EMS Technologies

About: EMS Technologies is a based out in . It is known for research contribution in the topics: Antenna (radio) & Printed circuit board. The organization has 100 authors who have published 104 publications receiving 4289 citations.

Method and system for communicating information in a digital signal

Abstract: The present invention relates to a communication method, system and signal, and in particular to a method and system for communicating information in a digital signal. It has particular application to satellite or terrestrial packet-based multi-user radio communication systems. A method for communicating information in a digital signal comprising data symbols is disclosed, wherein the information is encoded in a sequence characteristic of pilot symbols distributed amongst the data symbols, such that a receiver is able to determine the sequence characteristic and retrieve the transmitted information. The invention allows information to be encoded into a sequence characteristic of pilot symbols, rather than relying on modulating such information onto the pilot symbols themselves. This allows a significantly larger number of pieces of information to be transmitted than hitherto possible, and the technique is more resistant to large frequency errors than prior techniques.

Distributed architecture for a wireless data communications system

Abstract: A data communications system characterized by the combination of a base station connected to a plurality of repeaters for communicating with remote terminals in response to outgoing data from a host computer and for communicating with the host computer in response to incoming data from the remote terminals Each repeater is assigned a coverage area with in a predetermined communications area to support data communications with the remote terminals located within its coverage area In response to incoming data, a repeater conducts a signal amplification operation and outputs amplified incoming data to the base station via a first communications link The base station processes the amplified incoming data and, in turn, generates processed incoming data for distribution to the host computer via a second communications link The base station also processes the outgoing data from the host computer to generate processed outgoing data, and sends transmitted outgoing data to each repeater via the first communications link Each repeater connected to the base station can amplify the transmitted outgoing data, and outputs amplified outgoing data to the remote terminals within its coverage area

Vehicle mount computer with configurable ignition switch behavior

Abstract: A vehicle mount computer having a configurable behavior controlled by a vehicle's ignition switch. A user can configure the computer to perform an action, switch modes, or execute a software application in response to the ignition switch being pressed or the position of the ignition switch being adjusted. For example, the computer can be configured to switch to a standby mode or hibernation mode, shutdown, prompt the user to select an action, or do nothing in response to the ignition switch being placed in an off position. The ignition switch can be electrically coupled to an input of the computer so that the computer's operating system or another application can monitor the status of the ignition switch. The operating system or application can cause the computer to perform the configured response upon detecting a change in the ignition switch's position or an actuation of the ignition switch.

A shaped-beam microstrip patch reflectarray

Abstract: This paper describes a microstrip reflectarray antenna designed to produce a shaped-beam coverage pattern using phase synthesis. The concept is demonstrated with a Ku-band linearly polarized reflectarray designed to provide coverage of the European continent and measured results are compared to those obtained for a previously designed shaped-reflector antenna designed for the same coverage specifications. Results validate the shaped-beam reflectarray concept, although there are disadvantages to the reflectarray such as narrow bandwidth and reduced aperture efficiency that may offset the mechanical and cost advantages of the flat surface of the reflectarray.

Enhancements for tcp perfomance enhancing proxies

Abstract: A method and system is presented for the bi-directional transfer of data packets over a TCP communications system that can comprise both terrestrial and satellite links, using an enhanced flight protocol that, transparently to the end users, replaces the TCP over the congested satellite link portion of the system that accelerates the data delivery between end users and improves reliability of the data packet transmission. The invention eliminates the conventional TCP 3-way handshake and other associated time-delay procedures and replaces them with an improved use of performance enhancing proxies at either end of the satellite link that use a unique acknowledgement methods, data buffer storage and packet header field arrangement among the design features of a flight protocol method and system that accelerates data packet transfer with more efficient link capacity use and greater data throughput.