Frequency Offset Estimation in Wireless Communication Systems
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Solution Overview
Problem
In wireless communication systems, accurately estimating a frequency offset with low complexity is challenging due to differences in carrier frequencies between transmitting and receiving devices.
Innovation Solution
A method and device for estimating a frequency offset by receiving signals with reference signal groups, calculating residual frequency offsets, compensating signal phases, and estimating channels based on these signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional frequency offset estimation methods are used, then carrier frequency alignment is achieved, but estimation accuracy is insufficient and complexity increases
Solution Approach 1:
The patent segments the frequency offset estimation process into two distinct stages: a first estimation using initial reference signals, and a second estimation using subsequent reference signals. This segmentation allows each estimation to be optimized independently, improving overall accuracy while managing computational complexity through staged processing rather than attempting a single complex estimation
Solution Approach 2:
The patent performs a preliminary frequency offset estimation using the first reference signals before processing the second reference signals. This preliminary action establishes an initial frequency alignment that facilitates more accurate second estimation, as the receiver is already partially synchronized when receiving the second reference signals
2Measurement precision
If multiple reference signal groups are used for estimation, then estimation accuracy improves, but processing complexity and time increase
Solution Approach 1:
The patent divides reference signals into multiple groups received at different times and processes them in sequential stages. The first reference signal group is processed for initial frequency and channel estimation, then the second reference signal group is processed for refined estimation. This segmentation enables accurate multi-group processing without requiring all signals to be processed simultaneously, reducing time loss
Solution Approach 2:
The patent maintains continuous frequency offset compensation throughout the reception of multiple reference signal groups. By continuously applying frequency offset correction based on ongoing estimations, the system充分利用 each received reference signal group without idle processing time, ensuring that useful estimation actions continue without interruption across multiple signal receptions
Data Source
AI summary
An operation method of a wireless communication device includes receiving a first signal including a first reference signal group, calculating a first residual frequency offset based on the first signal, receiving a second signal that is subsequent to the first signal and includes a second reference signal group, compensating a phase of the second signal based on the first residual frequency offset, estimating a first channel based on first channel characteristics, the first reference signal group, and the first signal, estimating a second channel based on second channel characteristics, the second reference signal group, and the second signal of which the phase is compensated, and calculating a second residual frequency offset based on the first channel estimation and the second channel estimation.