Method and device for pre-calibrating frequency deviation

Abstract

A method and device for frequency deviation pre -correction are provided. The method includes: estimating an uplink frequency deviation value of a terminal, and obtaining a historic value of the uplink frequency deviation pre -correction that has been used for the frequency deviation pre -correction of the terminal; according to the historic value of the uplink frequency deviation pre-correction, determining a current value of the uplink frequency deviation pre-correction of the terminal, the current value of the uplink frequency deviation pre-correction being closer to the uplink frequency deviation value than the historic value of the uplink frequency deviation pre-correction; by using the current value of the uplink frequency deviation pre-correction, pre -correcting the frequency deviation of the terminal, thereby the signal detection performance of the terminal can be effectively improved.

Description

technical field [0001] The present invention relates to the field of wireless communication, in particular to a frequency offset pre-calibration method and equipment. Background technique [0002] In a mobile communication system, a base station uses a frequency fc of a fixed frequency point to transmit and receive multi-user signals, and a terminal tracks the frequency of received signals through an automatic frequency control (Automatic Frequency Control, AFC) technology. In a high-speed mobile environment, the base station sends signals at a frequency of fc, and the terminal receives a signal at a frequency of fc+Δf through the channel, where Δf is the Doppler frequency shift. After a period of time, the transceiver frequency of the terminal is stable at the received signal frequency of fc+Δf nearby. In this way, the frequency of the signal sent by the terminal is fc+Δf, the frequency of the signal received by the base station after passing through the uplink channel is ...

AI Technical Summary

Problems solved by technology

[0008] The existing frequency offset pre-calibration scheme cannot be applied to the broadcast channel. Therefore, when the Doppler frequency shift of the channel is fd, the terminal frequency locks to fc+fd. At this time, the frequency offset estimated by the base station side is 2fd. If the service starts at this time connection, and perform frequency offset pre-calibration processing on the traffic channel, then the frequency offset sent by the traffic channel is fc-2fd, the frequency of the terminal receiving the signal after the channel is fc-fd, and the terminal local oscillator is fc+fd, at this time the terminal solution There will be a 2fd frequency offset in the tuned signal. In the TD-SCDMA system, when the vehicle speed is 400Km / h, the value is about 1500Hz, which will seriously deteriorate the signal detection performance of the terminal

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