Abstract: A slot antenna has an array of slot pairs where the E-plane beamwidth of the transmitted energy can be controlled. The antenna includes at least one pair of slots which are fed by a microstrip, and electric field barriers positioned between and parallel to the slots. The electric field barriers extend between the front and rear panels of the slot antenna. The distance between the electric field barriers is used to adjust or tune the antenna to a particular transmit or receive frequency, and the distance between the slots is used to control the E-plane beamwidth of the transmitted energy. When the slots are placed closer together, the beamwidth becomes wider, and when the slots are moved further apart, the beamwidth becomes narrower. In one embodiment, the electric field barrier is a series of closely spaced conductors, and in another embodiment, the electric field barrier is a conductive strip.

Abstract: A compact high resolution omnidirectional or panoramic viewer has several cameras with a common virtual optical center. The field of view of each of the cameras is arranged to form a continuous 360 degree view of an area when taken as a whole. The cameras are positioned so that they each views a different reflective surface of a polyhedron such as a pyramid. This results in each camera having a virtual optical center positioned within the pyramid. The cameras may be positioned so that their virtual optical centers are offset from each other. The offsets produce narrow blind regions that remove image distortions received from the edges of the pyramid's reflective surfaces. The reflective pyramids may be stacked base to base or nested within each other to produce a more compact panoramic viewer. Using two or more reflective pyramids in such close proximity permits using many cameras with the same virtual optical center.

Abstract: A nearly spherical view is provided using five cameras. Four cameras provide a 360 degree view of an area using a four sided pyramid shaped element. The four sides of the pyramid shaped element are reflective and reflect images from four different directions. Each camera is positioned to receive a reflected image from one of the reflective sides of the pyramid. The four cameras are arranged so that they share a common virtual optical center. A fifth camera with a wide angle lens is positioned with the camera's optical center positioned at the common virtual optical center. The fifth camera has a view in the direction of the pyramid's base to provide a nearly spherical view when combined with the 360 degree view of the other cameras.

Abstract: Cameras are positioned so that they each view a different reflective surface of a polyhedron such as a pyramid. This results in each camera having a virtual optical center positioned within the pyramid. The cameras are positioned so that their virtual optical centers are offset from each other. The offsets produce narrow blind regions that remove image distortions received from the edges of the pyramid's reflective surfaces.

Abstract: A radio communication system includes an Interrogator for generating and transmitting a radio signal. One or more Tags contained within the radio communication system receive the radio signal. A Backscatter Modulator modulates the reflection of the radio signal using a subcarrier signal, thereby forming a reflected modulated signal. The Interrogator receives and demodulates the reflected modulated signal. Based upon the characteristics of the demodulated signal, the Interrogator can determine the identity of the Tag, and the relative velocity of the Tag with respect to the Interrogator. The Interrogator can also determine if motion exists in the vicinity of the Interrogator, even when no Tag is present, without the need for a separate motion detection system. The characteristics of the demodulated signal, can also be used to determine the characteristics of motion of the Tag, such as the vibrational frequency.

Abstract: A radio communications system is that can determine the location of an RFID Tag. The radio communication system includes at least one Interrogator for generating and transmitting a modulated radio signal to one or more Tags. The Interrogator is at a known location, and is in motion with respect to the Tag at a known velocity. One or more Tags of the system receive and demodulate the modulated radio signal, which contains a first information signal which specifies which Tag or Tags should respond using Modulated Backscattering. The Tag generates a subcarrier signal, and backscatter modulates the reflection of the radio signal using the subcarrier signal, thereby forming a reflected signal. The Interrogator receives and demodulates the reflected signal. The Interrogator then determines the Tag's relative direction from the location and velocity of the Interrogator, and from the Doppler shift of the subcarrier signal. More than one of such measurements allow the location of the Tag to be determined.

Abstract: Interference signal power in a TDMA communication system is determined by taking samples of a received signal. The TDMA system has a plurality of communication frequencies with sequences of frames communicated at each of the communication frequencies. Each of the frames contain a plurality of time slots, where each time slot is associated with a communication channel. The interference signal power is determined by receiving a signal at one of the plurality of communication frequencies. The signal is sampled for at least one frame period. The interference signal power is calculated using the M larger amplitude samples of the signal, where M is the number of samples that are taken during a period of time that corresponds to a length of one time slot.

Abstract: Four cameras provide a 360 degree view of an area using a four sided pyramid shaped element. The four sides of the pyramid shaped element are reflective and reflect images from four different directions. Each camera is positioned to receive a reflected image from one of the reflective sides of the pyramids. The cameras are arranged so that they share a common virtual optical center. Pixel data from the cameras is stored in a memory, and the data is selectively retrieved from the memory for viewing based on a user's input.

Abstract: A communication device locates a wireless service provider in a multi-service provider environment using a stored list of preferred service providers, the list has a plurality of uniquely identified sublists, each sublist is associated with a different geographic area and identifies a more preferred service provider and a less preferred service provider. Information received from an initial service provider is used to select a sublist from the plurality of sublists. A preferred service provider is selected by registering with an available service provider having a highest preference of available service providers as specified in the selected sublist.

