Tsun-yee Yan - Academia.edu (original) (raw)

Papers by Tsun-yee Yan

Research paper thumbnail of <title>Earth beacon acquisition and tracking under various illumination conditions</title>

Proceedings of SPIE, Jun 20, 2001

Research paper thumbnail of <title>Use of cross-validation and Monte Carlo simulation for estimating the parameters of beaconless free-space optical pointing and tracking</title>

Proceedings of SPIE, Apr 30, 2002

To meet the micro-radian pointing accuracy required for deep space optical downlink telemetry, an... more To meet the micro-radian pointing accuracy required for deep space optical downlink telemetry, an algorithm has been proposed which uses the Earth as a beacon for locating the ground-based terminal. To enhance the resolution of the Earth beacon, a sequence of images is captured as the Earth image is moved across a CCD array in sub-pixel increments. Using this high resolution data, the algorithm then locates the ground-based terminal. The algorithm relies on two parameters for its solution; this paper develops techniques for estimating these parameters. To improve accuracy, a low pass filter is used in a pre-processing step to reduce the thermal noise introduced by the CCD array. The optimal cutoff frequency of the low pass filter is estimated using cross validation. The other parameter to be determined is a threshold used to extricate the Earth image from the background of the image. For this, a Monte Carlo simulation is used to determine the threshold that minimizes the mean squared error between the estimate and true locations of the ground-based terminal. Simulations indicate that the parameters can be determined very accurately using these methods. Results are presented.

Research paper thumbnail of An operational open-end file transfer protocol for mobile satellite communications

Research paper thumbnail of An adaptive detector and channel estimator for deep space optical communications

Research paper thumbnail of The Extended-Image Tracking Technique Based on the Maxium Likelihood Estimation

Research paper thumbnail of Strictly Bandlimited Modulations with Large Envelope Fluctuation (Nyquist Signaling)

John Wiley & Sons, Inc. eBooks, Jan 28, 2005

Research paper thumbnail of Definition Of The MSAT-X Network

Report describes state of development of Mobile Satellite Experiment (MSAT-X) network at end of 1... more Report describes state of development of Mobile Satellite Experiment (MSAT-X) network at end of 1989. Network includes mobile stations and base stations communicating by microwave radio relay via geostationary satellite. Provides three types of service: mobile telephone, mobile dispatch and digital data. Summarizes findings which serve as background for discussion of tentative specifications for design of network.

Research paper thumbnail of Preliminary Downlink Design and Performance Assessment for Advanced Radio Interferometry Between Space and Earth (ARISE)

Research paper thumbnail of Ultra High Bit Rate (Up to 1GBIT/S) Bandwidth Efficient FQPSK All-Digital Modulator/Demodulator Architectures and Nasa Implementations

International Telemetering Conference Proceedings, Oct 1, 2000

International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hote... more International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, CaliforniaThe paper presents ongoing efforts at NASA’s Goddard Space Flight Center and the Jet Propulsion Laboratory to develop ultra high bit rate bandwidth efficient FQPSK modulators and demodulators. The ability to transmit and receive ever-increasing amounts of extremely high rate data is an enduring challenge in the arena of near-earth space borne science missions. Reliable and efficient transmission of information at these data rates requires the use of power and bandwidth efficient modulations that exhibit low transmitter, receiver, and decoder complexity. Conventional high rate approaches for achieving spectral limiting typically employ sharp post amplifier filtering at the transmitter to limit the interference to the adjacent bands. However, using analog filtering alone can produce substantial intersymbol interference and other distortions that substantially affect the detection performance of the signal. In contrast, various theoretical classes of modulation waveforms can be tailored to provide varying degrees of bandwidth and power efficiency or robustness to non-linear transmitter distortions while incurring little or no performance losses. In order to realize many of these signal types, precise amplitude and phase control over the synthesis of these signals is required, typically necessitating the use of digital signal processing.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

Research paper thumbnail of A statistical model for evaluating GOPEX uplink performance

Telecommunications and Data Acquisition Progress Report, Nov 15, 1992

Research paper thumbnail of Power Spectrum of MSK-Type Modulations in the Presence of Data Imbalance

Research paper thumbnail of Enhanced Performance of FQPSK-B Receiver Based on Trellis-Coded Viterbi Demodulation

International Telemetering Conference Proceedings, Oct 23, 2000

Research paper thumbnail of Performance Evaluation and Interpretation of Unfiltered Feher-Patented Quadrature-Phase-Shift Keying (FQPSK)

Research paper thumbnail of Simpler Alternative to an Optimum FQPSK-B Viterbi Receiver

Research paper thumbnail of A Methodology Based on Reduced Complexity Algorithm for System Applications using Microprocessors

Control and dynamic systems, 1988

The paper considers a methodology on the analysis and design of a minimum mean-square error crite... more The paper considers a methodology on the analysis and design of a minimum mean-square error criterion linear system incorporating a tapped delay line (TDL) where all the full-precision multiplications in the TDL are constrained to be powers of two. A linear equalizer based on the dispersive and additive noise channel is presented. This microprocessor implementation with optimized power of two TDL coefficients achieves a system performance comparable to the optimum linear equalization with full-precision multiplications for an input data rate of 300 baud.

