Frequency Offset Estimation in OFDM Systems
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Solution Overview
Problem
Current Orthogonal Frequency Division Multiplexing (OFDM) technologies face challenges in accurately estimating large frequency offsets with high precision while maintaining low implementation complexity.
Innovation Solution
A method involving initial channel estimation using Sounding Reference Signals (SRS) or Preamble codes, determining frequency offset ranges, and calculating dual pilot frequency offset values based on phase differences to achieve precise frequency offset estimation within defined ranges, reducing complexity through smoothing and filtering processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional frequency offset estimation methods are used for large frequency offsets, then the precision of frequency offset estimation is improved, but the complexity of implementation is increased
Solution Approach 1:
The frequency offset estimation process is segmented into two distinct stages: a rough estimation stage using SRS/Preamble codes to obtain an initial frequency offset value, and a fine estimation stage using dual pilots to obtain a refined frequency offset value. This segmentation allows each stage to focus on specific requirements (coarse coverage vs. fine precision) without unnecessary complexity from the other stage, thereby achieving high precision for large frequency offsets while maintaining manageable implementation complexity.
2Measurement precision
If high precision frequency offset estimation is achieved for large offsets, then estimation accuracy is improved, but the complexity of the estimation process is increased
Solution Approach 1:
The method performs preliminary rough frequency offset estimation using SRS or Preamble codes before conducting fine frequency offset estimation using dual pilots. This preliminary action establishes an initial frequency offset value that narrows down the search range for the subsequent fine estimation process, thereby achieving high accuracy for large frequency offsets while avoiding the complexity of directly performing fine estimation over the entire possible frequency offset range.
Data Source
AI summary
The present invention provides a method, device and storage medium for frequency offset estimate, and the method for frequency offset estimate comprises: performing initial channel estimate by receiving an Sounding Reference Signal (SRS) or a Preamble code transmitted by a User Equipment (UE) to obtain a first frequency offset estimate value of a current sub-frame of the UE (S101); determining a frequency offset range in which the first frequency offset estimate value is located, and obtaining an initial frequency offset value corresponding to the first frequency offset estimate value according to the preset correspondence between the range of the frequency offset and the initial frequency offset value (S102); determining a phase difference of adjacent pilot positions based on a received pilot sequence included in the current sub-frame, and obtaining a dual pilot frequency offset estimate value according to the phase difference within the range limited by the initial frequency offset value corresponding to the first frequency offset estimate value (S103); and acquiring a frequency offset estimate value of the current sub-frame according to the initial frequency offset value corresponding to the first frequency offset estimate value and the dual pilot frequency offset estimate value (S104).