Full-Duplex Transmission Medium Testing via Auto-Correlation Signal Analysis
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Solution Overview
Problem
Existing transmission medium testing methods are limited to half-duplex communication systems and cannot determine the location and condition of impedance-mismatching points in full-duplex systems due to echo interference.
Innovation Solution
A method and apparatus using a test signal sequence with high auto-correlation, such as a Pseudo-noise sequence, to transmit and receive signals, allowing for correlation operations to distinguish between echo and reflected signals, and determine impedance matching conditions in full-duplex systems by adjusting signal phases and calculating energy levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a pulse wave is transmitted from endpoint A to test the cable, then the reflected wave can be detected to determine impedance-mismatching points, but in full-duplex systems the endpoint A receives both the reflected wave and the transmitting wave from endpoint B, making it impossible to determine the location and condition of impedance-mismatching points
Solution Approach 1:
The patent applies preliminary action by transmitting a test signal sequence with high auto-correlation properties before normal communication occurs. This allows the system to establish a known reference signal that can be used for correlation analysis, enabling the distinction between echo and reflected waves even when both are present during full-duplex operation. The test signal sequence is prepared and transmitted in advance to facilitate subsequent correlation operations.
Solution Approach 2:
The patent uses correlation operation as an intermediary mechanism to separate and identify the reflected wave from the echo signal. By correlating the received signal with the transmitted test signal sequence, the system creates an intermediary processing step that filters out the echo interference and isolates the reflected wave components, enabling accurate detection of impedance-mismatching points despite the presence of simultaneous transmissions.
2Device complexity
If the prior art cable testing method is applied to full-duplex networks, then the testing process can be simplified, but the echo effect at the receiving end prevents determination of impedance-mismatching point location and condition
Solution Approach 1:
The patent applies parameter changes by modifying the test signal characteristics to have high auto-correlation properties. This parameter change enables the correlation operation to distinguish between signals with different temporal patterns, allowing the system to identify reflected waves even when echo signals are present. The change in signal parameters (using pseudo-random sequences with high auto-correlation) provides the necessary discrimination capability for reliable detection.
Solution Approach 2:
The patent replaces the simple pulse wave transmission method with a correlation-based signal processing system. Instead of relying on straightforward pulse reflection detection, the system uses correlation operations to analyze signal patterns, substituting mechanical/simple detection with a more sophisticated signal processing approach that can handle the complexity of full-duplex environments.
3Measurement precision
If a test signal sequence with high auto-correlation is transmitted and correlation operation is performed, then echo and reflected signals can be differentiated, but the system complexity increases due to additional signal processing circuits
Solution Approach 1:
The patent applies self-service by using the transmitted test signal sequence itself as the reference for correlation operation. The system correlates the received signal with the known transmitted sequence, allowing the transmitted signal to serve its own purpose as both the test stimulus and the reference for analysis. This self-service approach eliminates the need for separate reference signals and simplifies the overall system architecture.
Solution Approach 2:
The patent makes the test signal sequence serve multiple functions: it acts as both the transmission test stimulus and the correlation reference signal. This multi-functionality reduces the need for separate components and simplifies the system, as the same signal sequence is used for both transmitting test data and performing correlation analysis to differentiate echo and reflected waves.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate detection and location of impedance-mismatching points in full-duplex communication systems, such as 1000 Mbps Ethernet, by differentiating between echo and reflected signals and determining phase differences, thus improving the reliability of transmission medium testing.
Implementation Method 1
a correlation operation is performed on the transmitted signal and the received signal
Implementation Method 2
the transmitted signal will generate an echo effect at the receiving end (Rx)
Data Source
AI summary
The invention provides a method for testing a transmission medium used in a full-duplex communication system comprising an endpoint that comprises a transmitting end (TX) and a receiving end (RX); the method comprises the steps of: first, transmitting a transmitted signal which comprises a test signal sequence with a high auto-correlation characteristic; then, receiving a received signal, and performing a correlation operation on the test signal and the received signal; finally, according to the result of the correlation operation, determining the impedance matching condition of the transmission medium.