Signal space diversity for improving the reliability performance of OFDM with subcarrier power modulation

As the demand for higher data rates continues to increase exponentially, there is a shift towards exploring contemporary techniques that are likely to offer higher spectral efficiency. A new modulation technique termed as orthogonal frequency division multiplexing with sub‐carrier power modulation (OFDM‐SPM) has recently been introduced. It is an original technique that is still largely under-explored and aims at transmitting more bits per sub‐carrier by manipulating the power of the sub‐carriers in an OFDM block, in addition to those bits that are usually transmitted by conventional modulation schemes such as M-PSK. During the investigation and theoretical testing stages, it was found that the additional data stream conveyed by subcarriers' power has higher bit error rate (BER) performance compared to the data stream conveyed by conventional modulation schemes. To overcome this shortfall, signal space diversity (SSD) along with coordinate interleaving is proposed in this work to be integrated with OFDM‐SPM to help improve the overall BER performance. By doing so, it is shown that a BER performance of 10-3 can be obtained at SNR of 15 dB, which means achieving an improvement of more than 5 dB compared to the case of using OFDM‐SPM without SSD. Furthermore, the performance results of OFDM‐SPM‐SSD is compared with those of OFDM‐SPM with maximal ratio combining (MRC) and the obtained results show that OFDM‐SPM‐SSD offers superior performance. Additionally, a study of the effect of the constellation rotation on OFDM‐SPM is provided and an in‐depth analysis is also carried out for different power polices of sub‐carrier power modulation with regards to two main performance metrics; namely BER and the throughput. Simulation results show that SSD provides a considerable improvement in the BER over both plain OFDM‐SPM and OFDM‐SPM‐MRC. The analysis also reveal that when considering the different power policies of SPM, the BER results are optimum in the case of using power‐reassignment policy.No sponso

The Predictors of SMEs and In-House Recovery of Pandemic: Employees’ Perspective Toward Challenges, Drivers and Government Responses from Jordan Context

Purpose: This study seeks to provide evaluations of the challenges, drivers and government responses that are provided for SEMs and in-house recovery in Jordan context in time of COVID-19, from viewpoints of owners and employees of SMEs and in-house businesses.   Theoretical framework: This study reviews the literature for the challenges, drivers and government responses for SMEs to assemble the list that was used to gather respondents’ evaluations and provide an evaluation of the SME environment in Jordan during the COVID-19 pandemic.   Design/Methodology/Approach: Using a questionnaire, data was collected for this study, purposive sampling was applied, and a sample of 1,179 provides the assessments that were used to gather the results. SPSS was used to conduct data analysis that was based on the use of descriptive analysis.   Findings: The findings show that owners and employees of SMEs and in-house businesses in Jordan express moderate levels of agreement toward all proposed challenges, with the exception of challenges related to market factors, which are at a high level of agreement. Additionally, all proposed drivers are at moderate levels of agreement, and the highest agreement level is for e-marketing factors.   Research practical & Social implications: The study suggests allowing government agencies, educational institutions, donor and support organisations, and owners and employees of SMEs to adopt strategic business plans that take advantages of possible drivers and mitigate the consequences of challenges in the business environment.   Originality/Value: This study contributes to the emerging literature concerning SMEs during the COVID-19 pandemic by targeting owners and employees of SMEs and in-house businesses in Jordan to gather their responses regarding a set of challenges, drivers and government responses that the literature proposed as characterising the business environment during the pandemic

STRESS TESTING MQTT SERVER FOR PRIVATE IOT NETWORKS

The rapid development of the Internet of Things (IoT) and the wide area of application rise the IoT concept to be the future of the internet. Indeed, IoT environment has a special nature with a lot of constraints in term of resource consumption. Moreover, the data exchanged between things and the internet is big data. In order to achieve efficiency in IoT communication, many technologies and new protocols based on these technologies have been developed. This paper aims to study the performance of Message Queuing Telemetry Transport (MQTT) by implementing this protocol on test-bed network infrastructure and analyzing the performance properties such as delay jitter, packet loss and throughput for real time and non-real time scenarios. Finally, future research issues in MQTT protocol are suggested

STRESS TESTING MQTT SERVER FOR PRIVATE IOT NETWORKS

The rapid development of the Internet of Things (IoT) and the wide area of application rise the IoT concept to be the future of the internet. Indeed, IoT environment has a special nature with a lot of constraints in term of resource consumption. Moreover, the data exchanged between things and the internet is big data. In order to achieve efficiency in IoT communication, many technologies and new protocols based on these technologies have been developed. This paper aims to study the performance of Message Queuing Telemetry Transport (MQTT) by implementing this protocol on test-bed network infrastructure and analyzing the performance properties such as delay jitter, packet loss and throughput for real time and non-real time scenarios. Finally, future research issues in MQTT protocol are suggested

Methods for SARS-CoV-2 hospital disinfection, in vitro observations.

This work was funded by National Health Service Grampian Charity. DECL received support from UK Biotechnology and Biological Sciences Research Council and the USA National Science Foundation (BB/W002760/1). Acknowledgment We thank John Ellison for provision of the je2Care 222nm UVC Lamp, and Novus ltd for access to the EORG water ozonation unit.Peer reviewedPublisher PD

Localizing Sustainable Development Goals in Strategic Development Planning Procedures. Case Study: Local Development Planning Manual for the Palestinian Cities and Towns

This study aimed to localize the Sustainable Development Goals (SDGs) in the Palestinian development goals on local level. For this purpose, the study adopted a methodology that includes proposed mechanisms to localize these goals and their derived objectives in the development planning of Palestinian cities and towns to link it to global development. In addition to a proposal for a methodology that includes a set of technical tools to support and ensure the integrated implementation of global agendas at the local level. This mechanism proposes modifications to the current procedures used in the planning process in the Palestinian context and the adoption of new tools, each of which is specific to a specific stage, in a way that can be applied according to the individual needs and demands of each particular community. The proposed mechanisms included modifications to the elements and steps of the five phases included in the Palestinian Guide to Local Strategic Development Planning. The study also included the application of the proposed methodology to a case study, the strategic development plan for the city of Nablus. In light of the findings of the study, a number of recommendations were presented to decision-makers to take in order to localize the sustainable development goals in Palestinian development planning on local level

Increases in Heart Rate Variability Signal Improved Outcomes in Rapid Response Team Consultations: A Cohort Study

Background. Reduced heart rate variability (HRV) indicates dominance of the sympathetic system and a state of “physiologic stress.” We postulated that, in patients with critical illness, increases in HRV might signal successful resuscitation and improved prognosis. Methods. We carried out a prospective observational study of HRV on all patients referred to the rapid response team (RRT) and correlated with serial vital signs, lactate clearance, ICU admission, and mortality. Results. Ninety-one patients were studied. Significantly higher HRV was observed in patients who achieved physiological stability and did not need ICU admission: ASDNN 19 versus 34.5, p=0.032; rMSSD 13.5 versus 25, p=0.046; mean VLF 9.4 versus 17, p=0.021; mean LF 5.8 versus 12.4, p=0.018; and mean HF 4.7 versus 10.5, p=0.017. ROC curves confirmed the change in very low frequencies at 2 hours as a strong predictor for ICU admission with an AUC of 0.772 (95% CI 0.633, 0.911, p=0.001) and a cutoff value of −0.65 associated with a sensitivity of 78.6% and a specificity of 61%. Conclusions. Reduced HRV, specifically VLF, appears closely related to greater severity of critical illness, identifies unsuccessful resuscitation, and can be used to identify consultations that need early ICU admission