Abstract: Encoding and transmitting packet-switched, spread-spectrum data. Data are encoded for privacy and to restrict intelligent receipt of the data to the intended recipient. The encoded data are demultiplexed into sub-data-sequence signals. The sub-data-sequence signals are spread-spectrum processed and combined as a multichannel spread-spectrum signal. The multichannel spread-spectrum signal is concatenated with a header to make a packet-spread-spectrum signal. The packet-spread-spectrum signal is transmitted over radio waves to a packet receiver. The packet receiver obtains timing for the multichannel spread-spectrum signal from the header. The packet receiver depsreads the multichannel spread-spectrum signal, and multiplexes the despread multichannel spread-spectrum signal as received-encoded data. The received-encoded data is decoded by the intended recipient and may be stored in a receiver memory or outputted directly.

Abstract: An improvement for obtaining synchronization to a chip-sequence signal. The chip-sequence signal has a plurality of chips, and is embedded in a spread-spectrum signal. A shift register shifts or cycles a replica or delayed replica of the chip-sequence signal. The shift register has a plurality of taps, which correspond to the plurality of chips. A plurality of comparators compares the chip-sequence signal embedded in the spread-spectrum signal with the replica of the chip-sequence signal stored in the shift register. From the comparison, the plurality of comparators generates, for each tap of the shift register, a plurality of compared values at each comparator of the plurality of comparators. A plurality of counters up and down counts, from each comparator, a respective plurality of compared values. The respective plurality of compared values appears at an output of a respective comparator of the plurality of comparators. The plurality of counters thereby generates a plurality of totals, respectively.

Abstract: A system and method for handing off a remote unit from a first base station to a second base station, in a cellular spread-spectrum communications network, without loss of data. The remote unit transmits data to the first base station at a first data rate, and receives a first spread-spectrum signal having a first signal quality from the first base station. The remote unit monitors the first signal quality and compares the first signal quality to a plurality of signal qualities of a respective plurality of received-spread-spectrum signals. The remote unit initiates handoff when any of a number of predetermined criteria are met. Upon initiating handoff to the second base station, the remote unit stores the data that would otherwise have been transmitted. Once handoff is complete, the remote unit transmits the stored data to the second base station at a second data rate, with the second data rate greater than the first data rate.

Abstract: A system and method for encoding and transmitting data with a spread-spectrum time-division-multiple-access (SS-TDMA) system. Data to be transmitted by a SS-TDMA transmitter are sent within a particular specified group of time slots. Random packets also can be sent by transmission during an open time slot. The TDMA data are demultiplexed into sub-data-sequence signals, each of which are spread-spectrum processed and then combined as a multichannel, BPSK, QPSK or QAM spread-spectrum signal. The multichannel spread-spectrum signal is concatenated with a header to output a packet-spread-spectrum signal which is transmitted over radio waves to a packet receiver. The packet receiver obtains timing for the multichannel spread-spectrum signal from the header. The multichannel spread-spectrum signal is then despread and multiplexed as received-TDMA data. The received-TDMA data are selected from a particular time slot by the intended recipient and stored in a receiver memory for output.

Abstract: A spread-spectrum-phase-locked-loop apparatus and method for coherent detection without a pilot channel. The system comprises symbol-matched means, a voltage-controlled oscillator (VCO), a first product device, a second product device, a third product device, a fourth product device, a first combiner, a second combiner, and a fifth product device. The method comprises the steps of despreading, from a received spread-spectrum signal, an in-phase component and a quadrature-phase component of a symbol sequence signal using the symbol-matched means. The first and second product devices multiply the despread in-phase component by the VCO-cosine and the VCO-sine signals, respectively, to generate a first and a second product signal. The third and fourth product devices multiply the despread quadrature-phase component by the VCO-sine and the VCO-cosine signals, respectively, to generate a third and a fourth product signal.

Abstract: A spread-spectrum receiver for time sharing a correlator for simultaneously receiving a plurality of parallel spread-spectrum signals. A combined multiplicity of symbols includes a multiplicity of symbols, simultaneously occurring during a symbol-time duration, from a plurality of spread-spectrum signals. A demultiplexer demultiplexes a sequence of the combined multiplicity of symbols into a plurality of symbol registers. Each of the symbol registers stores the chip-sequence signals corresponding to the combined multiplicity of symbols which were sent to the particular symbol register. A multiplexer selects a symbol register, other than the symbol register selected by the demultiplexer. The multiplicity of chip-sequence signals stored in the selected symbol register by the multiplexer are compared by a comparator with a multiplicity of replicas of the chip-sequence signals used to generate the spread-spectrum signals.

