Radio Communication System Carrier Frequency Offset Estimation
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Solution Overview
Problem
Conventional radio communication systems face challenges in accurately estimating carrier frequency offsets in multi-path environments, leading to degraded transmission characteristics and increased estimation time, power consumption, and frame use efficiency due to the need for longer training signals and higher transmission power.
Innovation Solution
A radio communication system that transmits radio signals with frequency offsets assigned to training signals, allowing for accurate carrier frequency offset estimation with a shorter training signal length or lower transmission power by using a phase difference detection method that averages physical amounts based on phase shift amounts, even in multi-path fading environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a longer training signal is used to accurately estimate carrier frequency offset in multi-path environments, then estimation accuracy is improved, but estimation time and frame use efficiency deteriorate
Solution Approach 1:
The patent changes the parameter of training signal structure by introducing frequency offset assignment to training signals. Instead of using longer training signals to improve accuracy, the system assigns specific frequency offsets to training signals and uses phase difference detection to estimate carrier frequency offset, achieving accurate estimation with shorter training signal length and reduced estimation time.
2Measurement precision
If higher transmission power is used to improve carrier frequency offset estimation accuracy, then estimation precision is improved, but power consumption and transmission power requirements increase
Solution Approach 1:
The patent replaces the conventional approach of using higher transmission power to improve estimation accuracy with a signal processing approach. By assigning frequency offsets to training signals and using phase difference detection, the system achieves accurate carrier frequency offset estimation without requiring higher transmission power, thus reducing power consumption.
3Measurement precision
If training signals are used to estimate carrier frequency offset, then estimation accuracy is improved, but transmission efficiency deteriorates due to unnecessary training signals
Solution Approach 1:
The patent segments the training signal into multiple parts with different frequency offsets assigned to them. This segmentation allows the receiver to use phase difference detection across these segmented signals to estimate carrier frequency offset more accurately, reducing the need for longer training sequences and improving transmission efficiency.
Data Source
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AI summary
A radio communication system includes a transmission device which transmits a plurality of radio signals, and a reception device which receives the plurality of radio signals from the transmission device and estimates, as a carrier frequency offset, a difference between a carrier frequency transmitted by the transmission device and a reference reception frequency used for reception. The system includes the transmission device which branches a first previously determined sequence of training signals, and transmits the radio signals modulated with frequencies by the carrier frequency offsets having regularity for a first sequence of a plurality of branched training signals, and the reception device which estimates the carrier frequency offset with the transmission device according to the first sequence of training signals included in the radio signals transmitted from the transmission device and phase shift amounts obtained from the first previously determined sequence of training signals.