Abstract:
The present invention provides a manufacturing process (600) and method (500) for efficiently providing a multi-holographic optical element substrate unit (300). Upon preparation of an original continuous/non-continuous holographic optical element (201) with uniform diffraction efficiency and marking the original continuous/non-continuous holographic optical element (201) with predetermined alignment marks (206), the original continuous/non-continuous holographic optical element (201) is cut into a predetermined number of individual holographic optical elements (204) in accordance with the predetermined alignment marks (206). Then, a substrate (304) is prepared with alignment marks (302) in accordance with the predetermined alignment marks (206) of the individual holographic optical elements (306), and the individual holographic optical elements (306) are attached to a substrate (304) in accordance with the alignment marks (206 and 302)'alignement (206 et 302).
Abstract:
A temperature compensation (TC) circuit (10) for a crystal oscillator module (12) used in a communication device (200). An existing microcontroller (210) of the communication device (200) is used to provide TC digital data (30) for a crystal oscillator (18). In this way, the crystal oscillator module (12) does not require an on-board memory which substantially cuts costs. TC digital data (30) is converted to a TC signal (22) in a digital-to-analog converter which controls the crystal oscillator frequency. To compensate for radio voltage regulator variations over temperature, the crystal oscillator module (12) includes an on-board voltage regulator (34) which supplies a characterized regulated voltage (36) to the digital-to-analog converter such that the TC signal (22) from the digital-to-analog converter is inherently corrected for voltage variations in the voltage regulator (34). This improves stability of output frequency (20) from 5 ppm to about 2 ppm.
Abstract:
A controller (122) that dynamically configures a number of channels within a communication system (102) having a predetermined bandwidth comprises a processor (710) and memory (714), wherein the processor is programmed to receive a channel request from a subscriber unit for an inbound transmission of information. The processor (710) is further programmed to determine a type of information to be transmitted from the channel request and configure the predetermined bandwidth to be transmitted from the subscriber unit.
Abstract:
A communication system (10) has a selective call device (100) that transmits a frequency hopped spread spectrum signal encoded as a Reed Solomon code word and modulated as a four-level frequency shift keying (4FSK) signal. A transceiver (156) receives the signal on a plurality of narrow band channels in a pseudo random sequence. A DSP (152) performs a fast fourier transform on the signal. The DSP (152) has a comparator that computes and compares a 4FSK symbol to a jamming threshold and establishes a ratio of a maximum energy and a next to largest energy to an eye-opening threshold to indicate a probability of error. A determinator (334) determines when there is a jamming signal and in response to the probability of error determines when there is a fading signal in the narrow band channel. An erasure marker (346) marks a position as an erasure and an error encoding code (348) corrects errors marked as erasures.
Abstract:
A transceiver (10) used in an RF messaging system transmits unscheduled messages on a channel selected by the transceiver (10). The transceiver (10) examines a number of factors prior to selecting a channel, including the power available from its battery (39), the power required to send the message, and which channel it had previously used to successfully transmit a message. Depending on the results of this examination, the transceiver (10) can reject the channel it has used successfully on previous occasions and select a different channel having a different data rate.
Abstract:
A solenoid driver (10) capable of detecting the operational status of a solenoid (12) including the position of an armature within a solenoid coil and an operational method. The solenoid driver (10) generates a first solenoid current within the solenoid (12) and measures a first decay time t1. The first solenoid current is insufficient to pull the armature into the coil of the solenoid (12). A comparator circuit (22) continuously monitors the solenoid current and initiates a timer within a counter circuit (34) to compute the first current decay time. A second solenoid current is generated within the solenoid (12) that is sufficient to pull the armature into the coil of the solenoid (12). The second solenoid current is turned off and a second decay time t2 is measured. The decay times are stored in storage registers (R1, R2) within a controller (36). The controller (36) compares the measured decay times with stored values and outputs the armature position information over a communications bus (34).
Abstract:
A holographic optical interconnect system (100) and method (200) provide flexible, efficient interconnection of a plurality of circuit boards CBs and a plurality of integrated circuit chips. Each CB has at least an optically transparent substrate OTS mate parallel to the CB and extending outside a CB holder. Each OTS mate has parallel sides and carries at least two holographic optical elements HOEs. A first one of the HOEs on a first OTS mate reflects at least a predetermined portion of a first light beam transmitted by a transmitter on a corresponding CB to another HOE, which transmits a received light beam via free space outside the CB holder. On another OTS mate, two HOEs are utilized to receive and direct at least part of the light beam received to a detector on a corresponding CB via free space within the circuit board holder or reflection within the OTS mate.
Abstract:
Signal points are chosen from a fixed set of signal points (710, 725), such as exists in the baseband signal points found in PSTN compounding algorithms. These signal points are assigned to subsets (A, B, C, D) and transmitted according to a predefined transmitter state sequence, representable as a trellis diagram. The subsets may overlap by sharing signal points. The sharing of signal points improves the transmission performance of the arrangement in comparison to conventional disjoint sets. The signal points are selected and associated with subsets, such that the signal points transmittable from a given transmitter states maintain a minimum distance of d, even though the full combination of signal points of all subsets need not satisfy a minimum distance of d/2. From time to time, disjoint subsets may be used to preclude decoding problems resulting from the quasi catastrophic aspects of the resulting code.
Abstract:
The method operates in a system including a switching center (212), a base station (312) responsive to the switching center and a mobile communication unit (320) responsive to the base station, and includes receiving a first message (52) from the mobile communication unit; in response to the first message, determining whether the mobile communication unit is fraudulent; based on the determination, receiving a second message (55) at the switching center from a dedicated fraud indicator wireline connection (36); and in response to the second message, terminating the wireless communication of the mobile communication unit.
Abstract:
A selective call device (100) has a plurality of first alerts and a second alert and includes a decoder/controller (106) generating a plurality of icons associated with the plurality of first alerts and the second alert (116) and a switch for selecting an alert. The decoder/controller (106), in response to the switch (118), positions a second alert icon adjacent to a selected icon when the selected icon is not the second alert icon. A display (108) displays the second alert icon adjacent to the selected icon and the decoder/controller (106) regenerates the plurality of icons wherein the second alert icon is repositioned adjacent to a reselected alert icon.