Wired Channel Probing During Concurrent Multi-Transmitter Operation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current MoCA systems inaccurately characterize wired communication channels when multiple devices are transmitting simultaneously, leading to inefficiencies in bandwidth usage due to the need for error vector magnitude (EVM) probes being sent only from a single active device, which does not account for concurrent transmissions.
Innovation Solution
The method involves transmitting an EVM probe packet from one device while other devices are active, with some devices transmitting an analog zero signal to maintain consistent impedance, allowing network devices to estimate channel characteristics like signal-to-noise ratio and data capacity even when multiple transmitters are active.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If EVM probes are transmitted only from a single device at a time, then channel characteristics can be measured, but bandwidth efficiency deteriorates due to inability to utilize full network capacity during probing
Solution Approach 1:
The patent combines multiple transmission functions into a single probing operation. Multiple devices transmit their EVM probes simultaneously on different subcarriers during the same OFDMA symbol period, merging what were previously separate sequential operations into one concurrent operation, thereby maintaining measurement accuracy while improving bandwidth efficiency
Solution Approach 2:
The patent enables continuous channel characterization by eliminating idle periods between sequential probes. By allowing multiple devices to probe concurrently, the system maintains continuous utilization of network resources without the downtime that would occur if devices had to wait for their turn to transmit probes
2Productivity
If multiple devices transmit simultaneously during channel measurement, then bandwidth efficiency improves, but measurement precision deteriorates due to interference from other transmitters
Solution Approach 1:
The patent segments the frequency spectrum into multiple orthogonal subcarriers, assigning each device's EVM probe to a specific subcarrier. This segmentation allows simultaneous transmissions to coexist without interference, as each device operates on its designated frequency portion while collectively utilizing the full bandwidth
Solution Approach 2:
The patent transitions from time-division multiplexing (sequential probing in different time slots) to frequency-division multiplexing (concurrent probing on different subcarriers). This dimensional change from time to frequency domain enables simultaneous measurements without mutual interference
3Measurement precision
If EVM probes are transmitted in all possible transmission scenarios, then measurement precision improves by covering all device combinations, but device complexity increases due to extensive probing requirements
Solution Approach 1:
The patent creates a universal probing mechanism that functions across all transmission scenarios simultaneously. By enabling concurrent multi-device probing, a single system configuration can handle any combination of active devices without requiring separate probing procedures for each scenario, thereby reducing system complexity
Data Source
AI summary
Various systems and methods for probing a communication channel. These systems and methods transmit an error vector probe packet from a first transmitter while a second transmitter is active and transmitting. A network device may receive the error vector probe packet and measure an error vector magnitude based on the received error vector probe packet. Using the error vector magnitude, the network device estimates channel characteristics such as signal-to-noise ratio, data capacity, etc. The transmission can occur when more than one transmitter is active and transmitting. At least some of the other transmitters are active and transmit an analog zero signal, e.g., all digital zeros on the input to the digital-to-analog converter of a network device when an error vector probe packet is transmitted.