Motorola

About: Motorola is a company organization based out in Schaumburg, Illinois, United States. It is known for research contribution in the topics: Signal & Communications system. The organization has 27298 authors who have published 38274 publications receiving 968710 citations. The organization is also known as: Motorola, Inc. & Galvin Manufacturing Corporation.

Method and apparatus for assisted GPS integrity maintenance

Abstract: A cellular network protocol which maintains the reliability of assisted GPS based positioning is taught. An Integrity Monitor (IM) informs mobile stations, their users, or networks of measurement quality and it warns them of failing and failed GPS satellites by isolating them from the effects of these failures. Whenever an unhealthy satellite is detected, its corresponding assistance data will be excluded for delivery or for position determination. In other words, there are two specific aspects to the Integrity Monitor (IM). For DGPS users, it predicts the reliability or quality of the DGPS corrections. For all users, it isolats the mobile position calculation from the effects of GPS satellite failures. The UDRE parameter, nominally output by a reference DGPS receiver, is used to communicate the DGPS quality information, and DGPS corrections are simply excluded for failed satellites. For autonomous GPS users, a special integrity message is required and defined to communicate the satellite failure status information.

Antenna array for a cellular RF communications system

Abstract: An array of antennas for a cellular RF communications system for providing communications to randomly placed transceivers in a given area. The antenna array includes a plurality of antenna sites located in the centers of cells. Each antenna site has a plurality of sectored antennas for providing a plurality of communication channels. A predetermined number of sites are used to constitute a subarray of cells to provide a set of communication channels and channel allocations are repeated from subarray to subarray. Channels are also so allocated as to minimize channel interference and optimize channel utilization. An omnidirectional antenna may be provided for each antenna site for signalling purposes.

High efficiency power amplifier using combined linear and switching techniques with novel feedback system

Abstract: An amplifier (100) includes an output node (114) having an output voltage (Vout), and a switching amplifier (104) having a first output (132) coupled to the output node for delivering a switching amplifier output current (ISW) to the output node. The amplifier further includes a modulator (136) coupled to the switching amplifier for controlling the switching amplifier, and a linear amplifier (102) producing a linear amplifier output current (Ilin) through a second output (118) coupled to the output node. The amplifier also includes a feedback network (106) coupled to the modulator for controlling the modulator, the feedback network also coupled to a reference signal (Vref) which the amplifier apparatus tracks, the feedback network further coupled to a current sense signal (Isen) proportional to the linear amplifier output current, and coupled to a switching amplifier signal (Vint) internal to the switching amplifier, the switching amplifier signal not derived from the output voltage and not generated by sensing the switching amplifier output current.

Method and apparatus for multiple frequency RFID tag architecture

Abstract: The present invention provides a multi-band, multi-mode RFID tag that uses a single antenna structure and integrated circuit to provide asset location information at any stage of a supply chain. The unified tag design operates at multiple frequencies (or bands) using the antenna structure, for example, 125 kHz, 13.56 MHz, 915 MHz, and 2.45 GHz, and preferably operates electrostatically (at lower frequencies) and electromagnetically (ay higher frequencies). An on-chip frequency monitor in the integrated circuit automatically determines which frequency is present and derives a local clock for the tag's integrated circuit, which can vary in accordance with the frequency or which can be constant. Alternatively, a phase locked loop circuit can be used to derive a local clock signal modulated into the interrogation signal. On-chip matching and power extraction circuits derive power for the tag from the interrogation signal, which is preferably passive. Additionally, a receiver can receive data from the interrogation signal.

Multiple frequency message system

Abstract: A multiple frequency message system (300) comprises at least a transmitter (508) for transmitting coded signals on a plurality of channels (102, ..., 108) of which at least one channel to be assigned to each of a plurality of geographical areas (302, 304, 306) and at least a receiver (400) capable of receiving the coded message signals during a predetermined coded transmission slot (110) being transmitted on the plurality of channels (102, ..., 108). The coded message signals include channel identification information (208) and message information (210) being transmitted in a sequence of coded transmission slots on each of the plurality of channels (102, ..., 108), the sequence of coded transmission slots are transmitted offset in time such that a particular transmission slot is not simultaneously transmitted on any of the plurality of channels (102, ..., 108). The receiver (400) further comprises a channel selecting circuit (426) responsive to not detecting the predetermined channel identification information during the predetermined transmission slot on a predetermined transmission slot on a predetermined channel, for thereafter sequentially receiving the predetermined transmission slot on each of the plurality of channels (102, ..., 108).