Search results for "0508 media and communications"
showing 10 items of 683 documents
Non-cooperative Aerial Base Station Placement via Stochastic Optimization
2019
Autonomous unmanned aerial vehicles (UAVs) with on-board base station equipment can potentially provide connectivity in areas where the terrestrial infrastructure is overloaded, damaged, or absent. Use cases comprise emergency response, wildfire suppression, surveillance, and cellular communications in crowded events to name a few. A central problem to enable this technology is to place such aerial base stations (AirBSs) in locations that approximately optimize the relevant communication metrics. To alleviate the limitations of existing algorithms, which require intensive and reliable communications among AirBSs or between the AirBSs and a central controller, this paper leverages stochastic…
Secrecy analysis and learning-based optimization of cooperative NOMA SWIPT systems
2019
Non-orthogonal multiple access (NOMA) is considered to be one of the best candidates for future networks due to its ability to serve multiple users using the same resource block. Although early studies have focused on transmission reliability and energy efficiency, recent works are considering cooperation among the nodes. The cooperative NOMA techniques allow the user with a better channel (near user) to act as a relay between the source and the user experiencing poor channel (far user). This paper considers the link security aspect of energy harvesting cooperative NOMA users. In particular, the near user applies the decode-and-forward (DF) protocol for relaying the message of the source no…
Design of SCMA Codebooks using Differential Evolution
2020
Non-orthogonal multiple access (NOMA) is a promising technology which meets the demands of massive connectivity in future wireless networks. Sparse code multiple access (SCMA) is a popular code-domain NOMA technique. The effectiveness of SCMA comes from: (1) the multi-dimensional sparse codebooks offering high shaping gain and (2) sophisticated multi-user detection based on message passing algorithm (MPA). The codebooks of the users play the main role in determining the performance of SCMA system. This paper presents a framework to design the codebooks by taking into account the entire system including the SCMA encoder and the MPA-based detector. The symbol-error rate (SER) is considered as…
Network-Assisted Resource Allocation with Quality and Conflict Constraints for V2V Communications
2018
The 3rd Generation Partnership Project (3GPP) has recently established in Rel. 14 a network-assisted resource allocation scheme for vehicular broadcast communications. Such novel paradigm is known as vehicle--to--vehicle (V2V) \textit{mode-3} and consists in eNodeBs engaging only in the distribution of sidelink subchannels among vehicles in coverage. Thereupon, without further intervention of the former, vehicles will broadcast their respective signals directly to their counterparts. Because the allotment of subchannels takes place intermittently to reduce signaling, it must primarily be conflict-free in order not to jeopardize the reception of signals. We have identified four pivotal types…
Data-Driven Spectrum Cartography via Deep Completion Autoencoders
2019
Spectrum maps, which provide RF spectrum metrics such as power spectral density for every location in a geographic area, find numerous applications in wireless communications such as interference control, spectrum management, resource allocation, and network planning to name a few. Spectrum cartography techniques construct these maps from a collection of measurements collected by spatially distributed sensors. Due to the nature of the propagation of electromagnetic waves, spectrum maps are complicated functions of the spatial coordinates. For this reason, model-free approaches have been preferred. However, all existing schemes rely on some interpolation algorithm unable to learn from data. …
Aerial Spectrum Surveying: Radio Map Estimation with Autonomous UAVs
2020
Radio maps are emerging as a popular means to endow next-generation wireless communications with situational awareness. In particular, radio maps are expected to play a central role in unmanned aerial vehicle (UAV) communications since they can be used to determine interference or channel gain at a spatial location where a UAV has not been before. Existing methods for radio map estimation utilize measurements collected by sensors whose locations cannot be controlled. In contrast, this paper proposes a scheme in which a UAV collects measurements along a trajectory. This trajectory is designed to obtain accurate estimates of the target radio map in a short time operation. The route planning a…
Just One More Episode: Predictors of Procrastination with Television and Implications for Sleep Quality
2019
© 2019, © 2019 Mass Communication & Society Division of the Association for Education in Journalism and Mass Communication. Sleep experts have raised concern over the effects of electronic media use on sleep. To date, few studies have looked beyond the effects of duration and frequency of media exposure or examined the underlying mechanisms of this association. As procrastinatory media use has been related to lower well-being, we used data from two survey studies (N1 = 821, N2 = 584) to investigate (a) predictors of procrastinatory TV viewing and (b) the link between procrastinatory TV viewing and sleep quality. Findings from both studies indicate that those with a stronger viewing habit, h…
Smartphone Usage Among Millennial in Finland and Implications for Marketing Segmentation Strategies: Lessons for Nigeria
2018
The study examines smart phone usage by millennials based on different criteria of operating system, Wi-Fi, text messaging, internet surfing and social media. The study used quantitative methodology and data were gathered with online questionnaires with 391 young smartphone users in Finland. The Millennial were clustered into five levels. The results reveal the prominent status of profiling in a developed market and how marketers in emerging markets can apply segmentation and targeting strategies using instant messaging, text messages, email, mobile app, gamification and social media based on the profile of each segment. Nigerian policy makers should adopt a framework to make smartphone aff…
Habitual initiation of media use and a response-frequency measure for its examination
2014
When measuring media habits, most scholars rely on retrospective self-reports about behavioral frequency, context stability, or automaticity of the performance. This article develops a new implicit measurement for media research to complement existing approaches, which focuses on measuring the initiation of general, goal-related habits. In the response-frequency measure of media habit (RFMMH), participants are presented with several media use goals and are asked to choose quickly and without deliberation which media device (television set, radio set, newspaper, computer, mobile device) they would use. The more often a media device is chosen, the stronger the mental script to choose this dev…
Procrastination out of Habit? The Role of Impulsive Versus Reflective Media Selection in Procrastinatory Media Use
2018
The pervasive access to media options seriously challenges users’ self-regulatory abilities. One example of deficient self-regulation in the context of media use is procrastination—impulsively ‘giving in’ to available media options despite goal conflicts with more important tasks. This study investigaes procrastinatory media use across 3 types of media (TV, computer, smartphone) from a dual-systems perspective, taking both person-level and situation-level predictors into account. Results from a 14-day long diary study (N = 347) suggest that procrastinatory media use is driven by automatic media selection, which is facilitated by strong media habits (person level) and low motivation for beha…