Single-Chip Digital BTSC Encoder Anti-Splatter Filter
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional BTSC encoders are expensive, complex, and not suitable for consumer applications due to their analog approach, which degrades over time and requires external converters, leading to noise issues when combining stereo channels.
Innovation Solution
A single-chip digital BTSC encoder with a dual-channel Sigma-Delta ADC, audio processor, sync separator, and anti-splatter filter generates a composite audio signal directly, reducing noise and simplifying system design by performing all processing digitally.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional analog BTSC encoding is used, then broadcast quality audio can be achieved, but the system becomes expensive, complex, and requires substantial space
Solution Approach 1:
The patent replaces the traditional analog mechanical/electronic system with a digital system. The analog BTSC encoder is substituted with a digital signal processor that performs BTSC encoding through digital signal processing algorithms, eliminating the need for complex analog circuitry while maintaining audio quality
Solution Approach 2:
The patent changes the fundamental operating parameter from analog continuous signals to digital discrete signals. This parameter change enables the use of digital processing techniques that are more compact, stable, and cost-effective while preserving the audio encoding functionality
2Ease of manufacture
If analog circuitry is used for BTSC encoding, then the encoding function can be performed, but the device is subject to environmental and aging effects that degrade performance
Solution Approach 1:
The patent substitutes analog circuitry with digital circuitry. Digital circuits are immune to environmental factors like temperature and humidity, and do not suffer from aging effects that cause drift in analog components, thereby significantly improving long-term performance stability
3Adaptability or versatility
If digital signal processor or FPGA is used for BTSC encoding, then consumer application suitability improves, but the cost increases due to expensive external converters
Solution Approach 1:
The patent merges the digital signal processing functions with the audio encoding functions into a single integrated system. By combining the DSP capabilities with the BTSC encoder in one unit, the need for separate external ADCs, DACs, and sync separators is eliminated, reducing overall system cost
Solution Approach 2:
The patent creates a multi-functional integrated circuit that performs multiple functions: digital-to-analog conversion, synchronization separation, audio processing, and BTSC encoding. This universal device replaces multiple separate components, making the system more cost-effective for consumer applications
4Productivity
If the modulated L-R channel is combined with the L+R channel in traditional digital encoders, then a composite audio signal is generated, but out-of-band noise from the L-R channel degrades overall system performance
Solution Approach 1:
The patent extracts and removes the out-of-band noise from the modulated L-R channel before combining it with the L+R channel. This is achieved through digital filtering techniques that selectively eliminate noise frequencies while preserving the desired audio signal components
Solution Approach 2:
The patent converts the harmful out-of-band noise into a manageable signal component through digital filtering. The noise is identified, isolated, and removed in the digital domain, transforming a degradation factor into an opportunity for enhanced signal quality through selective processing
Data Source
AI summary
A BTSC encoder includes dual channel ADC, sync separator, audio processor, filtering device, and a composite audio signal generating device. The filtering device includes a first filter for providing a filtered L+R signal, and a second filter for providing at least one of: i) a filtered and combined pilot and modulated L−R signal and ii) separately filtered pilot and modulated L−R signals. The composite audio signal generating device is responsive to the filtered L+R signal, and at least one of i) the filtered and combined pilot and modulated L−R signal and ii) the separately filtered pilot and modulated L−R signals for generating and outputting a composite analog audio signal. In all embodiments, the modulated L−R signal is filtered via an anti-splatter filter.