Waveform Design for 5G and Beyond

5G is envisioned to improve major key performance indicators (KPIs), such as peak data rate, spectral efficiency, power consumption, complexity, connection density, latency, and mobility. This chapter aims to provide a complete picture of the ongoing 5G waveform discussions and overviews the major candidates. It provides a brief description of the waveform and reveals the 5G use cases and waveform design requirements. The chapter presents the main features of cyclic prefix-orthogonal frequency-division multiplexing (CP-OFDM) that is deployed in 4G LTE systems. CP-OFDM is the baseline of the 5G waveform discussions since the performance of a new waveform is usually compared with it. The chapter examines the essential characteristics of the major waveform candidates along with the related advantages and disadvantages. It summarizes and compares the key features of different waveforms.Comment: 22 pages, 21 figures, 2 tables; accepted version (The URL for the final version: https://onlinelibrary.wiley.com/doi/abs/10.1002/9781119333142.ch2

Energy and spectral-efficient lens antenna subarray design in MmWave MIMO Systems

Lens antenna subarray (LAS) is one of the recently introduced technologies for future wireless networks that significantly improves the energy efficiency of multiple-input multiple-output (MIMO) systems while achieving higher spectral efficiency compared to single-lens MIMO systems. However, a control mechanism for the LAS-MIMO design is considered a challenging task to efficiently manage the network resources and serve multiple users in the system. Therefore, in this paper, a sub-grouped LAS-MIMO architecture along with a hybrid precoding algorithm are proposed to reduce the cost and hardware overhead of traditional hybrid MIMO systems. Specifically, the LAS structure is divided into sub-groups to serve multiple users with different requirements, and an optimization problem based on the achievable sum-rate is formulated to maximize the spectral efficiency of the system. By splitting the sum-rate problem into sub-rate optimization problems, we develop a low-complexity hybrid precoding algorithm to effectively control the proposed architecture and maximize the achievable sum-rate of each subgroup. The proposed precoding algorithm selects the beam of each lens from a predefined set within a subgroup that maximizes the subgroup sum-rate, while the phase shifters and digital precoders in each subgroup are computed independently. The link between subgroups is updated based on successive interference cancelation to minimize interference between users of different subgroups. Our analysis and simulation results show that the proposed precoding algorithm of the sub-grouped LAS-MIMO architecture performs almost as well as traditional fully-connected hybrid MIMO systems in terms of spectral efficiency at low and high signal-to-noise ratio (SNR). It also outperforms traditional fully-connected and sub-connected hybrid MIMO systems in terms of energy efficiency, even when a large number of lenses are employed.National Science Foundation (NSF

Effect of Location Accuracy and Shadowing on the Probability of Non-Interfering Concurrent Transmissions in Cognitive Ad Hoc Networks

Cognitive radio ad hoc systems can coexist with a primary network in a scanning-free region, which can be dimensioned by location awareness. This coexistence of networks improves system throughput and increases the efficiency of radio spectrum utilization. However, the location accuracy of real positioning systems affects the right dimensioning of the concurrent transmission region. Moreover, an ad hoc connection may not be able to coexist with the primary link due to the shadowing effect. In this paper we investigate the impact of location accuracy on the concurrent transmission probability and analyze the reliability of concurrent transmissions when shadowing is taken into account. A new analytical model is proposed, which allows to estimate the resulting secure region when the localization uncertainty range is known. Computer simulations show the dependency between the location accuracy and the performance of the proposed topology, as well as the reliability of the resulting secure region

Relative Odds of Neck Pain to Helmet Use Among Motorcyclists: a Case-Control Study

Background: Neck pain is a widespread problem among motorcyclists, which is often neglected. There is limited research on the motorcycle's ergonomics, particularly in the context of the interaction between the riders and motorcycle. Motorcycle helmets have proven to increase the weight on the neck, thus causing more burdens which can lead to neck pain. Methodology: Case-Control study design was opted to measure the relative odds of neck pain in relation to the helmet use as an exposure. A total of 260 (mean age of 22.58 ± S.D. 1.95 years) undergraduate students were selected using purposive sampling. The case to control ratio was 1:4 (54 Cases and 206 Controls) where cases were defined as the motorcyclists having neck pain with a riding experience of more than one year. The neck pain and disability scale were obtained using a self-administered questionnaire. Chi-square and binary logistic regression were used to calculate the significant relationship and odds of neck pain amongst motorcyclists with and without helmet use. Results: The study results showed that out of 260 motorcyclists, 190 (73.1%) were helmet users, and 54 (20.8%) had neck pain, 70 (27.9%) helmet users had a neck pain prevalence of 11 (4.2%). The relative odd to have neck pain was 2.13 times more amongst the motorcyclists using the helmet as compared to that of non-helmet users. The logistic regression results showed significant results (P < 0.05) with regards to the BMI, helmet weight and duration of helmet use but did not show a significant relation with average motorcycle use per day unless it exceeded 70 kilometres. Conclusion: Use of helmet can be a potential cause of neck pain amongst motorcyclist users but the odds to have neck pain enhance with the increase in motorcycle use per day. The protective benefits are multi-fold for helmet use which outreaches the negative impact, including neck pain amongst motorcyclists

The technical and economic efficiency analyses of performance of brown trout (Salmo trutta fario l., 1758) fed by the commercial diets enriched with different levels of linolenic acid (lna; 18:3 n-3)

