Abstract: A missile is tested by first stimulating the performance of missile built-in tests that are stimulated in service by signals from the launch site, and which tests do not require internal access to the missile. If performance is satisfactory, no further testing is required. If a condition of unsatisfactory missile performance is detected, an access cover is removed, connections are made to internal sources of data, and the built-in tests are repeated in order to determine which internal components caused the unsatisfactory missile performance. The component is repaired. The testing with the access cover removed is repeated, and, if the performance is satisfactory, the access cover is replaced and the testing with the access cover present is repeated.

Abstract: The present invention relates to an apparatus and method for voltage regulation. The apparatus includes an error amplifier circuit in communication with an external reference voltage input. The error amplifier circuit produces an error voltage that is proportional to the difference between an external reference input voltage and an output voltage. A series pass circuit is in communication with the error amplifier circuit and is responsive to the error voltage. The method comprises the steps of comparing an external reference voltage to an output voltage, generating an error voltage proportional to the difference between the external reference voltage and the output voltage, and regulating the output voltage based upon the error voltage.

Abstract: A method for increasing the high mobility capacity of a personal access communications system (PACS) includes provides high and low tier channel links to service high and low speed subscriber units, respectively. The subscriber units determine their relative speed and select from among the high and low tier channels available to them based upon self-determined velocity and signal quality measurements.

Abstract: A method and system for adjusting the transmission power of a transmitter during a communication with a receiver in a mobile satellite communication system is disclosed herein. The method comprises establishing at least one threshold signal strength value for a transmitted burst; measuring the received signal strength of the burst received by the receiver; comparing the received signal strength with the threshold value; and setting a power control bit based on the comparison.

Abstract: A method of converting GMSK modulated signals arriving at an integer multiple of the IS-54 standard sampling (or symbol) rate (24.3 KHz) to GMSK modulated signals at an integer multiple of the CDPD standard sampling rate (19.2 KHz). In the preferred embodiment, the GMSK signals arrive as serial in-phase (I) samples and quadrature-phase (Q) samples at the IS-54 sampling rate. The method of the present invention combines into one calculation the following operations 1) time-alignment of the serial I and Q samples into IQ pairs, 2) conversion of the time-aligned IQ pairs to the CDPD sampling rate of 4.times.19.2 KHz, and 3) sign correction of each time-aligned IQ pair. Because of the periodic nature of certain variables in the above calculation, efficiency is further achieved with the present invention by storing tables containing the possible values of these variables, then using pointers to access the stored values as needed, thereby saving considerable processing power and time.

Abstract: A system and method for jointly determining initial tap coefficients for a maximum likelihood sequence estimating equalizer and a timing error of an incoming signal, in one embodiment, receives the incoming signal into a receiver, and locates a known portion within a time frame of the incoming signal. The known portion is compared with a stored representation of the known portion, and with a stored representation of a derivative of the known portion. The initial tap coefficients and timing error of the incoming signal are jointly determined based on the comparing of the known portion with the stored representations, and a subsequent known portion is located within a subsequent time frame of the incoming signal based on the timing error. The initial tap coefficients are passed to a maximum likelihood sequence estimating equalizer.

Abstract: A pitch estimating method includes the steps of (1) determining a set of pitch candidates to estimate a pitch of a digitized speech signal at each of a plurality of time instants, wherein series of these time instants define segments of the digitized speech signal; (2) constructing a pitch contour using a pitch candidate selected from each of the sets of pitch candidates determined in the first step; and (3) selecting a representative pitch estimate for the digitized speech signal segment from the set of pitch candidates comprising the pitch contour.

Abstract: A multisubscriber unit is disclosed for use of in a digital cellular communication system to communicate with a base transceiver station and eventually to switched telephone network. The multisubscriber unit connects to a plurality of individual subscriber telephones. It includes a plurality of upconverters, modulators, downconverters, demodulators speech compressors, speech decompressors, and voice activity detectors that are assigned to a subscriber telephone upon detection of an off hook signal from the telephone. Preferably, upon the detection of data to be transmitted, to channel allocation is requested from a pool of time division multiple access channels in a digital speech interpolation pool.

Abstract: A printed circuit board intended to be placed within a card slot of a personal computer that allows the personal computer to receive information directly from a satellite communication network. The adaptor card operates in slave mode to a CPU of the personal computer. The CPU receives demodulated signals from a demodulator of the adaptor card via a bus interface on the adaptor card. The CPU also receives status information for the demodulator and a tuner and controls the operation of the demodulator and tuner via the bus interface. A DC-DC converter receives power from a power supply of the personal computer via the bus interface and provides power for the adaptor card circuitry. Moreover, the DC-DC converter powers a low noise block (LNB) of an antenna of the satellite communication network.

Abstract: A method and apparatus for unambiguous, precise and self-calibrating detection of unreliable semiconductor operation is provided. The apparatus includes an optically coupled sensor positioned over a semiconductor device and an electrical feedback control loop for adjusting the operating range of the semiconductor device. The method includes the steps of measuring optical emissions from a semiconductor device and adjusting compensation circuitry connected to the semiconductor device in response to the measured emissions.

