Method for correcting Doppler frequency difference of high speed moving body

Abstract

The invention provides a high-speed moving body Doppler frequency difference correction method which comprises downward frequency difference correction and upward frequency difference correction; wherein, the downward frequency difference correction corrects the Doppler frequency difference of a carrier frequency signal by superposing a pilot signal generated by a standard VCO in a downward carrier frequency signal and detecting the frequency difference of the pilot signal at a mobile terminal; by detecting the frequency difference of the downward pilot signal and pre-superposing the Doppler frequency difference in the carrier frequency signal at the mobile terminal, the upward frequency difference correction corrects an upward signal g received at a fixed terminal due to Doppler frequency shift. The whole correction method evades the changes of an arrival angle and the speed of the mobile terminal, the correction is accurate and timely, and the communication quality is guaranteed to be stable and reliable.

Description

technical field [0001] The invention relates to a mobile communication transmission method, in particular to a Doppler frequency difference correction method for a high-speed moving body. Background technique [0002] At present, the speed of high-speed trains has reached more than 300 km / h, and even reached more than 500 km / h; the speed of aircraft has reached 800 to 1000 km / h. The device is not functioning properly. The impact of the Doppler effect on soft handover is that it will affect the measurement performance of the same frequency adjacent cell of the terminal. As the frequency offset increases, the measurement performance of the user terminal also decreases. When the frequency offset exceeds a certain threshold, The soft handoff process will not be triggered. For the mobile communication users in the high-speed mobile body, the signal frequency they receive is f=fo±△f (fo is the base station frequency, △f is the frequency difference, where ), because the high-sp...

AI Technical Summary

Problems solved by technology

[0002] At present, the speed of high-speed trains has reached more than 300 km / h, and even reached more than 500 km / h; the speed of aircraft has reached 800 to 1000 km / h. The device is not working properly

The impact of the Doppler effect on soft handover is that it will affect the measurement performance of the same frequency adjacent cell of the terminal. As the frequency offset increases, the measurement performance of the user terminal also decreases. When the frequency offset exceeds a certain threshold, The soft handover process will not be triggered

For the mobile communication users in the high-speed mobile body, the signal frequency they receive is f=fo±△f (fo is the base station frequency, △f is the frequency difference, where ), because the high-speed moving body is moving at a high speed, the angle of arrival of the received signal The change is random and uncertain, and it is difficult to accurately calibrate the frequency due to the time lag in calculating the compensation error. Therefore, the frequency error correction method of this high-speed moving body has large errors and poor communication quality

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