Research paper thumbnail of Quasi-Constant Envelope Modulations

John Wiley & Sons, Inc. eBooks, Jan 28, 2005

Research paper thumbnail of Constant Envelope Modulations

Research paper thumbnail of An optimized bandwidth efficient demand assigned protocol for integrated Mobile Satellite Services

This paper describes the design of a demand assigned protocol based on bandwidth efficiency for i... more This paper describes the design of a demand assigned protocol based on bandwidth efficiency for integrated services of a Mobile Satellite System (MSS). An MSS provides data (closed-ended) and voice (open-ended) communications services for a large number of mobile users dispersed over a wide geographical area. Each mobile requests its desired service through a designated set of channels to a network management center. Either pure or slotted ALOHA random access scheme can be used to make connection requests, while data and voice communications are demand assigned. All channels have equal bandwidth and can be adaptively used for reservation requests, data connections or voice connections to maximize the bandwidth utilization. In this paper, perfect communications channels are assumed. It has been shown that, for the case considered, using the slotted ALOHA scheme for making connection requests can save about 30 percent on the total number of channels over using the pure ALHOA scheme.

Research paper thumbnail of A Robust Spatial Acquisition Algorithm for Extended Source Using Subpixel Image Scanning

Research paper thumbnail of Performance analysis of the ALOHA protocol with replication in a fading channel for the Mobile Satellite Experiment

The analysis of the ALOHA random access protocol for communications channels with fading is prese... more The analysis of the ALOHA random access protocol for communications channels with fading is presented. The protocol is modified to send multiple contiguous copies of a message at each transmission attempt. Both pure and slotted ALOHA channels are considered. A general two state model is used for the channel error process to account for the channel fading memory. It is shown that greater throughput and smaller delay may be achieved using repetitions. The model is applied to the analysis of the delay-throughput performance in a fading mobile communications environment. Numerical results are given for NASA's Mobile Satellite Experiment.

Research paper thumbnail of <title>Earth beacon acquisition and tracking under various illumination conditions</title>

Proceedings of SPIE, Jun 20, 2001

Research paper thumbnail of <title>Use of cross-validation and Monte Carlo simulation for estimating the parameters of beaconless free-space optical pointing and tracking</title>

Proceedings of SPIE, Apr 30, 2002

To meet the micro-radian pointing accuracy required for deep space optical downlink telemetry, an... more To meet the micro-radian pointing accuracy required for deep space optical downlink telemetry, an algorithm has been proposed which uses the Earth as a beacon for locating the ground-based terminal. To enhance the resolution of the Earth beacon, a sequence of images is captured as the Earth image is moved across a CCD array in sub-pixel increments. Using this high resolution data, the algorithm then locates the ground-based terminal. The algorithm relies on two parameters for its solution; this paper develops techniques for estimating these parameters. To improve accuracy, a low pass filter is used in a pre-processing step to reduce the thermal noise introduced by the CCD array. The optimal cutoff frequency of the low pass filter is estimated using cross validation. The other parameter to be determined is a threshold used to extricate the Earth image from the background of the image. For this, a Monte Carlo simulation is used to determine the threshold that minimizes the mean squared error between the estimate and true locations of the ground-based terminal. Simulations indicate that the parameters can be determined very accurately using these methods. Results are presented.

Research paper thumbnail of An operational open-end file transfer protocol for mobile satellite communications

Research paper thumbnail of An adaptive detector and channel estimator for deep space optical communications

Research paper thumbnail of The Extended-Image Tracking Technique Based on the Maxium Likelihood Estimation

Research paper thumbnail of Strictly Bandlimited Modulations with Large Envelope Fluctuation (Nyquist Signaling)

John Wiley & Sons, Inc. eBooks, Jan 28, 2005

Research paper thumbnail of Definition Of The MSAT-X Network

Report describes state of development of Mobile Satellite Experiment (MSAT-X) network at end of 1... more Report describes state of development of Mobile Satellite Experiment (MSAT-X) network at end of 1989. Network includes mobile stations and base stations communicating by microwave radio relay via geostationary satellite. Provides three types of service: mobile telephone, mobile dispatch and digital data. Summarizes findings which serve as background for discussion of tentative specifications for design of network.

