First Pacific Networks

Ford Aerospace & Communications Corporation

Other

Ge Capital Spacenet Services, Inc.

Michael J Serrone

Robert P McNamara

Gary L Wagner

Chinh Q Phan

David E Hansen

Norman Franklin Krasner

Philip M Freidin

James C Long

Michael Aaron Siegel

Robert Yarbrough

Long K Tran

William G Howell

Timothy P Halloran

An alert transceiver in commuter vehicles in a line-of-site warning area receive line of sight (LOS) alert signals from another vehicle, such as an emergency vehicle. Upon detecting the LOS alert signal, the alert transceiver can relay the alert signals to other alert transceivers in commuter vehicles within a warning zone that are outside of LOS zone, thereby creating mobile tracking network (MTN). The alert signals can include any relevant information, such as information regarding a hazard that includes the type of hazard (emergency vehicle, fire, ambulance, etc.), the time stamped location, direction of travel, speed and planned route for the emergency vehicle; and/or the coordinates of warning zone as determined by alert transceivers.

Emergency vehicle alert system

A programmable digital correlator device, and associated correlation method, with a very efficient structure. In one aspect, two or more correlators share a common data sequence shift register. In another aspect, the data sequence shift register is comprised of random access memory (RAM) modules which allow efficient construction in field programmable gate array (FPGA) logic devices. Two's-complement data samples are multiplied by a reference sequence to produce unfinished two's-complement products, the products are summed with unsigned arithmetic in an adder containing population counters, and a correction factor is added after all other calculations are complete to convert the unsigned result back to a two's-complement number.

Correlator method and apparatus

A baseband signal is spectrally efficiently transmitted on a broadband transmission medium by inserting gaps in packets of digital data transmitted in a modulated first radio frequency carrier. The transmitted packets of data are received by demodulating the modulated first radio frequency carrier, and the gap is monitored for the presence of digital data thus indicating a collision of simultaneously transmitted packets of digital data. A seed of arbitrary digital bits are used in scrambling each packet of digital data and is transmitted with the packet of data for use in descrambling the data. In retransmitting the packet of data the seed is included. The originally transmitting node receives the retransmitted packet and compares the retransmitted seed with the originally transmitted seed for detecting an error in retransmission.

Spectrally efficient broadband transmission system

Apparatus for combining broadband RF signals and baseband signals in a baseband distribution cable includes a bridge for coupling the distribution cable to an RF broadband trunk and to a baseband repeater. The trunk is connected through bidirectional amplifier, an impedance transformer, and a signal splitter for applying the amplified and impedance transformed broadband signal to a plurality of baseband segments. The RF signal from the splitter is passed through a 35 MHz high pass filter to the baseband segment. Baseband signals from a repeater are passed through a 25 MHz low pass filter to the baseband segment. The two filters prevent interference between the baseband and broadband signals. A tap in the distribution cable for accessing the broadband and baseband signals includes first and second low pass filters and a directional coupler serially connected between two cable terminals with a high pass filter connected in parallel with a first and second low pass filters whereby broadband signals can pass around the low pass filters. A third low pass filter connects an MAU port to the first and second low pass filters whereby baseband signals can be transmitted in either direction on the distribution cable without injecting noise in the broadband signal.

Apparatus for combining broadband and baseband signal transmissions

A method and an apparatus for demodulating M-ary PSK signals of the type wherein the modulation is limited to phase transitions between adjacent phase states. The method is operative in a demodulator which comprises a phase splitter dividing a source signal into two paths with a preselected phase relationship among phases, one of the phases being delayed by nominally one bit period, a mixer or multiplier receiving as one input a representation of the delayed-phase component and as a second input a representation of the other phase component. A signal is filtered by a lowpass filter and provided to at least one corresponding two-level comparator, each of which produces a digital output. Digital logic circuitry responds to the digital outputs of each of the comparators to map the digital outputs into a single digital bit stream of ones and zeros.

Method and apparatus for demodulating a class of M-ary phase shift keyed

A lock detector (12) used in conjunction with a bit synchronizer (14) for determining when a random binary input signal (2) is in lock with a clock (7) generated by the bit synchronizer (14). A window comparator (3, 5; or 23, 25, 27) determines whether the amplitude of the input signal (2) is within or without an amplitude window, and generates a signal (33) as a result of said determination. This signal (33) is sampled at periodic sampling points (X, Y). The set of X sampling points and set of Y sampling points are interleaved and usually separated by half a bit period. The X samples and Y samples are averaged and compared. Means (19) are provided for declaring a lock condition when the X average exceeds the Y average by a preselected threshold (V.sub.REF), which occurs when the X points are positioned near mid-points of data bits (35) and the Y points are positioned near data transitions (39). The circuit (12) will not lock on false sidebands and can operate at very low signal-to-noise ratios.

Lock detector for bit synchronizer

A dynamic electronic switch (10) having n inputs (2) and m outputs (4), where n and m are any positive integers. The electromagnetic signal on any given input (2) may be switched onto any number of outputs (4), but any given output (4) may have no more than one input signal switched thereonto at any given time. Switching nodes (8), comprising at least one switching diode (11, 13, 15) and a directional edge coupler (17) embedded between two parallel ground planes (9, 1) in a planar mother board (5), perform switching at each intersection of an input (2) and an output (4). Each output (4) is mounted on a planar dielectric summer board (6) positioned orthogonal to the mother board (5). The lengths of the extended transmission lines (76) associated with each output (4) are such that when an input signal is switched onto said output (4), the sum of the admittances of the n-1 unswitched extended transmission lines ( 76), measured between an associated summing junction (85) and ground, is substantially equal to zero.

Growing community of inventors

Sunnyvale, CA, United States of America

Michael J Serrone