Abstract: A system comprising a personal computer card and an interchangeable extension consists of a personal computer card a card information storage (CIS) system and a coaxial connection socket. First logic means are arranged to control an interrogation means comprising a digital-to-analog current converter, comparator and reference voltage source in order to supply a series of DC currents to the socket. The extension has a coaxial connection pin and grounded resistor having a value which identifies the type of extension so that when a DC current is applied to the pin by the socket, a characteristic voltage is generated across the resistor which is compared by the comparator with the reference voltage. The comparator indicates the value of resistor as a digital value to the CIS system which communicates the characteristics of the extension to a host PC. A second logic means disables power upon removal of a previous extension from the socket.

Abstract: A wireless communication system which is reconfigurable to accommodate varying traffic density is provided by using a flexible optical interface between a base station controller and several base stations. Communication between the base station controller and the base stations is provided over an optical fiber. The fiber carries several communication channels in both directions using wavelength multiplexing. The bandwidth between the base station controller and a particular base station is varied by increasing or decreasing the number of wavelengths used to communicate with the base station. Varying the bandwidth provides the ability to adjust the capacity to carry voice and/or data between the base station controller and the base station. As a result the number of radio frequency carrier frequencies assigned to a base station can be varied to support varying radio frequency traffic density throughout the wireless network.

Abstract: A flexible communications systems provides users with additional communication channels without requiring additional transmitters or receivers by using variable rate Walsh coding. Additionally, the assignment of these additional communication channels is easily managed at the base station by monitoring data backlog and receiver error rates.

Abstract: An embodiment of the present invention locates facial features in an image by bandpass filtering the image and then performing morphological operations followed by a thresholding operation. This initial processing identifies candidate areas where facial features may be located. The candidate areas are evaluated by classifiers to determine if a facial feature, such as an eye or mouth, has been located.

Abstract: A pyramid shaped group of reflective surfaces segment a field of view. Each of the reflective surfaces of the pyramid provides a segment of the field of view to a lens which focuses the segment onto a sensor. The pyramid shaped collection of reflective surfaces provide each of the sensors with a common center of projection. This avoids distortions that may result from using sensors with differing centers of projection. The sensors provide an electronic representation of the image for storage or other uses. The sensor used to receive each segment may have a low resolution, but since the low resolution sensor is only capturing a segment of the image, the overall effect is to capture the entire image at a high resolution.

Abstract: At the reception site of a laser transmission system the received laser light beam is converted into a focusing cone of light. The cone of light is directed to partially illuminate the inner area of the quad photo detector array which is used to provide a highly accurate positional measurement of the laser beam. A quad photo detector is utilized to measure deviation of the laser beam from its ideal line-of-sight and provide sensing signals defining the deviation to enable its corrective adjustment. A high speed photo detector located centrally to and behind a central aperture of the quadrant photo detector permits the detection of the laser light beam voice and data.

Abstract: Two binary two's complement numbers X and Y are compared using half-adders and a parallel prefix-and circuit to find a carry bit that results from forming the sum C+S, where C is the carry word and S is the sum word of the half-adder representation of X+Y. The carry bit is used to calculate the sign of C+S and the sign is used to determine whether X<Y, or X>Y. Additionally, the circuit also indicates when X=Y.

Abstract: Groups of symbols to be recognized are standardized by fitting four flexible curves to the group of symbols. The curves are fitted by minimizing a cost or energy function that associates a cost with the curvature of the curves, the slant of the curves, the displacement in spacing between the curves and the distance of maxima and minima points from the curves. After the curves are fitted to the group of symbols, the symbols are standardized by transforming coordinates systems so that the fitted curves are placed in a predetermined configuration.

Abstract: The invention relates to a multiwavelength add/drop multiplexer for use in an optical fiber communication system having a main optical fiber. The multiplexer includes an optical element, in the form of an optical circulator, arranged to direct substantially all of the light transmitted in a predetermined direction along the main optical fiber into a branch optical fiber regardless of wavelength. The branch optical fiber includes a transmission filter, in the form of a Fabry-Perot filter, arranged to transmit light of a predetermined wavelength and reflect the non-transmitted light back towards said main optical fiber for continued propagation along said main optical fiber. The multiplexer also includes a receiver for receiving the transmitted light, and further includes a transmitter arranged to transmit optical data signals along said branch optical fiber, through said transmission filter and towards said optical element, for propagation along said main optical fiber.

Abstract: Forgeries are detected by curve fitting the signature in question. The length of the curve fitted signature and the length of the signature in question are compared. If the signature in question is a traced or copied forgery, it will tend to have a significant amount of jitter which results in a significantly longer length than the curved fitted signature.

Abstract: Four cameras provide a 360 degree view of an area using a four sided pyramid shaped element. The four sides of the pyramid shaped element are reflective and reflect images from four different directions. Each camera is positioned to receive a reflected image from one of the reflective sides of the pyramids. The cameras are arranged so that they share a common virtual optical center.