Research paper thumbnail of Preliminary Downlink Design and Performance Assessment for Advanced Radio Interferometry Between Space and Earth (ARISE)

Research paper thumbnail of Ultra High Bit Rate (Up to 1GBIT/S) Bandwidth Efficient FQPSK All-Digital Modulator/Demodulator Architectures and Nasa Implementations

International Telemetering Conference Proceedings, Oct 1, 2000

International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hote... more International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, CaliforniaThe paper presents ongoing efforts at NASA’s Goddard Space Flight Center and the Jet Propulsion Laboratory to develop ultra high bit rate bandwidth efficient FQPSK modulators and demodulators. The ability to transmit and receive ever-increasing amounts of extremely high rate data is an enduring challenge in the arena of near-earth space borne science missions. Reliable and efficient transmission of information at these data rates requires the use of power and bandwidth efficient modulations that exhibit low transmitter, receiver, and decoder complexity. Conventional high rate approaches for achieving spectral limiting typically employ sharp post amplifier filtering at the transmitter to limit the interference to the adjacent bands. However, using analog filtering alone can produce substantial intersymbol interference and other distortions that substantially affect the detection performance of the signal. In contrast, various theoretical classes of modulation waveforms can be tailored to provide varying degrees of bandwidth and power efficiency or robustness to non-linear transmitter distortions while incurring little or no performance losses. In order to realize many of these signal types, precise amplitude and phase control over the synthesis of these signals is required, typically necessitating the use of digital signal processing.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

Research paper thumbnail of A statistical model for evaluating GOPEX uplink performance

Telecommunications and Data Acquisition Progress Report, Nov 15, 1992

Research paper thumbnail of Power Spectrum of MSK-Type Modulations in the Presence of Data Imbalance

Research paper thumbnail of Enhanced Performance of FQPSK-B Receiver Based on Trellis-Coded Viterbi Demodulation

International Telemetering Conference Proceedings, Oct 23, 2000

Research paper thumbnail of Performance Evaluation and Interpretation of Unfiltered Feher-Patented Quadrature-Phase-Shift Keying (FQPSK)

Research paper thumbnail of Simpler Alternative to an Optimum FQPSK-B Viterbi Receiver

Research paper thumbnail of A Methodology Based on Reduced Complexity Algorithm for System Applications using Microprocessors

Control and dynamic systems, 1988

The paper considers a methodology on the analysis and design of a minimum mean-square error crite... more The paper considers a methodology on the analysis and design of a minimum mean-square error criterion linear system incorporating a tapped delay line (TDL) where all the full-precision multiplications in the TDL are constrained to be powers of two. A linear equalizer based on the dispersive and additive noise channel is presented. This microprocessor implementation with optimized power of two TDL coefficients achieves a system performance comparable to the optimum linear equalization with full-precision multiplications for an input data rate of 300 baud.

Research paper thumbnail of Quasi-Constant Envelope Modulations

John Wiley & Sons, Inc. eBooks, Jan 28, 2005

Research paper thumbnail of Constant Envelope Modulations

Research paper thumbnail of An optimized bandwidth efficient demand assigned protocol for integrated Mobile Satellite Services

This paper describes the design of a demand assigned protocol based on bandwidth efficiency for i... more This paper describes the design of a demand assigned protocol based on bandwidth efficiency for integrated services of a Mobile Satellite System (MSS). An MSS provides data (closed-ended) and voice (open-ended) communications services for a large number of mobile users dispersed over a wide geographical area. Each mobile requests its desired service through a designated set of channels to a network management center. Either pure or slotted ALOHA random access scheme can be used to make connection requests, while data and voice communications are demand assigned. All channels have equal bandwidth and can be adaptively used for reservation requests, data connections or voice connections to maximize the bandwidth utilization. In this paper, perfect communications channels are assumed. It has been shown that, for the case considered, using the slotted ALOHA scheme for making connection requests can save about 30 percent on the total number of channels over using the pure ALHOA scheme.

Research paper thumbnail of A Robust Spatial Acquisition Algorithm for Extended Source Using Subpixel Image Scanning

Research paper thumbnail of Performance analysis of the ALOHA protocol with replication in a fading channel for the Mobile Satellite Experiment

The analysis of the ALOHA random access protocol for communications channels with fading is prese... more The analysis of the ALOHA random access protocol for communications channels with fading is presented. The protocol is modified to send multiple contiguous copies of a message at each transmission attempt. Both pure and slotted ALOHA channels are considered. A general two state model is used for the channel error process to account for the channel fading memory. It is shown that greater throughput and smaller delay may be achieved using repetitions. The model is applied to the analysis of the delay-throughput performance in a fading mobile communications environment. Numerical results are given for NASA's Mobile Satellite Experiment.