Digital Signal Quality Metric via Correlation Waveform Normalization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing digital radio broadcasting systems lack an effective and efficient method for determining the quality of received digital signals, particularly in hybrid and all-digital formats, which is crucial for applications like seek-scan functions and interferer resolution, and requires minimal changes to existing HD Radio™ receiver hardware or software.
Innovation Solution
A method and apparatus that calculates a digital signal quality metric by receiving a digital radio signal, developing a correlation waveform, normalizing it, and determining peak values for upper and lower sidebands, with optional validation through peak index delta and frequency offset difference calculations, to distinguish between desired signals and adjacent interferers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If no signal quality metric is implemented, then receiver hardware and software remain simple, but applications like seek-scan functions and interferer resolution cannot be performed accurately
Solution Approach 1:
The correlation waveform calculation, already performed for signal acquisition in existing HD Radio receivers, is repurposed to provide both acquisition functionality and signal quality metric calculation. This multi-functional approach enables accurate signal quality assessment without adding separate dedicated hardware or software components, thus improving measurement precision while minimizing device complexity.
2Reliability
If a comprehensive signal quality metric with validation is implemented, then signal quality assessment becomes reliable and accurate, but calculation time and processing complexity increase
Solution Approach 1:
The correlation waveform is calculated in advance as part of the signal acquisition process before formal signal processing begins. This preliminary calculation serves dual purposes: enabling signal acquisition and providing the basis for quality metric calculation. By performing this computation beforehand, the system avoids redundant calculations during actual signal processing, thereby improving reliability through validation while minimizing additional calculation time.
3Measurement precision
If signal quality metric calculation is added to existing receivers, then accurate signal quality assessment is achieved, but changes to existing HD Radio receiver hardware or software are required
Solution Approach 1:
The invention reuses the correlation waveform calculation that already exists in HD Radio receivers for signal acquisition purposes. By extracting the quality metric from this existing computation rather than implementing a separate measurement system, the patent achieves accurate signal quality assessment while minimizing changes to existing receiver hardware and software architecture.
4Measurement precision
If validation through peak index delta and frequency offset difference is performed, then distinction between desired signals and adjacent interferers is improved, but device complexity increases
Solution Approach 1:
The validation process uses feedback from the correlation waveform characteristics (peak index position and frequency offset) to verify signal quality and distinguish desired signals from interferers. By utilizing already-calculated parameters from the correlation process and applying simple threshold-based validation, the system achieves high interferer resolution accuracy without implementing complex additional processing algorithms.
Data Source
AI summary
A method for detecting a digital radio signal includes the steps of receiving the digital radio signal including a series of symbols, developing a correlation waveform having a peak that corresponds to a symbol boundary, normalizing the correlation waveform, and calculating a peak value of the normalized correlation waveform, wherein the peak value represents the quality of the received digital radio signal. A receiver that performs the method is also provided.