Abstract: A GNSS receiver and method using alternating “A” and “B” time segments for a reception time length of two or more data bits. The GNSS signal in an “A” time period comprising the “A” time segments is integrated for determining “A” magnitudes corresponding to code phase increments and the GNSS signal in a “B” time period comprising the “B” time segments is integrated for determining “B” magnitudes corresponding to code phase increments. A trial-and-error data bit search is performed for depolarizing data bit senses. The code phase increment showing the largest correlation level is used for acquisition of the GNSS signal and/or determination of the location where the GNSS is being received.
Abstract: A generic navigation satellite system (GNSS) signal receiver having a fast time to first fix by calibrating a low power always-on real time clock (RTC). The receiver includes an RTC calibrator having a fraction calculator. The RTC calibrator may also include a time expander. Before the receiver is powered off, the fraction calculator uses the fine resolution of GNSS time for determining a time fraction for RTC time. When the receiver is powered back on, the time expander uses an estimate of RTC time drift during the time that GNSS receiver had power off and the time fraction for calibrating and increasing the resolution of the RTC time for an RTC time tick. A signal navigation processor uses the calibrated RTC time for assisting a first fix with code phase search, integration time periods, resolution of epoch integer and/or location-in-space of GPS satellites.
March 13, 2009
Date of Patent:
September 7, 2010
Trimble Navigation Limited
Xiaorong Zhi, Yiming Yu, Joseph W. Fontes
Abstract: A GPS receiver and method using alternating “A” and “B” integration time segments. The polarities of certain GPS data bits are known beforehand and their expected reception times are known. The GPS signal in 10 millisecond “A” time segments and “B” time segments is depolarized according to the known polarities. The depolarized GPS signal during an “A” time period made up of all the “A” time segments is integrated for providing an “A” time period magnitude for each code phase. Likewise, the depolarized GPS signal during a “B” time period made up of all the “B” time segments is integrated for providing a “B” time period magnitude for each potential GPS code phase. The strongest of the time period magnitudes is compared to a correlation threshold for selecting a code phase for signal acquisition.
Abstract: A GPS receiver having a ratio-based signal acquisition method. The GPS receiver has a tentative signal acquisition when a first ratio of the largest GPS signal correlation value to the second largest in a first time period exceeds a selected qualification ratio. The GPS receiver verifies signal acquisition when the average of iteration ratios for largest to second largest correlation values in iteration time periods exceed the qualification ratio.
Abstract: A method and apparatus for reducing nonlinear phase noise that is induced in an optical transmission system by the interaction of optical amplifier noise and Kerr effect. The apparatus includes an intensity-scaled nonlinear phase noise compensator. The phase noise compensator reduces the nonlinear phase noise by rotating a phase estimate by a scaled signal strength estimate for the optical signal or by comparing a complex estimate to curved regions having scaled nonlinear decision boundaries. The scale factor is derived from the number of spans in the transmission system. Another embodiment of the phase noise compensator uses the scaled signal strength for re-modulating an optical signal.
Abstract: A GPS receiver for integrating a GPS signal separately in a series of “A” type and “B” type time segments, the “A” segments alternating with the “B” time segments; combining the squares of the magnitudes of “A” time segment integrations corresponding to code phases for forming “A” type combined magnitudes; combining the squares of the magnitudes of the “B” time segment integrations corresponding to code phases for forming “B” type combined magnitudes; and determining an acquisition code phase of the signal from the strongest of the “A” or “B” combined magnitudes. The “A” time segments and the “B” time segments are one-half the period of the data bits of the signal, thereby ensuring that either the “A” time segments or the “B” time segments avoid the nullifying effect of data bit inversions.
Abstract: A reversible solenoid that can be easily changed over between active push and active pull. The solenoid includes a coil and an armature that may be assembled for an active push or an active pull of a latch member. The coil has a front end and a rear end. The front coil end always faces toward the latch member and the rear end always faces away from the latch member. The armature includes a magnetic slug. The slug is disposed at the rear coil end for the active push mode or disposed at the front coil end for the active pull mode.
Abstract: A hierarchical display of protocol layers for communication data. Fields of the communication data are converted into field cells where each field cell has a text field and a field descriptor. The field cells for each protocol layer are arranged by an interpreter into protocol units according to a protocol standard for that layer and then displayed in a hierarchical manner. Detailed specifications for field cells taken directly from the protocol standard can be displayed by using a cursor over the field cell. Indicators in particular ones of the field cells allow certain field cells within a protocol unit to be collapsed or expanded within the protocol unit or allow lower protocol units to be collapsed or expanded into the higher protocol units.
July 27, 2001
Date of Patent:
November 30, 2004
Computer Access Technology Corporation
Michael Pasumansky, Peretz Tzarnotsky, Valera Fooksman
Abstract: A radio system having a hub transceiver and a plurality of customer premise transceivers at different distances from the hub transceiver. Each of the customer premise transceivers includes an antenna for transmitting an upstream radio signal to the hub transceiver and receiving a downstream radio signal from the hub transceiver. A selected exchangeable attenuator pad is mounted on the customer premise antenna in the path of the radiated signals for attenuating the upstream and downstream radio signals. The attenuator pad is selected in order to compensate for the different transmission path losses in order to provide a fixed predetermined signal strength in the downstream radio signals to each of the customer premise transceivers and a fixed predetermined signal strength to the hub transceiver from each of the customer premise transceivers.
