Digital Broadcasting System Mobile Data Encoding
Find Innovative SolutionsGenerate Solutions
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 enhances receiving performance by performing additional encoding on mobile service data, inserting known data in predetermined regions, and multiplexing mobile and main service data, while also supporting IP-based mobile service data transmission.
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 scenarios
Solution Approach 1:
The transmission system is segmented into multiple carriers (OFDM structure) instead of using a single carrier VSB method. This divides the broadcast signal into numerous orthogonal frequency subcarriers, allowing the system to maintain compatibility while improving resistance to channel changes and noise through frequency diversity.
Solution Approach 2:
The patent changes the fundamental transmission parameter from single-carrier VSB modulation to multi-carrier OFDM modulation. This parameter change enables the system to achieve better receiving performance in mobile and poor channel environments while maintaining standard compatibility through proper framing and synchronization signals.
2Reliability
If additional encoding is performed on mobile service data, then resistance to channel changes and noise improves, but device complexity increases
Solution Approach 1:
Error correction codes are applied in advance to mobile service data packets before transmission. This preliminary encoding action protects the data against channel changes and noise, allowing the receiver to reliably decode mobile services even in challenging conditions without requiring complex real-time processing.
Solution Approach 2:
The patent introduces intermediate processing stages including error correction encoding, packetization, and multiplexing layers between the source data and the physical transmission medium. These intermediary components systematically enhance reliability while managing complexity through modular design.
3Reliability
If known data is inserted in predetermined regions, then receiving performance and channel estimation accuracy improve, but loss of information increases due to overhead
Solution Approach 1:
Known data sequences (pilot signals) are inserted in predetermined regions of the OFDM frame structure before transmission. This preliminary placement of reference signals enables the receiver to perform accurate channel estimation and equalization, improving receiving performance while the overhead is managed through efficient pilot placement strategies.
Data Source
AI summary
A digital broadcasting system and a method of processing data are disclosed, which are robust to error when mobile service data are transmitted. To this end, additional encoding is performed for the mobile service data, whereby it is possible to strongly cope with fast channel change while giving robustness to the mobile service data.