Scheduling heuristic for reduced complexity of coordinated beamforming in large multi-carrier heterogeneous wireless networks

The research and development of wireless communication systems is often based on relatively simple models of the network topology, the radio channel and the radio propagation. This is considered to be mostly appropriate, as only under these conditions the complex technical problems in this field can be fully solved to their theoretical boundaries. However, it can also be the case that algorithms or concepts created under simplified assumptions perform in a significantly different way, when they are applied in more realistic scenarios. This Thesis presents research work which can be seen as a step towards extending the existing research on Coordinated Beamforming to a complex network scenario, i.e. to a large-scale heterogeneous multi-carrier network. For this purpose, a complex simulation framework has been developed. This is used to analyse the significant implications the conditions in a complex network can have on the achievable performance gains. In more detail, the out of cluster interference and the number of mobile stations are identified as factors which heavily influence the performance. This knowledge is then used to design a novel scheduling heuristic, designed to be able to adapt to the particular network scenarios and to estimate the extent of the achievable performance gains. Our simulation results show that the new heuristic achieves significant performance gains for a low number of mobile stations (by applying zero forcing precoding) as well as for a high number of mobile stations (by a coordinated resource assignment that intelligently pairs mobile stations when applying maximum ratio transmission). The Thesis also demonstrates that the effect of the out of cluster interference can cause the reduction of the achievable gains. Due to the knowledge of performance limiting factors, the scheduling heuristic is in addition able to realize a trade-off between complexity and performance by excluding transmission parameters from the scheduling process which are not expected to be beneficial

Scheduling Algorithm for Coordinated Beamforming in Heterogeneous Macro/Pico LTE-Advanced Networks

Pico base stations are an important instrument to increase the capacity of mobile radio networks. Due to the limited spectrum availability it will be necessary to operate macro and pico base stations on the same frequency bands. In this case the transmit power imbalance between different base station types creates new interference situations. Coordinated beamforming is one method of base station cooperation that can be applied to mitigate interference in this scenario. The work presented here describes a scheduler for coordinated beamforming in an LTE-Advanced system which relies on sharing only the feedback information from the mobile stations between the base stations. System level simulation results show that this approach can decrease the interference experienced by the mobile stations attached to the pico base stations

Complexity of coordinated beamforming and scheduling for OFDMA based heterogeneous networks

Coordination is foreseen to be an important component of future mobile radio networks. It is especially relevant in heterogeneous networks, where high power base stations produce strong interference to an underlying layer of low power base stations. This work investigates in detail the achievable performance gains for one coordination technique—coordinated beamforming. It reveals the main factors that influence the throughput of the mobile stations. These findings are combined with an analysis of the computational complexity. As a result, a heuristic algorithm is presented that achieves results close to an exhaustive search with significantly less calculations. Detailed simulation analysis is presented on a realistic network layout

Effects of Treatment Setting on Outcomes of Flexibly-Dosed Intensive Cognitive Behavioral Therapy for Pediatric OCD : A Randomized Controlled Pilot Trial

Funding Information: The study authors would like to acknowledge the planning support of Drs. Eric Storch and Katherine Martinez, the recruitment and administrative support of the Provincial OCD Program Team at BC Children's Hospital, and the participation of all families. Funding. This study was supported by postdoctoral awards to RS from the Michael Smith Foundation for Health Research (#17821) and the BC Children's Hospital Research Institute. Both awards provided salary support for RS as well as research funds to support study implementation (e.g., staff salaries, participant reimbursement, etc.). A private donation to the Provincial OCD Program via the BC Children's Hospital Foundation also supported some research costs. Funding Information: This study was supported by postdoctoral awards to RS from the Michael Smith Foundation for Health Research (#17821) and the BC Children’s Hospital Research Institute. Both awards provided salary support for RS as well as research funds to support study implementation (e.g., staff salaries, participant reimbursement, etc.). A private donation to the Provincial OCD Program via the BC Children’s Hospital Foundation also supported some research costs. Publisher Copyright: © Copyright © 2021 Selles, Naqqash, Best, Franco-Yamin, Qiu, Ferreira, Deng, Hannesdottir, Oberth, Belschner, Negreiros, Farrell and Stewart.Introduction: Optimizing individual outcomes of cognitive-behavioral therapy (CBT) remains a priority. Methods: Youth were randomized to receive intensive CBT at a hospital clinic (n = 14) or within their home (n = 12). Youth completed 3 × 3 h sessions (Phase I) and up to four additional 3-h sessions as desired/needed (Phase II). An independent evaluator assessed youth after Phase I, Phase II (when applicable), and at 1- and 6-months post-treatment. A range of OCD-related (e.g., severity, impairment) and secondary (e.g., quality of life, comorbid symptoms) outcomes were assessed. Results: Families' satisfaction with the treatment program was high. Of study completers (n = 22), five youth (23%) utilized no Phase II sessions and 9 (41%) utilized all four (Median Phase II sessions: 2.5). Large improvements in OCD-related outcomes and small-to-moderate benefits across secondary domains were observed. Statistically-significant differences in primary outcomes were not observed between settings; however, minor benefits for home-based treatment were observed (e.g., maintenance of gains, youth comfort with treatment). Discussion: Intensive CBT is an efficacious treatment for pediatric OCD. Families opted for differing doses based on their needs. Home-based treatment, while not substantially superior to hospital care, may offer some value, particularly when desired/relevant. Clinical Trial Registration: www.ClinicalTrials.gov; https://clinicaltrials.gov/ct2/show/NCT03672565, identifier: NCT03672565.Peer reviewe

Hierarchies of Representation: The Re-distributive Effects of Gender and Youth Quotas

This article investigates how paired electoral quotas re-distribute parliamentary seats between majority and minority groups. Focusing on gender and youth quotas, we use the concept of Hierarchies of Representation to analyse the political inclusion of intersectional groups. We use a dataset of 146 countries and two case studies to explore quotas’ effects on HoR under different quota constellations. We find that paired quotas tend to re-distribute power among women and youth rather than challenge middle-aged men’s parliamentary dominance

Increasing System Safety for by-wire Applications in Vehicles by using a Time Triggered Architecture

Abstract. By-wire systems have been established for several years in the area of aircraft construction and there are now approaches to utilize this technology in vehicles. The required electronic systems must evidently be available and safe. In the same time the requirements of mass production have to be reached (long life time, long maintainability intervals, low costs, fulfillment of standards). This paper addresses a new automotive architecture approach-based on a time triggered architecture- and a framework for the application design of future by-wire systems in vehicles