Engineering topics
Lay, N.
Publications and source records attributed to Lay, N..
Benefits to society of bioinspired flight capabilities
This paper highlights how in just about 100 years since the first successful flight took place at Kitty Hawk, our recent developments using inspiration from biology are enabling us to demonstrate flight capability for Mars exploration.
Ultra low power radiation tolerant UHF radio technologies for in situ communication applications
For future deep space missions, significant reductions in the mass and power requirements for short-range telecommunication systems will be critical in enabling a wide variety of new mission concepts. These possibilites include penetrators, gliders, miniature rovers and sensor networks.
A Real-Time Testbed for Satellite and Terrestrial Communications Experimentation and Development
This paper describes a programmable DSP-based testbed that is employed in the development and evaluation of blind demodulation algorithms to be used in wireless satellite or terrestrial communications systems.
A Real-Time Testbed for Satellite and Terrestrial Communications Experimentation and Development
This paper describes a programmable DSP-based testbed that is employed in the development and evaluation of blind demodulation algorithms to be used in wireless satellite or terrestrial communications systems. The testbed employs a graphical user interface (GUI) to provide independent, real-time control of modulator, channel and demodulator parameters and also affords realtime observation of various diagnostic signals such as carrier, timing recovery and decoder metrics. This interactive flexibility enables an operator to tailor the testbed parameters and environment to investigate the performance of any arbitrary communications system and channel model. Furthermore, a variety of digital and analog interfaces allow the testbed to be used either as a stand-alone digital modulator or receiver, thereby extending its experimental utility from the laboratory to the field.
Combined trellis coding and feedforward processing for MSS applications
The idea of using a multiple (more than two) symbol observation interval to improve error probability performance is applied to differential detection of trellis coded MPSK over a mobile satellite (fading) channel. Results are obtained via computer simulation. It is shown that only a slight increase (e.g., one symbol) in the length of the observation interval will provide a significant improvement in bit error probability performance both in AWGN and fading environments.
Description and performance of a digital mobile satellite terminal
A major goal of the Mobile Satellite Experiment (MSAT-X) program at the Jet Propulsion Lab (JPL) is the development of an advanced digital terminal for use in land mobile satellite communication. The terminal has been developed to minimize the risk of applying advanced technologies to future commercial mobile satellite systems (MSS). Testing with existing L band satellites was performed in fixed, land mobile and aeronautical mobile environments. JPL's development and tests of its mobile terminal have demonstrated the viability of narrowband digital voice communications in a land mobile environment through geostationary satellites. This paper provides a consolidated description of the terminal architecture and the performance of its individual elements.