Method and equipment for presetting downlink frequency offset

Abstract

The invention provides a method and equipment for presetting downlink frequency offset. The method comprises the following steps: determining the uplink frequency offset receiving each uplink signal when the uplink signal transmitted on a public channel by each terminal of a coverage area is received; determining downlink frequency offset when an antenna of a base station transmits a downlink signal on the public channel to each terminal, according to the uplink frequency offset; and compensating the downlink frequency when the antenna of the base station transmits the downlink signal on the public channel according to the downlink frequency offset. According to the method and the equipment, the frequency offset when the downlink signal transmitted on the public channel reaches the terminal.

Description

technical field [0001] The present invention relates to communication technology, in particular to a downlink frequency offset preset method and equipment. Background technique [0002] When there is relative motion between the transmitting source and the receiving body, the frequency at which the receiving body receives the signal sent by the transmitting source is different from the frequency at which the transmitting source transmits the signal. This phenomenon is called the Doppler effect, and the receiving frequency and the transmitting frequency The difference is called Doppler shift. [0003] On a high-speed train, the terminal is in a high-speed motion state when receiving or sending signals, so that the base station is in a high-speed motion state relative to the terminal. When the terminal and the base station are in high-speed motion, the received signal will produce obvious Doppler frequency shift. At present, high-speed vehicles with a speed of 300-350km / h hav...

AI Technical Summary

Problems solved by technology

[0004] When there is a Doppler shift in the downlink signal on the common channel of the base station, it will have a serious impact on the communication performance

For example, a terminal in the idle state cannot read the broadcast information of the Primary Common Control Physical Channel (PCCPCH for short); the demodulation performance of the Paging Indicator Channel (PICH for short) deteriorates, and the paging The terminal in the idle state cannot be called, which reduces the access success rate; the demodulation performance of the Fast Physical Access Channel (FPACH channel for short) and the Secondary Common Control Physical Channel (SCCPCH channel for short) deteriorates. Poor, affecting the establishment of Radio Resource Control (RRC) connections, making it difficult for terminals to access

However, there is currently no feasible frequency offset compensation scheme for downlink signals on common channels

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