Abstract: A system and method for transmitting a plurality of spread-spectrum signals over a communications channel having fading. The plurality of spread-spectrum signals are radiated by a plurality of antennas, with each antenna preferably spaced by one-quarter wavelength. A plurality of receiver antennas receive the plurality of spread-spectrum signals and a plurality of fading spread-spectrum signals. Each receiver antenna is coupled to a plurality of matched filters having a respective plurality of impulse responses matched to the chip-sequence signals of the plurality of spread-spectrum signals. A RAKE and space-diversity combiner combines, for each respective chip-sequence signal, a respective plurality of detected spread-spectrum signals and a respective multiplicity of detected-multipath-spread-spectrum signals, to generate a plurality of combined signals. The symbol amplitudes can be measured and erasure decoding employed to improve performance.

Abstract: A system and method using a Costas loop to effect accelerated convergence with minimal system complexity. The system comprises an in-phase-limiter and a quadrature-phase limiter, operatively coupled to an EXCLUSIVE-OR gate, for exclusively-ORing an in-phase-sign signal and a quadrature-phase-sign signal to output a first error signal, responsive to the signals having same signs, or a second error signal, responsive to the signals having different signs. An AGC circuit, operatively coupled to an output of the EXCLUSIVE-OR gate, increases and decreases a voltage level of an AGC signal responsive to two consecutive first or second error signals and consecutive dissimilar error signals, respectively. A voltage-controlled oscillator, operatively coupled to an output of the AGC circuit and responsive to the increased or decreased voltage level, changes the frequency of a voltage-controlled-oscillator output signal.

Abstract: A system and method for W-CDMA transmissions from the base to a remote unit and spread-TDMA transmissions from the remote unit to the base. By using spread-TDMA on the reverse link, limitations inherent with the use of CDMA due to non-zero cross correlation are avoided. The resulting system provides high quality performance in both directions.

Abstract: A combination bolt sizing tool comprising an upper surface plate, a lower surface plate, a pivot pin, a tensioning wheel and a plurality of bolt-sizer blades. The pivot pin connects the upper surface plate to the lower surface plate. The plurality of bolt-sizer blades are pivotally mounted by the pivot pin such that the free end of each blade may be rotated outward for use and then rotated back between the upper and lower surface plates. The tensioning wheel controls pressure on the blades, making them easier or harder to pivot.The free end of each bolt-sizer blade has a circular cutout of a specified diameter. The specified diameter of each bolt-sizer blade is different than the specified diameter of the circular cut-outs of other bolt-sizer blades. Each blade is visibly marked with the size of its respective circular cutout. The tool may include a second plurality of bolt-sizing blades, held by a second pivot pin, or a plurality of thread-pitch gauges held by the second pivot pin.

Abstract: A multi-clock matched filter for receiving signals with multipath. The signals may be modulated with a spread-spectrum spreading sequence, or other analog or digital signal. A number of signal registers store digital samples of the received signal. The gating of digital samples into each of the signal registers is controlled by a separate clock timing. The timing sequence may be derived from a common clock. A multiplexer sequentially selects each of the signal registers, and passes the respective content of each signal register to a matched filter. A number of delay-locked-loop circuits track each of the multipath signals, and generate the timing sequence for gating signal registers.

Abstract: A cleat for a conveyor belt, particularly for a vertical conveyor, with a cleat foot 2 attachable to the support side of the conveyor belt, and in which at least one anchoring member 5 is incorporated, and with a cleat section 1 forming a transverse wall of the conveyor belt, which is releasably attachable to the cleat foot 2 with the aid of the anchoring member 5. With the object of enabling a simpler attachment of the cleat section to the cleat foot, the anchoring member 5 is a rod, which extends transversely to the direction of travel 6 of the conveyor belt in the cleat foot 2. The rod may have threaded holes 12, which match holes 13 in the cleat foot 2 and holes 3 in the cleat section 1, through which screws 4 can be thrust in order to attach the cleat section 1. Alternatively, the rod may have bolts projecting radially therefrom, the bolts for extending through respective holes in the cleat section for securing the cleat section to the cleat foot with nuts.

Abstract: A system and method for performing multiplication and modular reduction of large integers. The system includes at least one large integer unit, each large integer unit having a multiplier, an adder, and a register. First and second multiplier inputs are applied to the multiplier, and first and second adder inputs are applied to the adder. One output of the multiplier is also applied to the adder. A plurality of large integer units may be connected into a large integer unit array that includes a complementing gate and a latching register. A second output of the multiplier is applied to the first adder input of a next large integer unit, with processing speed increasing as additional large integer units are added to the array.

