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

Large Doppler wireless communication time-frequency synchronization method based on OFDM

A time-frequency synchronization, wireless communication technology, applied in wireless communication, synchronization device, multi-frequency code system, etc., can solve the problems of fast satellite moving speed, overshoot, multi-path channel fading, etc., to solve real-time changes and realize flexible application , to satisfy the effect of correct demodulation

Active Publication Date: 2020-09-18
NO 54 INST OF CHINA ELECTRONICS SCI & TECH GRP
View PDF7 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Especially in the LEO low-orbit satellite communication scenario, the satellite moves fast, there is a large-scale Doppler frequency shift between the satellite and the ground, and multipath channel fading, and the general Doppler frequency shift is much larger than the subcarrier spacing of the OFDM system , which exceeds the current frequency offset estimation capability of the terrestrial 5G standard, which makes the carrier and symbol synchronization at the two ends of the satellite and the ground face a big problem
Therefore, time-frequency synchronization is the primary problem to be solved in the wireless communication system under the condition of Doppler frequency shift, especially the satellite communication system integrated with 5G, which restricts the effective application of 5G OFDM technology in satellite communication

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
  • Large Doppler wireless communication time-frequency synchronization method based on OFDM
  • Large Doppler wireless communication time-frequency synchronization method based on OFDM
  • Large Doppler wireless communication time-frequency synchronization method based on OFDM

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0034] The present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments.

[0035] A method for time-frequency synchronization of Doppler wireless communication based on OFDM, applied to a receiving end of a wireless communication system, wherein the receiving end stores the same primary synchronization symbol and data symbol frequency domain pilot as the sending end, comprising the following steps :

[0036] (1) Receive OFDM transmission signals including preamble symbols, primary synchronization symbols and data symbols, use preamble symbols to perform sliding correlation calculations, detect correlation peaks, and perform rough symbol timing synchronization;

[0037] (2) Use the preamble symbol to perform rough estimation of the Doppler frequency offset, and realize the joint estimation of the integer multiple frequency offset and the fractional multiple frequency offset;

[0038] (3) Utilize the estimation result...

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 a large Doppler wireless communication time-frequency synchronization method based on OFDM, and belongs to the technical field of wireless communication. The method comprises the following steps: realizing symbol coarse timing synchronization by utilizing a preamble symbol; realizing large Doppler frequency offset coarse estimation by utilizing the preamble symbol; carryingout frequency offset preliminary compensation correction on the symbol by using the frequency offset estimation value; performing correlation operation on the PSS symbol subjected to frequency offsetpreliminary compensation and a locally known PSS symbol; realizing accurate timing synchronization of the symbol, performing FFT operation on the data symbol, realizing signal time-frequency domain conversion, and realizing residual frequency offset estimation and real-time compensation through a first-order filtering frequency-locked loop by utilizing a frequency domain pilot frequency in the received data symbol and a locally known pilot frequency. According to the invention, time and frequency synchronization of a wireless communication system in an OFDM-based large Doppler scene can be realized under the condition that a user terminal and a gateway station have no ephemeris, and the synchronous demodulation requirements of a future broadband high-throughput satellite under large Doppler and multipath conditions are met.

Description

technical field [0001] The invention relates to the technical field of wireless communication, in particular to an OFDM-based Doppler wireless communication time-frequency synchronization method. Background technique [0002] Orthogonal Frequency Division Multiplexing (OFDM) technology is widely used in terrestrial wireless cellular communication systems due to its strong anti-multipath ability and high spectrum efficiency, especially the NR Release15 of the fifth generation mobile communication system (5G). Non-Standalone Networking (NSA) and Release 16 Standalone Networking (SA) standards still use OFDM waveforms as the core waveforms for physical layer transmission. However, the receiving end of OFDM technology is sensitive to carrier frequency deviation (CFO) and symbol timing deviation that cause inter-subcarrier interference (ICI), which restricts the implementation of OFDM technology in wireless communication systems under large dynamic Doppler conditions, especially ...

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
IPC IPC(8): H04L27/26H04W56/00
CPCH04L27/2663H04L27/2665H04W56/005
Inventor 刘允宋瑞良宋志群卢宁宁李捷
Owner NO 54 INST OF CHINA ELECTRONICS SCI & TECH GRP
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