Mobile Service Data Encoding With Known Data for VSB Reception
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Solution Overview
Problem
Digital broadcast systems using the VSB transmission scheme face challenges in maintaining reception performance, especially for mobile receivers due to channel variations and noise, leading to deteriorated performance.
Innovation Solution
A digital broadcast system that encodes mobile service data and inserts known data recognized by both transmission and reception ends, improving reception performance by multiplexing and modulating the data with main service data, and using error-correction encoding and interleaving to enhance robustness against channel changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If VSB transmission scheme is used for mobile service data, then transmission compatibility is maintained, but reception performance deteriorates under poor channel conditions
Solution Approach 1:
The patent segments mobile service data from main service data by using separate ensembles and program table information. Mobile service data are assigned to specific ensembles (e.g., ensemble 0) with dedicated transmission parameters, allowing independent error correction and processing. This segmentation enables optimized reception for mobile conditions without affecting main service data transmission.
Solution Approach 2:
The patent changes transmission parameters specifically for mobile service data, including using different code rates, modulation schemes, and error correction codes compared to main service data. Program table information contains ensemble-specific parameters that allow the receiver to adjust decoding parameters based on the service type, improving reliability under varying channel conditions.
2Reliability
If additional encoding is applied to mobile service data, then reception performance improves, but system complexity increases
Solution Approach 1:
The patent uses a universal program table information structure that serves multiple functions: it identifies ensembles, specifies data types (main service vs. mobile service), provides error correction parameters, and enables demultiplexing. This multi-functional approach allows additional encoding for mobile services without requiring separate complex control mechanisms, managing system complexity through a unified information framework.
Solution Approach 2:
The patent performs preliminary encoding and error correction preparation for mobile service data before transmission by organizing them into specific ensembles with pre-configured parameters in the program table. Known data are inserted in advance at predetermined positions, allowing the receiver to prepare appropriate decoding parameters beforehand, reducing real-time processing complexity.
3Reliability
If known data are inserted into data zone, then reception stability improves, but data transmission efficiency decreases
Solution Approach 1:
The patent inserts known data at specific local positions within the data zone rather than uniformly throughout. Program table information specifies exact ensemble and packet positions for known data insertion, allowing error correction resources to be concentrated where most needed while minimizing impact on overall data transmission efficiency. This localized approach provides targeted reception stability without excessive overhead.
Data Source
AI summary
The present invention is directed to a digital broadcast system and a data processing method. A broadcast signal in which mobile service data and main service data are multiplexed is transmitted and received. Then, in a broadcasting receiver, the program table information including information about a service or a program of an ensemble is parsed according to an identifier of the ensemble in which the mobile service data are multiplexed, in the received broadcast signal. And a mobile service is outputted by using the mobile service data and the parsed program table information.