Mobile VSB Broadcasting with Known Data for Robust 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 with portable and mobile receivers, due to insufficient resistance to channel changes and noise.
Innovation Solution
A digital broadcasting system that performs additional encoding on mobile service data and inserts known data in specific regions of the data group, allowing for robust error correction and improved receiving performance, even in noisy conditions, by using a service multiplexer and transmitter to multiplex and encode mobile and main service data, and a receiving system with a signal receiving unit, demodulating unit, and data processor to extract and process DSM-CC objects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If VSB transmission mode is used for digital broadcasting, then compatibility with existing receivers is maintained, but receiving performance deteriorates in poor channel environments with frequent channel changes and noise
Solution Approach 1:
The patent applies preliminary action by inserting known data sequences into the transmitted signal before transmission. These known sequences are placed in advance in the signal stream, allowing the receiver to perform channel estimation and equalization operations. This pre-insertion of reference data enables the system to compensate for channel effects before they degrade the actual service data, thereby improving receiving performance in mobile and portable receivers without changing the VSB modulation scheme.
2Reliability
If additional encoding is performed on mobile service data, then error correction capability is improved, but data transmission rate decreases
Solution Approach 1:
The patent applies partial action by performing additional encoding operations selectively only on mobile service data packets, not on all transmitted data. The known data sequences are inserted without requiring additional encoding, and main service data continues to use standard encoding. This selective application of additional encoding to only the mobile service portion allows improved error correction for mobile data while minimizing the impact on overall transmission rate.
3Measurement precision
If known data sequences are inserted in data regions, then channel estimation accuracy is improved, but available data transmission capacity is reduced
Solution Approach 1:
The patent applies local quality by inserting known data sequences in specific local regions of the signal structure rather than uniformly throughout. The known sequences are placed in designated positions within the data stream where they can provide effective channel estimation without occupying excessive bandwidth. This localized insertion strategy provides sufficient reference points for accurate channel estimation while minimizing the reduction in overall data transmission capacity.
Data Source
AI summary
A method of transmitting a broadcast signal includes encoding mobile data for FEC (Forward Error Correction); encoding signaling information for signaling the mobile data; allocating the encoded mobile data and signaling data into a transmission frame; and transmitting the broadcast signal including the transmission frame, wherein the transmission frame includes a service signaling table having service_type information identifying a type of a service of the mobile data and hidden information indicating whether the service of the mobile data is hidden or not.