摘要:
A transmitter is provided which simultaneously transmits waveforms such as with different data rates. These transmissions are modulated (e.g. phase modulated) onto quadrature channels of a common carrier, and are then combined. The resulting composite modulated waveform is upconverted to RF, power amplified, split and routed to separate ports for transmission. The transmitted signals are then received, downconverted and demodulated to produce the original signals.
摘要:
A set of independent pseudonoise (PN) component codes greater than two are combined in a manner which produces one or more I and Q uncorrelated orthogonal pairs of resulting combined PN sequences. At least two of the component codes in a resulting combined PN sequence are combined in a manner which produces an overall imbalance of ones and zeros in the binary expression of the resulting combined PN sequence so that the resulting composite code has a partial correlation with a predetermined one of the PN component codes. In the preferred embodiment, three component codes are combined to produce uncorrelated orthogonal pairs of composite codes wherein at least one of the pairs of composite codes is produced to have a partial correlation with one or more of the component codes.
摘要:
A timing correction system for fast PN acquisition is provided. The system includes a signal sampler for testing any incoming signal and a real-time clocker coupled to the signal sampler. A parallel correlator is coupled to the real-time clocker for searching for a PN sequence and a burst detector is coupled to the parallel correlator. A chip timing corrector is coupled to the burst detector and a processor is coupled to the chip timing corrector for determining signal timing.
摘要:
A novel digital variable rate clock synthesizer is provided with a novel fractional-N digital phase locked loop. The all digital phase locked loop employs a digital input signal to a phase comparator which has a second input coupled to a digital control oscillator through a divide by N or a divide N+1 circuit. The digital output of the phase comparator is coupled to an error accumulating circuit which has a phase correction input signal from a fractional register and an associated accumulator. The output from the error accumulator is coupled to a pair of detectors for generating phase and frequency error detection signals which are digitally coupled to the control input of the digital control oscillator to provide a variable frequency output selected by the value of N and N+1.
摘要:
A method and system is disclosed for generating and detecting variable sequence PN codes. PN-Code sequence changes based on varying interceptor threat levels are generated at a rate fast enough to avoid exploitation while maintaining a reasonable correlation search window. The PN code sequence is phase shifted by N-chips based on the severity of the threat environment. A synchronized receiver demodulates the PN encoded signal by correlating over every possible phase of the PN code sequence. The receiver includes first and second correlators and threshold detectors adapted to detect PN signals with varying PN code sequence changes.
摘要:
A plastic pipe butt fusion machine has a base, a clamp on the base for securing a first length of plastic pipe, a second clamp mounted on the base for securing a second length of plastic pipe to be fusion welded to the first in axial end-to-end alignment, the second clamp being moveable relative to the base, a spring positioned between the second clamp and the base so that when the spring is tension loaded the second clamp is urged in the direction toward the first clamp to thereby resiliently urge the plastic pipes held by the first and second clamps into axial abutted relationship during fusion.
摘要:
An apparatus for tapping an opening into an existing pipeline that is under internal pressure including an elongated tapping machine body having means on one end for attachment to a pipeline, a boring bar having a rotatable feed screw therein by which the boring bar is axially positioned, and a pressure responsive valve actuated by differential pressure between the interior of a pipeline and the interior of the tapping machine body to control hydraulic pressure inside the tapping machine body to thereby counterbalance the hydraulic force applied to the boring bar.
摘要:
Well tools which must be rotated after landing are equipped with an antifriction bearing in such fashion that the tool is supported through the bearing initially and then supported via solid metal-to-metal contact which bypasses the bearing.
摘要:
An explosive cutting device comprising an upper and lower member, each having a charge retaining area and a standoff area, a linear shaped explosive charge contained within each charge retaining area of the upper and lower member, a pair of anti-jet distortion members located on both the upper and lower member thereby defining an opening between the upper and lower member into which a target member to be severed is placed, a fastening means for securing the upper member to the lower member, and means for detonating the linear shaped explosive charge within the upper and lower member.
摘要:
Doors, especially exterior doors are installed in a building long before the construction is finished. Many doors utilize multipoint lock assemblies or mortise locks, these doors typically have expensive hardware that needs to be installed in order to open, use or lock these doors. Continued use and handling of this hardware results in damage to the same. For this reason, the inventive concept includes low cost handles that can easily be installed and can be used over and over again. The low cost hardware consists of low cost handle that are passed through existing lock mechanisms within the door. The low cost handles include a grommet on one side of the door that will be inserted into an existing opening in the door as sealant against dirt and debris. Also included on the handle is a compressible tube on another side of the handle that acts to reduce any play within the temporary mechanism. The handles are so constructed that the doors can be operated from both sides of the doors, one side only, or none at all.