Receiver ADC Clock Delay for Echo Signal Cancellation
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Solution Overview
Problem
High-speed Ethernet networks face significant challenges in minimizing echo signal interference at receiver ADCs, leading to noise and non-linearity issues that constrain performance and reduce signal quality.
Innovation Solution
A full-duplex transceiver with a programmable delay line for the receiver ADC clock, allowing for adjustable timing to minimize echo signal effects, combined with digital processing circuitry for further echo cancellation using algorithms like MMSE and LMS, effectively reduces echo noise and improves signal linearity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If full-duplex transmission is implemented with parallel transmitter and receiver sections connected to the same twisted pair, then data transmission rate and bandwidth are improved, but echo signal interference increases causing noise and non-linearity at the receiver ADC
Solution Approach 1:
The patent uses the echo signal itself (the harmful factor) to generate a compensation signal that cancels the echo interference. By sampling the transmit signal and processing it through digital signal processing algorithms, the system converts the harmful echo into a useful cancellation signal that when subtracted from the received signal, eliminates the interference and improves receiver performance
Solution Approach 2:
The patent introduces an intermediary echo cancellation system between the receiver ADC and the received signal. This intermediary processing stage includes sampling circuits, digital signal processors, and compensation signal generators that mediate the interaction between the transmit and receive paths, filtering out the harmful echo components before they degrade the receiver ADC performance
2Object-affected harmful factors
If traditional DSP algorithms are used for echo cancellation, then some echo interference is reduced, but noise and non-linear components remain causing SNR loss
Solution Approach 1:
The patent replaces traditional mechanical/analog echo cancellation approaches with advanced digital signal processing techniques. By using digital sampling of the transmit signal and implementing sophisticated algorithms in the digital domain, the system achieves superior echo cancellation performance that preserves signal-to-noise ratio, overcoming the limitations of conventional DSP methods
3Object-affected harmful factors
If large amounts of echo signal are present at the receiver ADC, then echo cancellation processing is required, but the dynamic range of the receiver ADC is reduced constraining performance
Solution Approach 1:
The patent performs preliminary echo cancellation processing before the signal reaches the receiver ADC. By sampling the transmit signal early in the transmission path and generating compensation signals in advance, the system reduces the echo signal level before it enters the ADC, preserving the ADC's dynamic range and avoiding performance constraints
Data Source
AI summary
A device and method for a full-duplex transceiver is disclosed. The transceiver includes a transmitter DAC coupled to a transmission channel. The transmit DAC converting a digital transmission signal into an analog transmission signal. The transceiver further includes a receiver connected to the transmission channel. The receiver receives a desired signal and an echo signal, in which the echo signal includes at least a portion of the analog transmission signal. The receiver includes a receiver ADC, a programmable delay line for adjustably delaying a clock signal of the ADC, and a receiver processing circuit for adjusting the delay of the clock signal based at least in part upon the echo signal.