Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

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

A multi-carrier communication and sampling frequency offset technology, applied in multi-carrier systems, modulated carrier systems, multi-frequency code systems, etc., can solve problems such as performance loss, achieve reduced range, reduced estimation complexity, and high demodulation Effect of SNR Range

Active Publication Date: 2020-05-08
上海众睿通信科技有限公司
View PDF7 Cites 8 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] In order to solve the problem of low-orbit satellite multi-carrier communication system, sampling frequency offset brings performance loss to reception, the present invention proposes a method for estimating and compensating uplink sampling frequency offset of low-orbit satellite multi-carrier communication system

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Uplink sampling frequency offset estimation and compensation method for low-earth-orbit satellite multi-carrier communication system
  • Uplink sampling frequency offset estimation and compensation method for low-earth-orbit satellite multi-carrier communication system
  • Uplink sampling frequency offset estimation and compensation method for low-earth-orbit satellite multi-carrier communication system

Examples

Experimental program
Comparison scheme
Effect test

specific example

[0038] refer to image 3, the specific example of the uplink sampling frequency offset estimation and compensation method is as follows:

[0039] Step 1: The user terminal estimates the uplink pre-compensated sampling frequency offset according to the downlink sampling frequency offset estimation result, and performs the first compensation for the uplink signal transmitted by the user terminal according to the calculated uplink pre-compensated sampling frequency offset estimation value; specifically In this way, the estimation result of the downlink sampling frequency offset of the user terminal is Downlink sampling frequency is f s,downlink , the uplink sampling frequency is f s,uplink . Then the uplink precompensation sampling frequency offset estimation value f pre,uplink for:

[0040]

[0041] Step 2: The user terminal uses the uplink reference signal to estimate the frequency offset of the uplink residual sampling, and uses the estimated value of the uplink resid...

Embodiment 1

[0056] Assume that the satellite flight altitude is 1175km, and the satellite flight speed is 7.2km / s. The elevation angle of the gateway station to the satellite is 5°, the maximum elevation angle between the public reference point of the user link and the satellite is 30°, the width of the satellite beam is 3°, and the uplink and downlink sampling frequency f s Both are 491.52MHz. Considering that the terminal is located at the center of the beam coverage (cell reference point), the Doppler sampling frequency offset calculation formula is It can be calculated that in the terminal-satellite-gateway link, the uplink and downlink Doppler sampling frequency offsets are both 14.5 kHz. Assuming that the sampling crystal precision of the terminal and the gateway station are both 100ppb, in the worst case, the total downlink sampling frequency deviation is about 14.4kHz, and the uplink total sampling frequency deviation is about 14.6kHz.

[0057] Assuming that the downlink user t...

Embodiment 2

[0059] Assume that the Gaussian white noise channel of the terminal-satellite-gateway station uplink channel adopts 8PSK modulation, the code rate is 0.891, and the receiving signal-to-noise ratio is 10dB. Assuming that the uplink sampling frequency offset is 5000 Hz, without pre-compensation in step 1, the sampling frequency offset is estimated only by segment correlation of the reference signal in step 2. Simulation results such as Figure 5 As shown, the estimated root mean square error obtained through simulation is 32.4 Hz. It can be seen that this method has high accuracy in estimating the uplink residual sampling frequency offset. As shown in the simulation results, in this simulation scenario, the sampling frequency offset will cause a performance loss of about 2.6dB to the system, but after being estimated and compensated by the algorithm of the present invention, the link performance is compared with the ideal link without sampling frequency offset The performance l...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses an uplink sampling frequency offset estimation and compensation method for a low-orbit satellite multi-carrier communication system. An uplink refers to a transmission link which is transmitted by a user terminal, forwarded by a satellite and received by a gateway station. The specific method comprises the following steps: a user terminal calculates an uplink pre-compensation sampling frequency offset value according to a downlink sampling frequency offset estimation value, and pre-compensates an uplink transmitting signal by adjusting a crystal oscillator or using a resampling digital filter; the gateway station estimates uplink residual sampling frequency offset by using the uplink reference signal and a segmentation correlation algorithm, and compensates an uplink received signal in a frequency domain. By utilizing the method provided by the invention, large-range, high-precision and low-complexity estimation and compensation of the uplink sampling frequencyoffset can be realized so as to meet the demodulation requirement of multicarrier communication under the large Doppler sampling frequency offset of a low-orbit satellite.

Description

technical field [0001] The invention belongs to the field of wireless communication, and in particular relates to an uplink sampling frequency offset estimation and compensation method 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 station a...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): H04L27/38H04L27/26H04L27/00
CPCH04L27/3872H04L27/2657H04L27/0014H04L2027/0026
Inventor 张毅刘田马松袁田夏彬徐元浩
Owner 上海众睿通信科技有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com