Jean-Paul M. G. Linnartz is a Research Fellow with Signify (Philips Lighting) and a full professor at Eindhoven University of Technology. He and his research team work on optical wireless communication systems and on personalized human centric lighting. He initiated research on “Coded Light”, to allow the embedding of identifiers in light sources, which is now being used for indoor positioning in many office and retail facilities and he worked with the Trulifi team at Signify. As a Senior Director with Philips Research, Eindhoven, he headed security, connectivity and IC design research groups. His inventions led to more than 75 granted patents and have been a basis for successful ventures. His work has been cited over 11,000 times (GS) and he is Fellow of the IEEE for leadership in security with noisy data. His concept for uniquely securing processors is now used in over half a Billion IoT devices. During 1992-1995, he was an Assistant Professor with the University of California at Berkeley. He most cited work is the introduction of Multi-Carrier CDMA in 1993. In 1994, he was Associate Professor with TU Delft.
Thermal transient testing is widely used for LED characterization, derivation of compact models, ... more Thermal transient testing is widely used for LED characterization, derivation of compact models, and calibration of 3D finite element models. The traditional analysis of transient thermal measurements yields a thermal model for a single heat source. However, it appears that secondary heat sources are typically present in LED packages and significantly limit the model’s precision. In this paper, we reveal inaccuracies of thermal transient measurements interpretation associated with the secondary heat sources related to the light trapped in an optical encapsulant and phosphor light conversion losses. We show that both have a significant impact on the transient response for mid-power LED packages. We present a novel methodology of a derivation and calibration of thermal models for LEDs with multiple heat sources. It can be applied not only to monochromatic LEDs but particularly also to LEDs with phosphor light conversion. The methodology enables a separate characterization of the prima...
Infrared (IR) wireless systems offer an easy-toassemble and low-cost alternative to radio communi... more Infrared (IR) wireless systems offer an easy-toassemble and low-cost alternative to radio communications. In this paper, we focus on the advantages of using IR communications in large scale networks with hundreds or thousands of nodes, where the propagation of messages is hindered by the many simultaneous transmissions. Initially, we examine theoretically the propagation of IR power between nodes in indoor environments where no line-of-sight links exist and IR radiation can only reach the receiver through reflections on the floor and the ceiling. In such network configurations, the rapid attenuation of the electrical power of the received IR signals, which decreases as 1=d8 H with horizontal distance dH, can be advantageous for mitigating the accumulation of interference. Then, we present experimental results that verify our theoretical models and demonstrate a prototype system of IR communication between two nodes in such an indoor setting. Our results hold great potential for the mitigation of interference in large-scale indoor cellular networks, since every node is only able to exchange messages with its close-by neighbors.
This paper bounds the performance of a uniformpower and a waterfilling algorithm for low-pass cha... more This paper bounds the performance of a uniformpower and a waterfilling algorithm for low-pass channels. It is shown that a visible light communication channel with double hetero-structure LEDs in their linear regime can be approximated by a first order low-pass channel. Closed form expressions are derived to relate the maximum achievable data rate (capacity) and the corresponding optimum bandwidth usage to the input total (modulation) power.
Frequency modulated continuous wave (FMCW) radars have been widely used for measuring target rang... more Frequency modulated continuous wave (FMCW) radars have been widely used for measuring target range and speed. In this paper, we present a mathematical model that quantifies the system-level performance of FMCW radar systems. In FMCW radar, the target range is measured through measuring the beat frequency between the transmitted and received signal, usually by using Fast Fourier Transform (FFT). One drawback of this approach is that when the beat frequency of a target is not on the FFT grid, both the detection probability and the false alarm rate (FAR) performances are degraded. In this paper, we propose a new detector, using frequency shifts, that improves the detection probability for off the grid targets at a cost of a slight increase in FAR.
Smart buildings with connected lighting and sensors are likely to become one of the first large-s... more Smart buildings with connected lighting and sensors are likely to become one of the first large-scale applications of the Internet of Things (IoT). However, as the number of interconnected IoT devices is expected to rise exponentially, the amount of collected data will be enormous but highly redundant. Devices will be required to pre-process data locally or at least in their vicinity. Thus, local data fusion, subject to constraint communications will become necessary. In that sense, distributed architectures will become increasingly unavoidable. Anticipating this trend, this paper addresses the problem of presence detection in a building as a distributed sensing of a hidden Markov model (DS-HMM) with limitations on the communication. The key idea in our work is the use of a posteriori probabilities or likelihood ratios (LR) as an appropriate “interface” between heterogeneous sensors with different error profiles. We propose an efficient transmission policy, jointly with a fusion alg...
