Receiver Equalizer Calibration Using Blind Channel Estimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing communication systems face challenges in accurately estimating dispersive channels, particularly in receivers for pulse amplitude modulation (PAM) signals, due to issues like intersymbol interference and frequency attenuation, which affect signal recovery and equalizer tuning, and current blind channel estimation methods are inefficient in power consumption and tuning time.
Innovation Solution
The method employs an analog conditional one counting circuit with event indicators and delay units to generate sliced and offsetted signals, which are then used to calculate a conditional ones signal to calibrate the equalizer, enabling effective blind channel estimation by measuring signal histograms and conditional ones ratios to derive channel pulse response.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If blind channel estimation is performed using conventional methods, then channel estimation can be achieved, but power consumption is high and tuning time is long
Solution Approach 1:
The patent extracts only the essential statistical features (signal histogram and conditional ones ratio) needed for channel estimation, rather than performing complete signal processing. This selective extraction reduces computational complexity and power consumption while maintaining estimation accuracy.
Solution Approach 2:
The receiver performs self-calibration by automatically measuring signal statistics and adjusting equalizer parameters without external intervention or training sequences. This self-service approach eliminates the need for power-intensive pilot signals or manual tuning procedures.
2Measurement precision
If blind channel estimation is performed using conventional methods, then channel estimation can be achieved, but tuning time is long
Solution Approach 1:
The patent performs preliminary measurements of signal histogram and conditional ones ratio that can be continuously updated in the background. When channel estimation is needed, the pre-collected statistical data is already available, significantly reducing the time required for tuning compared to conventional methods that must start from scratch.
Solution Approach 2:
The signal statistics measurements are performed continuously rather than intermittently, allowing the receiver to maintain an up-to-date understanding of channel conditions. This continuous monitoring enables rapid adaptation to channel changes without requiring lengthy re-tuning periods.
3Measurement precision
If signal slicing and offsetting are applied to generate conditional ones signal, then equalizer calibration accuracy is improved, but device complexity increases
Solution Approach 1:
The patent segments the signal processing into distinct functional blocks: slicing unit that separates signal levels, offsetting unit that shifts signal levels, and conditional ones generation unit that combines them. This segmentation allows each function to be implemented with simple, dedicated circuitry rather than a complex general-purpose processor.
Solution Approach 2:
The patent introduces intermediate signals (sliced signal, offsetted signal, conditional ones signal) that act as mediators between the raw received signal and the final equalizer calibration. These intermediate representations simplify the complexity of direct calibration by breaking down the complex operation into simpler sequential steps.
Data Source
AI summary
Embodiments are disclosed for channel estimation in a receiver of a communication system. An example method includes receiving, via a receiver of a communication system, an input signal. The example method further includes using a first event indicator embedded in an analog circuit of the receiver to slice the input signal to generate a sliced input signal and applying an offset to the input signal to generate an offsetted signal. The example method further includes using a second event indicator embedded in the analog circuit to slice the offsetted signal to generate a sliced offsetted signal. The example method further includes applying a first predefined delay to the sliced input signal and applying a second predefined delay to the sliced offsetted signal. The example method further includes generating a conditional ones signal based on the sliced input signal and the sliced offsetted signal and using the conditional ones signal to calibrate an equalizer embedded in the receiver.