilizing frequency hopping (FH) techniques. Frequency hopping and multicarrier technologies smooth the average power spectrum density of the system. In this paper, the expression of the power spectrum density of the MC-UWB system is derived. The radiated emission power for UWB communication systems is limited by the spectrum mask specified by wireless communication authorities, such as the federal communications commission (FCC) in United States. Different parameters in the MC-UWB system will have different effects on the power spectrum density and the maximal achievable data rate. The analysis of impact of parameters in the system on the power spectrum density will help the system designer select proper parameter set to fit in emission power regulation and the required data rate in practical UWB systems. Some examples of parameter selection are also given to illustrate the impact of different parameters in the system on the power spectrum density.

Random codekey selection using codebook without pre-shared keys for anti-jamming in WBAN

Technological innovation is profoundly transforming industrial production, notably through automated systems like robotic production lines. To harness their full potential, effective monitoring and evaluation are essential, facilitated by Key Performance Indicators (KPIs). This study conducts a thorough analysis of KPIs within industrial automation, focusing on a robotic production line assembling heat exchangers for refrigeration equipment. The aim is to measure, evaluate, and optimize performance in a smart, adaptable manner, creating a robust database that is not currently available as intended. Identified KPIs include standards such as cycle time, utilization, efficiency, and tailor-made metrics for this application, aligning with Industry 4.0 principles and sustainable manufacturing by monitoring energy and resource consumption as well. A granular data analysis approach captures the daily performance of each robot, enabling comprehensive assessment. Operational, daily, and line-level indicators provide insights into specific improvement areas. The methodology’s scalability allows for easy adaptation to larger production lines, highlighting its versatility and potential applicability across various industrial settings. By proposing a granular and scalable KPIs framework, this research underscores the critical role of detailed performance monitoring in industrial robotics, driving continuous improvement and innovation while enhancing operational efficiency and competitiveness, in an ever-growing landscape of automated manufacturing environments.

We propose a closed-loop industrial radio system with a star topology for factory automation using Parallel Sequence Spread Spectrum (PSSS) technology. This system implements all significant concepts for synchronization, duplex-communication, channel estimation/equalization based on an innovative transceiver concept. The industrial environment tends to have non-line of sight channels that lead to RMS delay spreads of less than 100 ns. Here, we propose a channel equalization scheme to compensate for these delay spreads. Another challenging aspect is the implementation of a code division duplexing (CDD) scheme. We propose a closed-loop system architecture that can achieve the targets set by Industry 4.0 bodies such as IWSAN. This paper gives an overview of the closed-loop systems concept.

In this paper, we discuss the main challenges and our solutions proposed for implementation of a high-speed data link layer processor. Our target is to achieve processing throughput faster than 20 Gbps. Meanwhile a single core of our implementation achieves ''only'' ~28 Gbps, we propose a multi-core solution that can run up to ~110 Gbps. For this purpose, we use baseband signal splitters and combiners. Alternatively, we come up with Parallel Sequence Spread Spectrum (PSSS). After splitting the input signal, we divide the required processing-effort among a set of parallel baseband and data link layer processors. The discussed data link layer processor uses hybrid-automatic-repeat-request-I (HARQ-I) with link adaptation and selective fragment repetitions. Such solution significantly improves the efficiency of the method and allows to reduce the implementation complexity when compared to HARQ-III. The main issue discussed in the article is power and energy consumption. Our solution consumes maximally 300 mW at 27.9 Gbps, including forward error correction (FEC) engine.