Abstract: An apparatus for generating an on-screen television program guide. The apparatus generates a main menu of a program guide, which includes program source information and program event information for a plurality of program sources, and further generates navigation menus for allowing a viewer to modify the program guide. The navigation menus are generated so as to over-write only a portion of the main menu of the program guide.

Abstract: A system and method that provides an electronic indication that unauthorized access has been gained to a system. The mechanisms used by the present invention cannot be forged, bypassed, or subverted. In fact, even persons authorized to access the environment cannot do so without leaving evidence. When an intrusion is detected, a random number is generated. This random number, referred to as an audit count, is then encrypted and stored, and a sequence number is incremented. To recover this information at a later time, a trusted individual inserts an external device containing a decryption key. The decryption key is extracted, and the encrypted audit count and sequence number are decrypted and displayed. Periodic verification that the audit count and sequence number have not changed provides assurance that access has not been gained to the system.

Abstract: A method of detecting narrow-band signals in an echo canceller to control the coefficient update process, echo suppression process, and the disablement of the echo canceller is provided. The method includes the steps of searching for the presence of a generic tone, searching for DTMF tones, searching for a 2100 Hz tone and, if a generic tone is found, searching for a dial tone. If a generic tone is detected on the far end signal, a tone flag is set which triggers the disablement of the echo canceller coefficient update process and the enablement of the echo suppressor process. If a 2100 Hz tone is detected, the echo canceller is disabled. If a DTMF signal is detected, DTMF flags are set which are used by the echo suppressor for suppressing the near end echo. Finally, if a dial tone is detected, dial tone flags are set which cause the disablement of the echo suppressor.

Abstract: The present invention provides a medium access control (MAC) layer in a mobile satellite system. The MAC transfers data across the physical channels in the air interface between the mobile terminals, the satellite and the gateways. The MAC of the present invention optimizes for satellite propogation delays and hides the physical transmission media from higher network layers.

Abstract: A dispatch system and a cellular interconnect system are combined to form a single system in which dispatch and interconnect communications are made with use of common system equipment. Different system configurations are employed according to the number of cells in the system to minimize loss of cellular interconnect capacity arising from dispatch communication operations.

Abstract: A remote ground terminal for transmitting a modulated data signal to a satellite. The remote ground terminal includes an outdoor unit comprising an input port for receiving a modulated data signal, a housing having an upper portion and a lower portion which comprises a waveguide. The outdoor unit further comprises a transmitter module for amplifying and multiplying the modulated data signal so as to produce the modulated carrier signal. The transmitter is mounted in the lower portion of the housing so as to be positioned above at least a portion of the waveguide. The outdoor unit also comprises a probe having a first and second end, with the first end being disposed in the transmitter module. The probe receives the modulated carrier signal generated by the transmitter module. The second end of the probe extends from a lower surface of the transmitter module into the waveguide.

Abstract: A receiver in a digital cellular communication system includes a system for receiving a signal transmitted in the cellular system and representing a code word encoded in a binary linear block code and a first digital signal processor for demodulating the signal and a second digital signal processor for decoding the binary linear block code in the demodulated signal. A system operates the digital signal processors to demodulate the code word partially and produce a demodulated portion of the code word, to provide a partial syndrome calculation to the demodulated portion of the code word as at least one additional portion of the code word is demodulated, and to apply an additional syndrome calculation to the at least one additional demodulated portion of the code word, and to combine the partial and additional syndrome calculations to provide a complete syndrome calculation. An output system then outputs decoded signals.

Abstract: VHF DC to AC inverters which include switching circuitry (13, 115, 125) and multiple resonant waveshaping networks (C11, L11, C12; C21, L21, C22; C111, L111; C221, L221; C331, L331; C441, L441) connected between the switching circuitry and respective load circuits (33, 43, 133, 143).

Abstract: A system and technique for directing intensity modulated electromagnetic energy. The inventive system (10) includes an intensity modulated source of electromagnetic energy (12). Individual elements (22) in an array of energy directing elements (15) are activated in sync with the modulation of the energy source (12). In a particular implementation, the source (12) is a laser. The intensity of the laser is reduced during each successive field per frame. The energy directing elements (15), in this case, light directing elements, are implemented with an array of digital micromirrors. The light source (12) is modulated in intensity in accordance with a fixed modulation scheme. The mirrors (22) are selectively activated relative to the light source modulation scheme. Hence, the invention provides a gray scale output while allowing the time between mirror flips to be constant.

Abstract: A prepreg thermoset sheet, ready to be cured, is molded with a preprocessed thermoplastic part to form an integral thermoset/thermoplastic composite joint. The composite produces a more robust access panel. The thermoplastic part is more damage tolerant and easy to repair. The thermoset part, while more difficult to repair, is cheaper than the thermoplastic part and thus used in those places where damage is not likely to occur. The method of molding the two parts together comprises: (a) providing a first part comprising the thermoset resin and a second part comprising the thermoplastic resin, both resins being partially miscible in each other; and (b) forming an interface between the first and second parts by bringing the parts into mutual contact and heating the parts at a temperature and pressure for a period of time sufficient to promote mutual miscibility prior to forming a network structure in the thermoset resin.