This study was designed to determine the technical and economic efficiency levels of the commercial basal feeds enriched with 10%, 5% and 0% rates of LNA (LNA10, LNA5 and LNA0) on the growth performance of brown trout by analyzing the marginal factor cost (MFC) and the marginal revenue of physical product (MRPP). A total of 300 brown trout with an initial individual weight of 4±0.05 g were randomly divided in 12 cages (25 fingerlings in each cage), and kept under 24L:0D (light/dark) photoperiod condition for 9 weeks treated by LNA10, LNA5 and LNA0. The results of the study showed that LNA0 and LNA10 of the effective feed sources, respectively on the growth performance of brown trout were more suitable to produce as the homogeneous products for the consumers and differentiated those for the drug industry in view of the economic and technical efficiencies

Combined numerical-experimental framework for strain based design and flaw assessment of girth welds

An increasing number of transmission pipelines have to be installed and operated in harsh conditions, due to the diminishing reserves of exploited fossil fuel sources. Under certain environment related circumstances, longitudinal plastic strains are imposed. When tensile, these may induce failure in girth welds in conjunction with the inevitable presence of weld defects. A large number of factors related to environment, material, geometry and operating conditions influence the tensile strain capacity and, hence, the acceptability of girth weld flaws. Therefore, a project specific development of guidelines in this strain based context is recommended. This paper provides systematic frameworks on (a) how to design pipelines under strain based conditions, and (b) how to assess girth weld flaws that were detected using non destructive testing. Attention is given to several technical and economical aspects related to the selection and qualification of pipe and weld metals, and to the evaluation of flaw acceptability. Both frameworks comprise a combined experimental-numerical approach, collecting project development reports from literature with research carried out at Soete Laboratory. Concretely, four in-house realizations are adopted: the UGent equation for strain capacity, the curved wide plate tension test, the UGent stress-strain equation and a finite element model of full scale pressurized pipe tension testing. The proposed frameworks aim to facilitate in performing thorough and economically justifiable strain based design and assessment processes

Spectrum Sensing for Cognitive Radio Systems Through Primary User Activity Prediction

Traditional spectrum sensing techniques such as energy detection, for instance, can sense the spectrum only when the cognitive radio (CR) is is not in operation. This constraint is relaxed recently by some blind source separation techniques in which the CR can operate during spectrum sensing. The proposed method in this paper uses the fact that the primary spectrum usage is correlated across time and follows a predictable behavior. More precisely, we propose a new spectrum sensing method that can be trained over time to predict the primary user's activity and sense the spectrum even while the CR user is in operation. Performance achieved by the proposed method is compared to classical spectrum sensing methods. Simulation results provided in terms of receiver operating characteristic curves indicate that in addition to the interesting feature that the CR can transmit during spectrum sensing, the proposed method outperforms conventional spectrum sensing techniques

Visualization on colour based flow vector of thermal image for movement detection during interactive session

Recently thermal imaging is exploited in applications such as motion and face detection. It has drawn attention many researchers to build such technology to improve lifestyle. This work proposed a technique to detect and identify a motion in sequence images for the application in security monitoring system or outdoor surveillance. Conventional system might cause false information with the present of shadow. Thus, methods employed in this work are Canny edge detector method, Lucas Kanade and Horn Shunck algorithms, to overcome the major problem when using thresholding method, which is only intensity or pixel magnitude is considered instead of relationships between the pixels. The results obtained could be observed in flow vector parameter and the segmentation colour based image for the time frame from 1 to 10 seconds. The visualization of both the parameters clarified the movement and changes of pixel intensity between two frames by the supportive colour segmentation, either in smooth or rough motion. Thus, this technique may contribute to others application such as biometrics, military system, and surveillance machine

Green synthesis of highly functionalized octahydropyrrolo[3,4-c]pyrrole derivatives using subcritical water, and their anti(myco)bacterial and antifungal activity

A series of novel 2-(thiazol-2-yl)-octahydropyrrolo[3,4-c]pyrroles was synthesized by reaction of octahydropyrrolo[3,4-c]pyrrole N-benzoylthiourea derivatives and α-haloketones in subcritical water at 130 °C in 75-91% yield. Both the thiourea intermediates and the end productswere synthesized in subcritical water, which proved a suitable green alternative to acetone by delivering the desired compounds in much shorter reaction times and practically the same yields. The antimicrobial activity of the compounds was determined against five bacterial strains and three fungal strains, and MIC values of 15.62-250 µg/mL were observed. Moreover, the compounds exhibited antimycobacterial activity against M. tuberculosis H37Rv with MIC values of 7.81-62.5 μg/mL

Triphasic Computed Tomography Enterography with Polyethylene Glycol to Detect Renal Cell Carcinoma Metastases to the Small Bowel

Enteroclysis was first used to diagnose small bowel obstruction in 1996. However, nasojejunal intubation required during enteroclysis causes discomfort to the patient. Triphasic computed tomography (CT) enterography, a noninvasive procedure that does not require intubation, was found to be an efficient method to diagnose small bowel lesions. We describe our experience of using triphasic CT enterography with polyethylene glycol (PEG) for diagnosing renal cell carcinoma (RCC) metastases to the small intestine. RCC can metastasize to many organs and can cause variable clinical presentations. We report the case of a 56-year-old man with RCC who had psoas muscle involvement and lung metastasis. The patient presented with melena and intermittent abdominal pain. Two conventional CT and small bowel series examinations had shown no obstructive lesion in the small intestine. However, triphasic CT enterography with PEG detected two enhanced masses suggestive of small bowel metastasis. The patient underwent laparotomy and segmental resection of the jejunum with primary anastomosis. Histologic examination was compatible with RCC. This is the first report where RCC metastasis to the small bowel was diagnosed using triphasic CT enterography. Our study emphasizes the importance of triphasic CT enterography in cases of obscure gastrointestinal bleeding, especially in patients suspected of having small bowel metastasis