Network Apparatus Ports with Adaptive Interference Cancellation
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Solution Overview
Problem
Conventional communication systems face challenges in accurately canceling cross-clock-domain interference between communication ports, particularly in HDMI Ethernet channels, due to computational errors and increased complexity when using Farrow structures, which degrade performance and prolong time delays.
Innovation Solution
A network apparatus with multiple communication ports, each equipped with an echo canceller, near-end crosstalk canceller, and decision feedback equalizer, controlled by a unit that updates coefficients based on specific timing intervals to eliminate interference, using adaptive filters and algorithms like LMS or RLS to rapidly converge and reduce phase differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If Farrow structure is used for clock domain switching, then interpolating calculation complexity is reduced, but computational precision deteriorates due to polynomial approximation errors
Solution Approach 1:
The patent segments the interference cancellation process into multiple independent filters (echo canceller, NEXT canceller, cross-port NEXT canceller, decision feedback equalizer), each handling specific types of interference separately. This allows each filter to be optimized independently, maintaining precision while managing complexity through modular architecture.
Solution Approach 2:
The patent implements dynamic control of filter coefficient updates based on operational mode (master/slave) and timing intervals. The control unit dynamically enables or disables coefficient updates for different filters depending on the communication port's role and the current time interval, adapting the system behavior to operational conditions to maintain precision while reducing unnecessary computations.
2Measurement precision
If high-order polynomial is used in Farrow structure to improve interpolating accuracy, then computational precision is improved, but device complexity and time delay increase
Solution Approach 1:
The patent divides the single complex Farrow structure into multiple specialized filters (echo canceller with first coefficients, NEXT canceller with second coefficients, decision feedback equalizer with third coefficients). Each filter uses a manageable number of taps optimized for its specific function, avoiding the need for a high-order polynomial with excessive taps while maintaining overall system precision.
Solution Approach 2:
The patent implements periodic control of filter updates by the control unit, which enables or disables coefficient updates based on timing intervals and operational modes. This periodic action reduces the average computational load and time delay while maintaining precision when updates are necessary, avoiding continuous high-complexity operations.
3Ease of manufacture
If multiple communication ports share the same transformer coils, then production cost is reduced, but signaling performance deteriorates due to port interference
Solution Approach 1:
The patent converts the harmful port interference caused by shared transformer coils into a manageable signal characteristic. By implementing multiple specialized cancellers that specifically target and cancel different types of interference (echo, NEXT, cross-port NEXT), the system transforms the unavoidable physical interference into a correctable signal degradation, maintaining reliable communication despite the cost-effective shared coil architecture.
Solution Approach 2:
The patent changes the operational parameters of the communication ports by assigning different seeds to ports operating in master mode and implementing mode-dependent control of filter updates. This parameter differentiation allows the system to manage interference patterns caused by shared coils, ensuring that signaling performance is maintained through adaptive parameter adjustment rather than requiring physical isolation of ports.
4Speed
If echo canceller and decision feedback equalizer update coefficients simultaneously during the same time interval, then convergence speed is improved, but computational accuracy deteriorates due to seed collision
Solution Approach 1:
The patent implements dynamic, conditional control of coefficient updates based on the communication port's operational mode (master or slave) and the current time interval. The control unit dynamically determines which filters should update their coefficients at any given time, enabling parallel updates for different filter types under controlled conditions while preventing harmful simultaneous updates that cause seed collision, thus balancing convergence speed and computational accuracy.
Data Source
AI summary
This disclosure provides a network apparatus with communication ports, each connected to multiple channels, assigned a seed for eliminating the interference among the communication ports, and operable in a master or slave mode, each channel having a communication unit which comprises: an echo canceller, a near-end crosstalk (NEXT) canceller, a decision feedback equalizer, and a control unit configured for controlling the communication ports if the echo canceller and the decision feedback equalizer keep updating their filter coefficients according to the same symbol during a first pre-determined time-interval; wherein when more than two of the communication ports operate in the master mode, the control unit assigns different seeds to the more than two communication ports; and wherein when successive two of the communication ports operate in the slave mode, the control unit stops either the echo canceller or the NEXT canceller from updating their filter coefficients during a second pre-determined time-interval.