Single Carrier Equalizer Iterative Feedback for Multipath Interference
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Solution Overview
Problem
Existing single carrier equalizers fail to effectively address distortion in wireless data transmission, especially under limited bandwidth and multipath conditions, and perform poorly under narrowband interference, leading to reduced receiver system performance.
Innovation Solution
A single carrier equalizer is enhanced with an iterative updater that performs frequency domain equalization using specific iterative formulas, incorporating an inverse fast Fourier transformer and a signal decision device to improve anti-multipath and mobile performance, and reduce the impact of narrowband interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a time domain equalizer or frequency domain equalizer is used in prior art, then basic equalization function is provided, but performance is poor under multipath and narrowband interference conditions
Solution Approach 1:
The patent implements an iterative equalization process where the equalizer output is fed back through a decision device and re-encoder, with the result fed back to update the equalization filter coefficients. This feedback mechanism allows the equalizer to progressively improve performance by using previous iteration results to refine subsequent equalization, effectively addressing multipath and narrowband interference while maintaining manageable complexity through controlled iteration
Solution Approach 2:
The patent employs dynamic adaptation of equalization parameters through iterative updates. The equalization filter coefficients are dynamically adjusted based on feedback from decision devices and re-encoders, allowing the system to adapt to changing channel conditions including multipath fading and narrowband interference, thereby improving reliability without requiring a permanently complex structure
2Reliability
If iterative equalization is implemented to improve frequency domain equalization performance, then anti-multipath and mobile performance is enhanced, but calculation complexity increases
Solution Approach 1:
The patent implements iterative equalization with a predetermined maximum number of iterations or stopping criteria based on convergence thresholds. Rather than performing infinite or excessive iterations, the system performs a controlled number of iterative passes through the equalization, decision, and feedback process, achieving sufficient performance improvement for anti-multipath and mobile conditions while limiting computational complexity through these stopping conditions
3Reliability
If narrowband interference is present in the frequency domain, then equalization performance is greatly reduced, but adding complexity to address it is undesirable
Solution Approach 1:
The patent extracts and separately processes narrowband interference components through the iterative feedback mechanism. By transforming the signal through FFT, applying equalization, and feeding back decision results, the system isolates and corrects narrowband interference effects in the frequency domain without requiring separate dedicated interference cancellation hardware, thus improving reliability while avoiding excessive complexity
Solution Approach 2:
The patent introduces an intermediary iterative feedback process that mediates between the equalized signal and the final output. The decision device and re-encoder act as intermediaries that process the equalized signal, identify errors caused by narrowband interference, and feed correction information back to refine the equalization, thereby mitigating interference effects without directly complex interference cancellation mechanisms
Data Source
AI summary
The invention relates to the field of the equalizer, more specifically, to a single carrier equalizer and a receiver system comprises the single carrier equalizer. It is used to gradually improve the performance of the frequency domain equalizer by the way of iterations. The present invention uses an iterative updater to conduct a first iteration based on the frequency domain value of the input signal and the frequency domain value of the channel of the input signal, and transmits the iteration result to the inverse fast Fourier transformer. And the signal decision device is used to judge the value of the output of the inverse fast Fourier transformer, and the output signal of the signal decision device is transmitted to the fast Fourier transformer and the iterative updater respectively.