Uplink carrier frequency offset estimation and compensation method for low-earth-orbit satellite multi-carrier communication system

Abstract

The invention designs an uplink carrier frequency offset estimation and compensation method for a low-earth-orbit satellite multi-carrier communication system, and belongs to the field of wireless communication. The uplink refers to a transmission link which is transmitted by a user terminal, forwarded by a satellite and received by a gateway station. The method specifically comprises the following steps: (1) a user terminal calculates an uplink pre-compensation carrier frequency offset value according to a downlink carrier frequency offset estimation value, and pre-compensates an uplink transmission signal; (2) the gateway station estimates Doppler carrier frequency offset of uplink and downlink feed links based on ephemeris, calculates a feed link carrier frequency offset compensation value, and performs first compensation on uplink received signals; and (3) the gateway station estimates the uplink residual carrier frequency offset by using the uplink synchronization or reference signal, and performs secondary compensation on the uplink received signal. By utilizing the method and the system, the uplink carrier frequency offset can be accurately estimated and compensated under the condition that the user terminal has no ephemeris and only the gateway station has ephemeris, so that the demodulation requirement of multi-carrier communication under the large Doppler carrier frequency offset of a low-earth-orbit satellite is met.

Description

technical field [0001] The invention belongs to the field of wireless communication, and in particular relates to a method for estimating and compensating frequency offset of an uplink carrier in low-orbit satellite multi-carrier communication. [0002] technical background [0003] With the development of communication requirements, in order to meet the high-speed data transmission in remote areas without base station coverage, in the future mobile communication, it has become an important issue to achieve communication coverage for remote areas through low-orbit satellites. A typical low-orbit satellite communication system such as figure 1 As shown, the system components include: (1) gateway station, (2) satellite, (3) user terminal. (2) The satellite is only responsible for transparent forwarding, that is, it only performs frequency shift forwarding processing on the received signal, and does not perform signal modulation and demodulation. The link between the gateway s...

AI Technical Summary

Problems solved by technology

[0010] In order to solve the problem that the uplink carrier frequency offset estimation and compensation of the low-orbit satellite multi-carrier communication system has large compensation errors and the user terminal depends on the ephemeris, the present invention proposes a low-orbit satellite multi-carrier communication system uplink carrier frequency Partial Estimation and Compensation Method

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