Echo Canceller Channel Detection Using Tap Weight Comparison
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional channel detection methods in cable communication systems require additional hardware and longer testing times, especially when both ends of a channel perform detection simultaneously, leading to increased costs and interference issues.
Innovation Solution
A channel detection method using an echo canceller that transmits a detection signal, receives reflected taps, compares them with reference values, and records positions where taps exceed these values, allowing for dual-ended detection without additional hardware and reducing testing time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If auto-correlation is used for channel detection, then channel detection can be performed, but additional hardware implementation is required and testing time increases
Solution Approach 1:
The echo canceller, originally designed for echo suppression, is made to perform dual functions: both echo cancellation and channel detection. By utilizing the existing tap weights and convergence properties of the echo canceller, the patent enables channel detection without requiring separate dedicated hardware, thus resolving the contradiction between detection capability and hardware complexity
Solution Approach 2:
The echo canceller uses its own internal resources (tap weights, convergence calculation mechanism) to perform channel detection. The tap weights already computed for echo cancellation are directly utilized for detection purposes, making the system self-sufficient and eliminating the need for additional hardware implementations
2Reliability
If auto-correlation is used for channel detection, then channel detection can be performed, but testing time increases
Solution Approach 1:
The echo canceller performs preliminary convergence calculation during normal operation, and this converged state is directly utilized for channel detection. By preparing the tap weights in advance through normal echo cancellation operation, the actual detection process becomes much faster, resolving the time loss issue
Solution Approach 2:
The echo canceller maintains continuous operation and convergence during normal communication, and this continuous state is seamlessly transitioned to detection mode. The useful action of echo cancellation continues to provide updated tap weights that are immediately available for detection, eliminating the need for separate detection initialization and reducing testing time
3Productivity
If both ends perform channel detection simultaneously, then detection efficiency improves, but cross-talk and mutual interference occur
Solution Approach 1:
The patent utilizes the feedback mechanism inherent in echo cancellation to detect reflected signals. By monitoring the feedback path and comparing tap weights, the system can identify channel conditions without transmitting high-energy detection signals that would cause cross-talk, enabling simultaneous dual-ended detection without interference
Data Source
AI summary
A channel detection method for an echo canceller of a communication device is provided. The method includes the following steps. A first detection signal is transmitted to an end of a channel coupled to the communication device. A plurality of taps corresponding to a reflected signal of the first detection signal are received by an echo canceller at the end of the channel. The taps corresponding to the reflected signal are compared with a reference value corresponding to each of the taps so as to determine whether each of the taps is larger than or equal to the corresponding reference value. When the tap is determined to be larger than or equal to the reference value corresponding to the tap, the tap and a position of the tap are recorded.