Abstract: A system and method for synchronizing a Costas Loop for demodulating a received spread-spectrum signal having data and a first arbitrary phase angle, .phi.(t), using a phase detector, a phase unwrapping subsystem, an oscillator, a derotator and a decision device. A second arbitrary phase angle, .theta.(t), is generated from an in-phase component and a quadrature-phase component of the received spread-spectrum signal. The second arbitrary phase angle, .theta.(t), is proportional to the first arbitrary phase angle, .phi.(t). A value of .theta. proportional to .theta.(t) is then estimated. The estimated .theta. value is processed to obtain an estimate for the .phi.value, and a cosine and a sine of the estimated .phi. value are generated by the oscillator. The derotator derotates the in-phase-component and the quadrature-phase component of the received spread-spectrum signal with the cosine and the sine of the estimated .theta. value to generate a demodulated signal.

Abstract: A intelligent power management apparatus for use with a matched-filter. A multiplexer multiplexes shifted-in-phase chips and shifted-quadrature-phase chips from an in-phase-shift register and a quadrature-phase-shift register, respectively, to generate multiplexed chips. The multiplexed chips include alternating sets of shifted-in-phase chips and shifted-quadrature-phase chips. A controller generates a POWERDOWN signal when the multiplexed chips from a received-spread-spectrum signal are unlikely to have a particular-chip sequence. The controller generates an ACTIVATION signal when the multiplexed chips are likely to have the particular-chip sequence present. An adder tree generates a CORRELATION signal when the multiplexed chips have the particular-chip sequence and match or correlate with the settings of the adder tree.

Abstract: A hierarchical arrangement of security devices for securing a protected network through a plurality of security devices having security rules of descending strictness. The system includes a first security device between two networks, and a second security device coupled to the first security device. A frame is processed by the first security device if the first security device's security policy allows processing. If there is insufficient information for the first security device, the first security device passes the frame to the second security device for processing. Additional security devices may be added in a hierarchical chain as necessary or desired. Passing-off may also be prevented to provide multi-level security within a protected network.

Abstract: A vibratory drive for use with a screening machine for draining and/or sizing of grain solids, the drive having two eccentric shafts which are driven synchronously and in counterrotation and which have different unbalanced masses 7, 8. The eccentric shafts are arranged as near as possible to the mass center 16 of the screening machine. The angle of the mass forces of the unbalanced masses 7, 8 of the eccentric shafts includes an angle of 60.degree. to 90.degree., preferably 90.degree., between the main direction of oscillation 18, i.e., the long axis 19 of the ellipse oscillation as a resultant of the centrifugal forces, and the zero line 17, i.e., the tie line of the eccentric shafts.

Abstract: A system and method for controlling unauthorized access to software distributed to a user by a vendor in which a verification key is generated by a product key generator and either embedded in the software prior to distribution or packaged with the software as a self-installing package. The verification key includes a private signing key and a public verification key. The combination of the software and the verification key create distributable software which is distributed to a user. The user installs the software on a user computer system as protected software. To obtain a user key, the user inputs user identifying information which is sent to a user key generator. The user key generator converts the user identifying information to a numeric representation and then generates, by signing the numeric representation with the private signing key, a user key, which is returned to the user.

Abstract: A method for encryption wide-bandwidth video, using a first processor for encrypting the video and a second processor for decrypting the video. Data is taken in blocks. A block of data is scrambled to generate scrambled data, then partitioned into a first portion and a second portion. A global key is generated at the first processor and the second processor, using public key technology. At the first processor, the global key is exclusively-ORed with the first portion, thereby generating a encrypted second portion. At the first processor, a random number is generated from the first portion and exclusively-ORed with the second portion to generate an encrypted second portion. At the second processor, the global key is exclusively-ORed with the encrypted first portion. At the second processor, the random number is recovered from the decrypted first portion and exclusively-ORed with the encrypted second portion to decrypt it. The scrambled data are descrambled, thereby recovering the data.

Abstract: A method and system for displaying a function in two dimensions where the function is made up of numerous independent variables and at least one dependent variable. A new independent variable value can be defined having values which correspond to the multiple dependent variables. The variable values are read into a computer and the independent variables are then ranked by the user from fastest- to slowest-running variable. Each dependent variable corresponding to the new independent variable is plotted along the Y-axis. The independent variable values are plotted along the X-axis in a hierarchical manner. The hierarchical manner involves a nesting of fastest-running variables within slower-running variables. Rectangles are then drawn to correspond to each variable value. Each rectangle horizontally encloses the faster-running variables associated with it.