Papers by Thomas D C Little
Guest Editorial: Introduction to Special Issue on NOSSDAV 1995
Mms, 1997
Service Aggregation Through a Novel Rate Adaptation Technique Using a Single Storage Format
Nossdav, 1997
The virtual video browser in Mosaic (demonstration)
Proceedings of the Second Acm International Conference on Multimedia, Oct 15, 1994
ABSTRACT
Visible light communications: demand factors, benefits and opportunities [Guest Editorial]
Ieee Wireless Communications, Apr 1, 2015
Adaptation of OFDM under visible light communications and illumination constraints
2014 48th Asilomar Conference on Signals Systems and Computers, Nov 1, 2014
Information personalization is increasingly viewed as an essential component of any front-end to ... more Information personalization is increasingly viewed as an essential component of any front-end to a large information space. Personalization can achieve both customization of the presentation of information as well as tailoring of the content itself.
Network and Operating System Support for Digital Audio and Video, 5th International Workshop, NOSSDAV '95, Durham, New Hampshire, USA, April 19-21, 1995, Proceedings
Nossdav, 1995
Polar-Based OFDM and SC-FDE Links Toward Energy-Efficient Gbps Transmission Under IM-DD Optical System Constraints [Invited]
Journal of Optical Communications and Networking, 2014
Techniques For Automatic Digital Video Composition
... education so enjoyable. I owe a lot to my colleagues at MCL, particularly Anand Krishnamurthy... more ... education so enjoyable. I owe a lot to my colleagues at MCL, particularly Anand Krishnamurthy, Dinesha Venkatesh, Rajesh Krishnan, William Klippgen, Prithwish Basu, Ashok Narayanan, Karthikeyan Srinivasan, Leonardo Ligresti, Leslie Kuczynski, Marco Car-...
An instrument scheduler design for energy neutral coastal monitoring systems deployment
Proceedings of the 2nd International Workshop, Nov 6, 2014
Sensory Lighting System and Method for Characterizing an Illumination Space
Sample indexed spatial orthogonal frequency division multiplexing
Chinese Optics Letters, Aug 8, 2014
Journal of Optical Communications and Networking, 2015
Visible light communication (VLC) has wide unlicensed bandwidth, enables communication in radio f... more Visible light communication (VLC) has wide unlicensed bandwidth, enables communication in radio frequency (RF) sensitive environments, realizes energy-efficient data transmission, and has the potential to boost the capacity of wireless access networks through spatial reuse. On the other hand, WiFi provides more coverage than VLC and does not suffer from the likelihood of blockage due to the light of sight (LOS) requirement of VLC. In order to take the advantages of both WiFi and VLC, we propose and implement two heterogeneous systems with Internet access. One is the hybrid WiFi-VLC system, utilizing unidirectional VLC channel as downlink and reserving the WiFi back-channel as uplink. The asymmetric solution resolves the optical uplink challenges and benefits from the full-duplex communication based on VLC. To further enhance the robustness and increase throughput, the other system is presented, in which we aggregate WiFi and VLC in parallel by leveraging the bonding technique in Linux operating system. Online experiment results reveal that the hybrid system outperforms the conventional WiFi for the crowded environments in terms of throughput and web page loading time; and also demonstrate the further improved performance of the aggregated system when considering the blocking duration and the distance between access point and user device.
Visible light communication (VLC) has wide unlicensed bandwidth, enables communication in radio f... more Visible light communication (VLC) has wide unlicensed bandwidth, enables communication in radio frequency (RF) sensitive environments, realizes energy-efficient data transmission, and has the potential to boost the capacity of wireless access networks through spatial reuse. On the other hand, WiFi provides more coverage than VLC and does not suffer from the likelihood of blockage due to the light of sight (LOS) requirement of VLC. In order to take the advantages of both WiFi and VLC, we propose and implement two heterogeneous systems with Internet access. One is the hybrid WiFi-VLC system, utilizing unidirectional VLC channel as downlink and reserving the WiFi back-channel as uplink. The asymmetric solution resolves the optical uplink challenges and benefits from the full-duplex communication based on VLC. To further enhance the robustness and increase throughput, the other system is presented, in which we aggregate WiFi and VLC in parallel by leveraging the bonding technique in Lin...