Abstract: A cellular telephone having a global positioning system (GPS) receiver using a blended combination of GPS signals from GPS satellites and GPS pseudolites for determining a location. The cellular transceiver receives wireless downlink cellphone signals having acquisition aiding information including GPS-based time; ephemeris orbital parameters for GPS satellites; and pseudorandom (PRN) codes, locations, and signal characteristics used by GPS pseudolites in the local vicinity. The GPS receiver in the cellular telephone uses the acquisition aiding information for speeding the time to the first location fix.
Abstract: An optical duobinary transmitter. The transmitter uses a half-rate precoder, half-rate non-linear modulation drive circuits and a multiplex modulator for generating duobinary modulation on an optical signal from which full-rate data can be detected without decoding.
Abstract: A method and apparatus for synchronizing with a network without connecting to the network by shadowing a slave device while a master device connects the slave device to the network. The master device maintains a system clock time. The master and slave devices exchange communication traffic during time slots on channels in a channel hopping sequence derived from the system clock time. The method and apparatus obtain a slave clock time in an inquiry response packet from a slave device when the master and slave devices are not connected in the network and then use the slave clock time for shadowing the slave device for receiving a master page frequency hop synchronization (FHS) packet having the system clock time.
Abstract: An MS DOS and MS WINDOWS compatible file system for avoiding loss of data in a memory unit if power is interrupted while new data is being written. The file system uses an ATA write command for erasing a data reserve sector and writing the modified data including the new data into the data reserve sector; erasing a control reserve sector and writing control data into the control reserve sector; erasing the intended operational sector and writing the modified data into the intended operational sector; and then uses an ATA erase command for erasing the control reserve sector. At power up or insertion of the memory unit, the control reserve sector is tested. If the control data is non-erased the host uses the copy of the modified data in the data reserve sector for replacing the data in the intended operational sector.
Abstract: An electrified mortise lock where the same method and articles can be used for electrifying the mortise locks of many manufacturers and styles. The electrified mortise lock includes a solenoid and a cradle. The cradle includes a frame for embracing the solenoid and cradle pins for fixing the solenoid to a housing.
Abstract: A GPS receiver having a fast acquisition of a GPS signal having a low signal-to-noise ratio. The GPS receiver uses an adjustable local frequency for iteratively downconvertig raw GPS signal samples to baseband GPS signal code data, combining a plurality of code epochs of the GPS signal code data in chunks and superchunks for providing representative code epochs, and correlates the representative code epochs to a replica code epoch for providing correlation times. Two or more correlation times are used to determine a correlation time difference. The correlation time difference is indicative of a residual frequency error. The error is used for correcting the local frequency. GPS pseudoranges are computed from the correlation times when the residual frequency error from the corrected local frequency is below a threshold.
Abstract: A system using coarse GPS orbital parameters for providing a precise GPS location. The system includes a GPS reference receiver and a GPS user receiver. Coarse locations-in-space of GPS satellites are computed from almanac or old ephemeris data. In a first embodiment the GPS user receiver uses DGPS corrections based upon the same coarse orbital parameters for providing a precise DGPS user location. In a second embodiment the GPS user receiver computes a coarse location from the coarse orbital parameters; and the GPS reference receiver recalculates the user pseudoranges using the same coarse orbital parameters and then uses the recalculated user pseudoranges for providing a more accurate user location.
Abstract: A monitor hinge having a magnet plug and a magnetic switch plug. The magnet plug and magnetic switch plug have countersink heads to seat in the hinge fastening holes and insert through juxtaposed hinge holes into drilled holes in the door and wall jambs.
Abstract: A method and apparatus for synchronizing with communication traffic in a BLUETOOTH network without joining the network. The apparatus transmits an inquiry signal and receives an inquiry response signal having a coarse system clock time. The apparatus uses the coarse system clock time for estimating an initial channel in a channel hopping sequence then advances channels through the sequence in steps of four or more for scan window time periods of four or more time slot periods until a communication traffic signal is recognized. The time-of-arrival of the traffic signal is used for refining the coarse system clock time in order to acquire the exact system clock time. The exact system clock time is used by the analyzer for deriving the channels and timing of the sequence for synchronizing to subsequent communication traffic signals.
Abstract: A method and apparatus for synchronizing with communication traffic in a network without joining the network. The method and apparatus synchronize to the communication traffic by mimicking a BLUETOOTH slave device in order to obtain a preliminary or unconnected system clock time in a master page frequency hop synchronization (FHS) packet from a BLUETOOTH master device when the master device is not connected to any BLUETOOTH slave devices, and then updating the preliminary system clock time with a time-of-arrival of a communication traffic packet from the master device after a connection is formed between the master device and a BLUETOOTH slave device.
Abstract: Methods and apparatus are described to transmit and receive information encoded in multilevel optical signals that take on at least three intensity levels. Intensity levels of a transmitted multilevel optical signal are optimized to minimize a transmitted optical power required to achieve a specified decision error probability, taking account of an arbitrary admixture of impairments, including signal-dependent noise, signal-independent noise, a finite transmitter extinction ratio, and intersymbol interference. The optimizations described are implemented using analytical or numerical techniques, depending on the admixture of impairments, and can be used to achieve equal or unequal decision error probabilities at a set of decision thresholds.