Timing and Frequency Offset Correction in Wireless Receivers
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Solution Overview
Problem
In wireless communications, timing and frequency offsets cause signal distortions that hinder proper demodulation, and existing methods struggle to accurately estimate and correct these offsets, especially in multipath channels and non-reciprocal MIMO/SISO systems.
Innovation Solution
A processor-implemented method that estimates and corrects timing and frequency offsets using various techniques such as upsampling, downsampling, and singular value decomposition, allowing for the detection of effective channels and generation of encoded data for precise signal transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If timing and frequency offsets are present in wireless communications, then signal transmission can occur over distance, but signal distortion increases and demodulation accuracy deteriorates
Solution Approach 1:
The patent applies preliminary action by estimating and correcting timing and frequency offsets before the main signal demodulation process. The method performs offset estimation using training sequences or signal features, generates correction parameters, and applies these corrections to the received signal prior to channel estimation and decoding, thereby preparing the signal for accurate demodulation despite the presence of distortions
Solution Approach 2:
The patent implements feedback mechanisms where the receiver estimates timing and frequency offsets based on received signals, generates correction information, and feeds back corrected signal parameters to subsequent processing stages. The system continuously monitors signal quality and adjusts correction parameters to maintain optimal demodulation accuracy under varying channel conditions
2Reliability
If existing offset correction methods are used, then some signal distortion can be mitigated, but accuracy deteriorates in multipath channels and non-reciprocal MIMO/SISO systems
Solution Approach 1:
The patent applies parameter changes by adapting the offset estimation and correction parameters to specific channel conditions. The system identifies whether the channel is multipath or non-reciprocal MIMO/SISO, and adjusts estimation parameters accordingly - using different correction matrices, adjustment factors, and processing algorithms tailored to each channel type to maintain high estimation accuracy across diverse communication scenarios
Solution Approach 2:
The patent implements dynamics by making the offset correction system adaptive and configurable based on detected channel characteristics. The receiver dynamically switches between different correction algorithms and parameter sets depending on whether multipath or non-reciprocal conditions are detected, allowing the system to optimize performance for each specific channel environment rather than using a fixed correction approach
Data Source
AI summary
A processor-implemented method includes receiving a signal representing a first encoded data and calculating an estimated timing offset and/or an estimated frequency offset associated with the signal. A correction of at least one of a timing offset or a frequency offset of the signal is performed based on the estimated timing offset and/or the estimated frequency offset, to produce a modified signal. An effective channel is subsequently detected based on the signal or the modified signal. A second encoded data is generated based on the modified signal, a known vector, at least one left singular vector of the effective channel, and at least one right singular vector of the effective channel. A signal representing the second encoded data is transmitted to a communication device for identification of contents of a message at a different processor.