On the Performance Gains of Cooperative Transmission Concepts in Intensity Modulated Direct Detection Visible Light Communication Networks
2010 6th International Conference on Wireless and Mobile Communications, 2010
Visible light communication networks are currently constrained in range by the divergent source c... more Visible light communication networks are currently constrained in range by the divergent source characteristics of the light emmiting diode (LED) and in achievable rate by the modulation bandwidth of the LED transmitter; however, as device advancements improve the limitation on rate becomes inter-symbol interference (ISI). The key contributor to ISI is the non-uniform time of arrival (TOA) of all light
Adaptation of OFDM under visible light communications and illumination constraints
2014 48th Asilomar Conference on Signals, Systems and Computers, 2014
P-OFDM: Spectrally Efficient Unipolar OFDM
Optical Fiber Communication Conference, 2014
ABSTRACT A novel OFDM signal format, polar-OFDM (P-OFDM), is proposed. P-OFDM offers twice as muc... more ABSTRACT A novel OFDM signal format, polar-OFDM (P-OFDM), is proposed. P-OFDM offers twice as much spectral efficiency as state-of-the-art real-value unipolar OFDM formats. Inherently, the high PAPR is reduced and the numerical evaluation of the BER performance under dynamic-range constraint of optical sources demonstrates superior results.
Optics express, Jan 7, 2013
Visible light communications (VLC) technology permits the exploitation of light-emitting diode (L... more Visible light communications (VLC) technology permits the exploitation of light-emitting diode (LED) luminaries for simultaneous illumination and broadband wireless communication. Optical orthogonal frequency-division multiplexing (O-OFDM) is a promising modulation technique for VLC systems, in which the real-valued O-OFDM baseband signal is used to modulate the instantaneous power of the optical carrier to achieve gigabit data rates. However, a major design challenge that limits the commercialization of VLC is how to incorporate the industry-preferred pulse-width modulation (PWM) light dimming technique while maintaining a broadband and reliable communication link. In this work, a novel signal format, reverse polarity O-OFDM (RPO-OFDM), is proposed to combine the fast O-OFDM communication signal with the relatively slow PWM dimming signal, where both signals contribute to the effective LED brightness. The advantages of using RPO-OFDM include, (1) the data rate is not limited by the...
Performance of optical spatial modulation and spatial multiplexing with imaging receiver
2014 IEEE Wireless Communications and Networking Conference (WCNC), 2014
ABSTRACT Spatial modulation (SM) and spatial multiplexing (SMP) are two multiple-input multiple-o... more ABSTRACT Spatial modulation (SM) and spatial multiplexing (SMP) are two multiple-input multiple-output (MIMO) techniques for transmitting data over an indoor optical wireless channel. Receivers for SM and SMP can be of the non-imaging type, in which case the channel matrix coefficients can be highly correlated, or of the imaging type, which can reduce the degree of correlation and improve overall system performance. In this work, we propose a new framework to analyze the performance of imaging MIMO systems. This framework is applied to characterize the performance of SM and SMP under both imaging and non-imaging receivers. Results of our analysis indicate that imaging receivers can provide significant signal-to-noise ratio (SNR) improvements up to 45dB under SM and SMP as compared to the use of non-imaging receivers. Finally, the application of the proposed analysis framework indicates specific design principles to optimize imaging receiver parameters.
2012 Fourth International Conference on Communication Systems and Networks (COMSNETS 2012), 2012
The ubiquity of smartphones and their capability to support complex data collection, processing a... more The ubiquity of smartphones and their capability to support complex data collection, processing and communications applications is leading to a revolution in personal healthcare. Always 'on' and carried, and seamlessly connected to multiple network technologies such as WiFi, Bluetooth, and cellular carrier, these devices can be adopted as hub for aggregating data sourced from custom body-worn sensors. To be effective, however, these devices must balance the diverse design specifications for intermittent smart phone use with the real-time characteristic of health monitoring telemetry. In this paper we focus on the development of sensing devices supporting in-home and community-based health monitoring. We describe the design of a low powered, compact, wireless, and customizable platform for wearable activity monitoring. Of particular importance in this design is the ability to achieve sufficient spatial and temporal sampling resolution for the activity detection mission while meeting battery size and longevity constraints. The sensor design is paired with data aggregation using a WPAN and smartphone to support a body worn network capable of interaction with local telemetry to provide continuous functional activity monitoring, real time activity classification, and notification. Predicted and measured performance data indicate satisfaction of the mission with huge potential gains after optimization of sampling strategies.
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Papers by Thomas D C Little