37results about How to "Synchronization is stable" patented technology

Disclosed is a system and a training sequence setting method for performing frame synchronization in a wireless communication system. A received signal is affected by a frequency offset due to an oscillator mismatch between the transmitter and the receiver, which is one of the main causes of performance degradation of frame synchronization. In a prior Constant Amplitude Zero Auto-Correlation (CAZAC) sequence, the larger the frequency offset becomes, the more conspicuously the performance degradation of the frame synchronization occurs. The proposed training is designed to maintain a prior CAZAC property during a differential detection so as to perform a differential detection-based frame synchronization sequence insensitive to the frequency offset. As a result of performance verification, the proposed training sequence indicates that its performance of the frame synchronization is irrespective of the frequency offset, and has a better performance than the prior CAZAC sequence and random sequence.

The invention discloses a crawler type length counting device comprising two synchronous belt mechanisms. The two synchronous belt mechanisms arranged in an up-down mode are used for clamping a measured object, wherein the center distances are equal; portions, between the two pairs of front and back synchronous belt wheels, of clamping sides of the synchronous belts of the upper synchronous belt mechanism and the lower synchronous belt mechanism serve as clamping and contact segments; and pressure exerting mechanisms that are capable of exerting positive pressures on the clamping and contact segments towards the direction of the measured object are arranged at the inner sides of the upper synchronous belt mechanism and the lower synchronous belt mechanism. According to the invention, the pressure exerting mechanisms are used for exerting pressures on the clamping and contact segments of the synchronous belts, so that the clamping and contact segments can clamp the measured object all the time under the pressure effect. Therefore, the slipping phenomenon can be avoided and thus the stable synchronization performance can be realized during the whole metering process, thereby improving the length counting precision. Meanwhile, the running of the whole mechanism becomes smooth and stable, thereby substantially reducing the influence on the length counting precision by shaking.

A signal generator can control phase relationship between output signals of the channels without stopping clocks provided to the channels to enable the circuit operation fast. First and second channels 20 and 22 have signal generation blocks 10 and 12 that have clock phase shift circuits 26 and 28, memories, parallel to serial converters and DACs respectively. A phase comparator 24 compares data reading clocks from the signal generation blocks 10 and 12 to produce a phase difference signal wherein the data reading clocks are used to read waveform data from the memories within the signal generation blocks 10 and 12. A CPU controls the clock phase shift circuits 26 and 28 according to the phase difference signal to shift phases of the clocks provided to the signal generation blocks 10 and 12 and then makes phase relationship between the output signals of the first and second channels 20 and 22 as desired.

The invention relates to a vacuum presser which comprises a distributor, a pressing system, an unloading device, a vacuum system, a driving system, two pieces of filter cloth and a frame, wherein the pressing system is arranged on the top and the middle lower part on the right side of the frame; the distributor is arranged at one end of the top of the pressing system; the unloading device is arranged on one side, which is opposite to the distributor, of the pressing system; the vacuum system is arranged on the left lower part of the frame; the driving system is arranged on the frame below the unloading device; the two pieces of filter cloth are respectively wound into two closed loops; the two pieces of filter cloth are meshed in the right middle part of the pressing system. The traditional pressing dehydration and vacuum negative pressure dehydration are perfectly combined together, and materials can be well treated, so that the equipment is wide in application range, and the dehydration efficiency in unit time is greatly improved.