In modern society, the average person spends more than 90% of their time indoors. However, despit... more In modern society, the average person spends more than 90% of their time indoors. However, despite the growing scientific understanding of the impact of light on biological mechanisms, the existing light in the built environment is designed predominantly to meet visual performance requirements only. Lighting can also be exploited as a means to improve occupant health and well-being through the circadian functions that regulate sleep, mood, and alertness. The benefits of well-lit spaces map across other regularly occupied building types, such as residences and schools, as well as patient rooms in healthcare and assisted-living facilities. Presently, Human Centric Lighting is being offered based on generic insights on population average experiences. In this paper, we suggest a personalized bio-adaptive office lighting system, controlled to emit a lighting recipe tailored to the individual employee. We introduce a new mathematical optimization for lighting schedules that align the 24-h...
Thermal transient testing is widely used for LED characterization, derivation of compact models, ... more Thermal transient testing is widely used for LED characterization, derivation of compact models, and calibration of 3D finite element models. The traditional analysis of transient thermal measurements yields a thermal model for a single heat source. However, it appears that secondary heat sources are typically present in LED packages and significantly limit the model’s precision. In this paper, we reveal inaccuracies of thermal transient measurements interpretation associated with the secondary heat sources related to the light trapped in an optical encapsulant and phosphor light conversion losses. We show that both have a significant impact on the transient response for mid-power LED packages. We present a novel methodology of a derivation and calibration of thermal models for LEDs with multiple heat sources. It can be applied not only to monochromatic LEDs but particularly also to LEDs with phosphor light conversion. The methodology enables a separate characterization of the prima...
Infrared (IR) wireless systems offer an easy-toassemble and low-cost alternative to radio communi... more Infrared (IR) wireless systems offer an easy-toassemble and low-cost alternative to radio communications. In this paper, we focus on the advantages of using IR communications in large scale networks with hundreds or thousands of nodes, where the propagation of messages is hindered by the many simultaneous transmissions. Initially, we examine theoretically the propagation of IR power between nodes in indoor environments where no line-of-sight links exist and IR radiation can only reach the receiver through reflections on the floor and the ceiling. In such network configurations, the rapid attenuation of the electrical power of the received IR signals, which decreases as 1=d8 H with horizontal distance dH, can be advantageous for mitigating the accumulation of interference. Then, we present experimental results that verify our theoretical models and demonstrate a prototype system of IR communication between two nodes in such an indoor setting. Our results hold great potential for the mitigation of interference in large-scale indoor cellular networks, since every node is only able to exchange messages with its close-by neighbors.
This paper bounds the performance of a uniformpower and a waterfilling algorithm for low-pass cha... more This paper bounds the performance of a uniformpower and a waterfilling algorithm for low-pass channels. It is shown that a visible light communication channel with double hetero-structure LEDs in their linear regime can be approximated by a first order low-pass channel. Closed form expressions are derived to relate the maximum achievable data rate (capacity) and the corresponding optimum bandwidth usage to the input total (modulation) power.
Frequency modulated continuous wave (FMCW) radars have been widely used for measuring target rang... more Frequency modulated continuous wave (FMCW) radars have been widely used for measuring target range and speed. In this paper, we present a mathematical model that quantifies the system-level performance of FMCW radar systems. In FMCW radar, the target range is measured through measuring the beat frequency between the transmitted and received signal, usually by using Fast Fourier Transform (FFT). One drawback of this approach is that when the beat frequency of a target is not on the FFT grid, both the detection probability and the false alarm rate (FAR) performances are degraded. In this paper, we propose a new detector, using frequency shifts, that improves the detection probability for off the grid targets at a cost of a slight increase in FAR.
Smart buildings with connected lighting and sensors are likely to become one of the first large-s... more Smart buildings with connected lighting and sensors are likely to become one of the first large-scale applications of the Internet of Things (IoT). However, as the number of interconnected IoT devices is expected to rise exponentially, the amount of collected data will be enormous but highly redundant. Devices will be required to pre-process data locally or at least in their vicinity. Thus, local data fusion, subject to constraint communications will become necessary. In that sense, distributed architectures will become increasingly unavoidable. Anticipating this trend, this paper addresses the problem of presence detection in a building as a distributed sensing of a hidden Markov model (DS-HMM) with limitations on the communication. The key idea in our work is the use of a posteriori probabilities or likelihood ratios (LR) as an appropriate “interface” between heterogeneous sensors with different error profiles. We propose an efficient transmission policy, jointly with a fusion alg...
In modern society, the average person spends more than 90% of their time indoors. However, despit... more In modern society, the average person spends more than 90% of their time indoors. However, despite the growing scientific understanding of the impact of light on biological mechanisms, the existing light in the built environment is designed predominantly to meet visual performance requirements only. Lighting can also be exploited as a means to improve occupant health and well-being through the circadian functions that regulate sleep, mood, and alertness. The benefits of well-lit spaces map across other regularly occupied building types, such as residences and schools, as well as patient rooms in healthcare and assisted-living facilities. Presently, Human Centric Lighting is being offered based on generic insights on population average experiences. In this paper, we suggest a personalized bio-adaptive office lighting system, controlled to emit a lighting recipe tailored to the individual employee. We introduce a new mathematical optimization for lighting schedules that align the 24-h...
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Papers by Jean-Paul Linnartz