34results about How to "Eliminate frequency offset" patented technology

The invention relates to a radio-frequency circuit comprising: - a control unit; and - a phase-locked loop; wherein the control unit is arranged to determine an offset between an actual value of a reference frequency at the input to the loop on the basis of a measurement of the signal output from the filter of the loop, and a theoretical value of said frequency known to the control unit, via a relation known to the control unit, and to control a correction of said offset.

A method, device and system for calibrating an equipment clock, a self-calibrating method and equipment, the equipment includes a TSXO and a GPS module, and the GPS module includes a signal receiver; the method for calibrating the equipment clock includes: through the GPS module eliminating the self-contained frequency offset of the TSXO; and calibrating the temperature drift of the TSXO. Through this method, a low-cost and high-precision clock solution with a built-in positioning function can be provided for ubiquitous connected devices.

The invention relates to an analog-digital hybrid high-speed signal time measurement system based on clock data recovery, and belongs to the field of communication signal processing. The system comprises a laser receiving module, a clock data recovery module, a clock management module, a frequency mixing module, a low-pass filtering module, a sampling module, a carrier tracking module, a signal capturing module and a ranging velocity measurement information resolving module. Through the system disclosed by the invention, the dependency on the high-speed ADC by a signal processing algorithm canbe reduced, the requirement on the ADC sampling rate is reduced, the data communication rate is further improved, the information utilization rate on the communication / ranging frame can be increased,and the ranging velocity measurement precision is improved.

The present invention relates to a method for eliminating frequency offset in a communication system by using sync header predistortion, which comprises the following steps: (1) the terminal eliminates the frequency offset of the data signal after the sync header according to the received sync header; (2) Observing the constellation diagram of the data signal obtained in step (1) and the receiving signal-to-noise ratio of the data signal output after calculation by the terminal, determining the constellation diagram rotation angle of the data signal after the frequency offset is removed; (3) The constellation diagram rotation angle of the data signal after the frequency offset is eliminated is used as the sync header pre-distortion value, and the sync header pre-distortion value is configured through the network management; (4) the base station performs pre-distortion processing according to the sync header pre-distortion value configured by the network management And send the downlink signal after the pre-distortion processing; (5) The terminal eliminates the frequency offset of the data signal after the sync header according to the sync header after the pre-distortion processing. With the help of the method, the frequency offset in the communication system can be eliminated accurately and effectively, and the normal operation of the system is guaranteed.