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Frequency calibration method and device

A frequency calibration and variance technology, applied in the field of frequency calibration methods and devices, can solve the problems of increased processing delay, difficulty in setting the threshold of peak validity, uncertain delay, etc.

Active Publication Date: 2014-07-16
DATANG MOBILE COMM EQUIP CO LTD
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  • Summary
  • Abstract
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  • Claims
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AI Technical Summary

Problems solved by technology

In this way, on the one hand, it is difficult to set the threshold when judging the validity of the peak value. On the other hand, since it is necessary to search for a large frequency offset according to a certain step size, the processing delay will also be increased and there are factors of delay uncertainty.
[0007] It can be seen that the frequency offset estimation algorithm in the AFC calibration of the existing comprehensive tester under the modulation signal mode has a contradiction between a large frequency offset estimation range and precise synchronization. In order to solve this contradiction, a large frequency offset search is generally carried out at a certain step size It is judged as valid until the correlation peak value at the time of fine synchronization meets a certain threshold. On the one hand, it is actually difficult to set the threshold of peak validity, and the large frequency offset search will also increase the processing delay, and there are factors of delay uncertainty.

Method used

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  • Frequency calibration method and device

Examples

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Embodiment 1

[0121] This embodiment is the frequency calibration during AFC calibration in the modulation signal mode in the WCDMA system.

[0122] Such as image 3 As shown, the frequency calibration method includes:

[0123] Step S301, host computer configuration β c =15 and β d = 0, so that the terminal only transmits DPCCH signals, but not DPDCH signals. The purpose of this configuration is to obtain the modulated signals of the standard QPSK constellation diagram, so as to facilitate the removal of modulation information, thereby performing frequency offset estimation.

[0124] Step S302, rising edge detection:

[0125] Assuming that the comprehensive tester receives a wireless frame of data r=[r(0), r(1),...,r(N-1)], N=OSR*N c *N slot , where OSR is the oversampling rate, N c =2560 is the number of chips in one time slot of the DPCCH channel, N slot =15 is the time slot number of input data;

[0126] Compute the power value for a sliding window of received signal samples: ...

Embodiment 2

[0189] This embodiment is in the TD-SCDMA system, the frequency offset estimation during the AFC calibration under the 12.2kbps modulation signal mode, and it is assumed that the timing synchronization has been performed before the frequency offset estimation, and the timing synchronization process is the same as the timing synchronization process in the first embodiment same.

[0190] Such as Figure 4 As shown, the frequency calibration method includes:

[0191] Step S401, the host computer configures the terminal to send the QPSK-modulated DPCH signal in the allocated uplink time slot. In addition, the host computer also needs to configure the scrambling code number, the basic Midamble code (intermediate code) number, and the scrambling code number (according to the protocol scrambling code) sent by the terminal. The code number is equal to the basic midamble number), the midamble offset, and the spreading factor and spreading code.

[0192] Step S402, rising edge detecti...

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Abstract

The invention relates to the communication technology and discloses a frequency calibration method and device. A terminal sends a PSK modulation signal, after the PSK modulation signal is received, a section of data long enough behind the position of the rising edge is intercepted, a group of data are determined for rough frequency offset estimation and rough frequency offset compensation, wherein variance of the amplitude of the data is the smallest, then the precise time slot starting position is determined, data of a time slot are intercepted again, and a fine frequency offset deviant is determined according to the data, so that the accurate frequency offset is obtained, and accuracy of frequency calibration can be improved by conducting frequency calibration according to the frequency offset. Meanwhile, due to the fact that rough frequency offset estimation and rough frequency offset compensation are first conducted, then the precise time slot starting position is determined, and the data are intercepted for fine frequency offset compensation, efficiency for determining the frequency offset deviant is improved, and efficiency of frequency calibration is further improved.

Description

technical field [0001] The present invention relates to communication technology, in particular to a frequency calibration method and device. Background technique [0002] Before the terminal is connected to the network, it needs to perform radio frequency conformance test. Fast frequency calibration of the terminal has become one of the necessary functions of the test equipment. The frequency error of the terminal in the calibration stage is characterized by a large frequency error range, which can reach tens of kHz. Therefore, higher requirements are placed on the test equipment. [0003] With the rapid development of mobile communication systems, terminals supporting multiple standards have also been rapidly developed. At present, terminal manufacturers have developed related products supporting multiple standards such as GSM, WCDMA, TD-SCDMA, and LTE. Before these terminal products enter the network, they need to be tested for conformance, and the radio frequency confor...

Claims

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Application Information

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IPC IPC(8): H04L27/26
Inventor 李向宁徐红艳马艳君
Owner DATANG MOBILE COMM EQUIP CO LTD
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