PAM Eye Diagram Feedback for Receiver Equalizer Loss Compensation
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Solution Overview
Problem
High-speed signal transmission is hindered by insertion losses and noise, leading to intersymbol interference (ISI), which existing equalizer circuits struggle to fully compensate for, especially as transmission rates increase.
Innovation Solution
A receiver system incorporating time-interleaved analog-to-digital converters and equalizers that generate complementary digital information to adjust equalizer settings based on PAM eye diagram analysis, allowing for effective compensation of transmission losses and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If transmission rate is increased to improve productivity, then signal quality deteriorates due to insertion losses and noise
Solution Approach 1:
The patent divides the signal processing function into two separate receivers: a first receiver for normal data processing and a second receiver dedicated to PAM eye diagram generation and analysis. This segmentation allows the second receiver to specifically optimize for measuring insertion losses and noise without interfering with the main data path, enabling accurate compensation even at high transmission rates
Solution Approach 2:
The patent implements a feedback mechanism where the PAM eye diagram analysis from the second receiver provides information about insertion losses and noise, which is then used to adjust equalizer settings in the first receiver. This closed-loop feedback enables dynamic compensation for channel degradation, maintaining signal quality despite increased transmission rates
2Reliability
If equalizer compensation is increased to reduce ISI, then device complexity increases
Solution Approach 1:
The patent introduces a PAM eye diagram construction circuit as an intermediary that processes digitized samples from the second receiver. This intermediary generates visual representations of signal quality and extracts parameters for equalizer adjustment, providing a systematic bridge between raw signal measurements and equalizer control without requiring complex direct analysis circuits in the main path
Solution Approach 2:
The patent creates a copy of the reception path by implementing a second receiver that duplicates the basic signal reception functionality. This copy is dedicated solely to measurement and analysis purposes, allowing comprehensive PAM eye diagram generation and equalizer optimization without adding complexity to the primary data processing path
Data Source
AI summary
A method facilitates determining transmission loss in a transmission signal and adjusting a receiver setting of a receiver to compensate for the transmission loss. The method includes transmitting a transmission signal from a transmitter and receiving the transmission signal by a first receiver and a second receiver. The method includes digitizing the transmission signal by the first receiver at a first sampling frequency and digitizing the transmission signal by the second receiver at a second sampling frequency that is less than or equal to the first sampling frequency. The method includes generating a PAM-n eye diagram of the transmission signal by the second receiver using digitized signals digitized by the first and second receivers and adjusting an equalizer setting of a first equalizer of the first receiver using eye-opening information of the PAM-n eye diagram where the eye-opening information includes information for the transmission loss.