Sub-carrier Estimation Using Training Sequence Correlation
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Solution Overview
Problem
Existing sub-carrier estimation methods in multi-carrier communication systems suffer from low accuracy and high computational complexity, particularly in environments with interference, where methods like the Kolmogorov-Smirnov test or higher-order cyclic cumulant methods are required to improve accuracy but increase computational burden.
Innovation Solution
A method involving the extraction of a training sequence from a data frame, performing a fast Fourier transform, conjugate multiplication with a reference sequence, and averaging the real part of the result to estimate valid data transmission over sub-carriers, using preset thresholds to determine validity, thereby reducing computational complexity and improving accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If autocorrelation method is used for sub-carrier estimation, then the estimation process is simple, but the accuracy of estimation on number of sub-carriers and positions is poor
Solution Approach 1:
The patent introduces a training sequence as an intermediary element that is transmitted along with valid data. This training sequence serves as a mediator to enable accurate sub-carrier estimation without requiring complex mathematical models. The training sequence allows the receiving end to estimate sub-carrier information through correlation operations, resolving the contradiction between simplicity and accuracy.
2Measurement precision
If KS test method or higher-order cyclic cumulant method is used to improve estimation accuracy, then the accuracy of sub-carrier estimation improves, but the computational burden becomes very large
Solution Approach 1:
The patent extracts the essential function of sub-carrier estimation from complex mathematical models and implements it through a simplified correlation-based approach using the training sequence. By taking out the core estimation function and implementing it through basic correlation operations rather than KS tests or higher-order cumulants, the patent achieves accuracy while dramatically reducing computational burden.
3Measurement precision
If training sequence is added to data frame for accurate sub-carrier estimation, then the accuracy of sub-carrier estimation improves, but the data frame length increases
Solution Approach 1:
The patent applies partial action by using a training sequence of appropriate length that is sufficient for accurate sub-carrier estimation without unnecessarily increasing the data frame length. The training sequence length is optimized to provide the necessary estimation accuracy while minimizing the overhead, avoiding excessive action that would waste resources.
Data Source
AI summary
Provided are a sub-carrier estimation method in a multi-carrier communication system and an apparatus. The method includes: receiving a data frame transmitted by a transmitting end, and extracting a training sequence from the data frame; performing fast Fourier transform operation on the training sequence and a preset reference sequence, respectively, to obtain frequency domain data of the training sequence and frequency domain data of the reference sequence, and conjugately multiplying the two kinds of frequency domain data; extracting real part of conjugate multiplication result; averaging values in each column of an M×N array, respectively, to obtain an output array of 1 row and N columns; and estimating, according to the value in each column of the output array of 1 row and N columns, whether valid data is transmitted over N sub-carriers corresponding to the output array of 1 row and N columns.