Mobile Broadcast Data Timing for Stable VSB Reception
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Solution Overview
Problem
The Vestigial Sideband (VSB) transmission mode used in digital broadcasting in North America and Korea is prone to performance deterioration in poor channel environments, especially when using portable or mobile receivers, due to lack of resistance to channel changes and noise.
Innovation Solution
A digital broadcasting system that enhances receiving performance by performing additional encoding on mobile service data and inserting known data, allowing for better noise resistance and channel adaptability, while also processing service data at a constant bit rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If VSB transmission mode is used for digital broadcasting, then the system can maintain compatibility with existing standards and infrastructure, but receiving performance deteriorates in poor channel environments and mobile conditions
Solution Approach 1:
The patent applies preliminary action by inserting known data sequences into the transmitted signal before reception. These known sequences are predetermined and agreed upon between transmitter and receiver, allowing the receiver to perform channel estimation and equalization in advance, thereby improving receiving performance in mobile and noisy environments while maintaining VSB transmission compatibility
2Reliability
If additional encoding is performed on mobile service data, then noise resistance and channel adaptability improve, but system complexity increases
Solution Approach 1:
The patent performs preliminary encoding by inserting known data sequences into predetermined regions of the data stream before transmission. This preliminary action enables the receiver to establish channel characteristics in advance, improving noise resistance without requiring complex real-time encoding operations during reception
Solution Approach 2:
The patent applies local quality by inserting known data only in specific predetermined regions rather than throughout the entire data stream. This selective approach provides localized channel estimation where most needed while avoiding unnecessary complexity in processing entire data streams with uniform encoding
3Adaptability or versatility
If service data is processed discontinuously received on time axis, then data transmission flexibility increases, but maintaining constant bit rate becomes difficult
Solution Approach 1:
The patent uses feedback mechanisms where the receiver processes discontinuously received service data and generates feedback information about reception status and channel conditions. This feedback is transmitted back to the transmitter, which adjusts the transmitted data rate and encoding parameters accordingly, enabling constant bit rate processing at the receiver despite discontinuous reception patterns
Data Source
AI summary
A digital broadcasting system and a data processing method are disclosed. In an aspect of the present invention, the present invention provides a data processing method including receiving a broadcast signal in which main service data and mobile service data are multiplexed, demodulating the received broadcast signal, outputting demodulation time information of a specific position of a broadcast signal frame, and acquiring reference time information contained in the mobile service data frame, setting the reference time information to a system time clock at a specific time based on the demodulation time information and decoding the mobile service data according to the system time clock.