Multi-band filter signal detection mitigating narrowband interference
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Solution Overview
Problem
High-speed communication systems in vehicles face interference from sources like ignition systems, cellular phones, and atmospheric conditions, which can corrupt training signals and prevent proper synchronization and gain setting in receivers, leading to signal degradation or failure during initialization.
Innovation Solution
The use of a multi-band filter system that processes the communication signal through sub-band filters to detect the presence of a training signal and measure power, allowing for robust and efficient signal detection and gain setting even in the presence of narrowband interference by comparing power measurements across sub-bands and setting gains based on unaffected measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If narrowband interference is present during signal reception, then power measurements become biased and signal detection becomes unreliable, but using traditional single-band filtering cannot sufficiently mitigate the interference
Solution Approach 1:
The patent divides the frequency spectrum into multiple sub-bands using parallel bandpass filters with different center frequencies. By segmenting the broad bandwidth into narrower sub-bands, the system can identify and exclude sub-bands contaminated by narrowband interference when performing power measurements, thereby maintaining reliable signal detection despite the presence of interference.
2Measurement precision
If traditional power measurement methods are used in the presence of interference, then gain setting becomes improper and receiver performance degrades, but the patent's multi-band approach adds system complexity
Solution Approach 1:
The patent employs multiple parallel bandpass filters, each covering a specific sub-band of the total bandwidth. This segmentation allows the system to perform power measurements on individual sub-bands and selectively exclude interfered sub-bands from the average power calculation, improving measurement accuracy while keeping each individual filter relatively simple.
Solution Approach 2:
The patent introduces an intermediary processing stage that calculates power measurements for each sub-band separately and then combines them to determine the overall signal power. This intermediary approach allows the system to mitigate narrowband interference by excluding affected sub-bands from the final power measurement, improving accuracy without requiring complex adaptive filtering algorithms.
3Productivity
If the receiver uses full bandwidth processing for signal detection, then initialization speed is faster, but narrowband interference corrupts the training signal detection
Solution Approach 1:
The patent segments the bandwidth into multiple parallel sub-bands that are processed simultaneously. This allows the system to maintain fast initialization by processing multiple sub-bands in parallel rather than sequentially, while still being able to identify and exclude interfered sub-bands from the final signal detection decision.
Solution Approach 2:
The patent processes more sub-bands than strictly necessary for minimum functionality, using a multi-band approach that exceeds the simple single-band solution. By processing multiple sub-bands in parallel and selectively combining their results, the system achieves both fast initialization and robust interference mitigation, accepting some additional processing overhead for significantly improved reliability.
Data Source
AI summary
Various aspects of this disclosure describe detecting a signal and measuring power with a multi-band filter. Examples include a signal detection and power measurement module in a receiver capable of detecting a training signal and calculating a reliable power measurement in the presence of narrowband interference. A received signal is filtered by a multi-band filter comprising a plurality of sub-band filters. For instance, sub-band filters may be bandpass filters with non-overlapping pass-bands. A training signal is detected by comparing powers of each of the outputs of the sub-band filters to a plurality of thresholds. For example, each sub-band may be assigned a different threshold value. Responsive to detecting a training signal, a power measurement is determined from at least one sub-band filter output. A gain is set based on the determined power measurement, and applied in the receiver.