Method and equipment for processing frequency offset

Abstract

The invention discloses a method and equipment for processing frequency offset. The method comprises the following steps that: network side equipment estimates the frequency offset of a terminal; and the network side equipment informs the terminal of the frequency offset, and the terminal adjusts local oscillation according to the frequency offset. The method and the equipment have the advantages of greatly lowering requirements on the terminal, remarkably enhancing the adaptability of the terminal to a high-speed network environment, simplifying implementation scheme and particularly allowing the terminal to rapidly and reliably track and lock a target cell during high-speed switching.

Description

technical field [0001] The present invention relates to wireless communication technology, in particular to a frequency offset processing method and equipment. Background technique [0002] When the UE moves relative to the base station, a Doppler frequency shift will occur. The size of the Doppler frequency shift is related to the speed of the UE, the angle between the direction of the UE’s motion and the direction of the incident wave. The Doppler frequency shift f d is defined as follows: [0003] f d = v c × f h × cos ( θ ) [0004] v is the moving speed of the UE, c is the propagation speed of light in free space, θ is the angle between the moving direction of the UE and the incident wave, f h is the carrier frequency. [0005] The AFC (Automatic Frequency Control, automatic frequency control)...

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Problems solved by technology

[0007] With the development of high-speed railway and maglev railway, the moving speed of UE in mobile communication will be greatly improved, and the highest speed can reach 300-400Km / h. For example, the train moving speed of Shanghai maglev railway has reached 431km / hour. In such a speed environment, a large Doppler frequency shift will be introduced; this also leads to the following shortcomings in the existing technology: if the UE stays in the same cell all the time, its AFC scheme can still track normally, but when the UE is in the When a high-speed handover occurs between two adjacent cells, due to the change of the direction of the incident wave, the Doppler frequency shift will jump from the negative maximum value to the positive maximum value. At this time, it takes a long time to adopt the AFC control scheme In order to enter a stable state, this will deteriorate the performance of the UE, especially for services that are sensitive to delay requirements, which will easily lead to call drop

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