Digital Broadcast Receiver Channel Equalization for Mobile Service Data
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 for channel equalization, and using cubic spline interpolation or extrapolation to estimate channel impulse responses, allowing for effective channel-equalization and error correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If VSB transmission mode is used for digital broadcasting, then the system is simple and compatible with existing standards, but receiving performance deteriorates in poor channel environments with portable and mobile receivers
Solution Approach 1:
The patent applies preliminary action by inserting known training sequences and performing channel estimation before actual data transmission. The receiving system uses these pre-inserted training sequences to estimate channel characteristics and perform equalization in advance, enabling the system to compensate for channel changes and noise effects before they degrade the received signal quality.
Solution Approach 2:
The patent introduces channel estimation and equalization techniques as intermediary processes between the VSB transmission and reception. By inserting known training sequences as intermediaries, the system can measure channel characteristics and apply compensation algorithms, serving as a mediator that bridges the gap between the simple VSB modulation and the need for robustness against channel impairments.
2Reliability
If additional encoding is performed on mobile service data, then receiving performance is enhanced, but device complexity increases
Solution Approach 1:
The patent applies partial action by performing additional encoding only on mobile service data packets, not on all broadcast data. The system selectively applies channel estimation and equalization processing to mobile service data portions, providing enhanced protection where needed while avoiding unnecessary complexity for other data types. This selective approach balances performance enhancement with complexity management.
Data Source
AI summary
An apparatus and method for transmitting digital broadcast signal are provided. The apparatus includes a group formatter to format a data group including mobile service data, where the group formatter further maps the mobile service data into a data group of interleaved format, adds N training sequences into a corresponding location of the data group of interleaved format, adds signaling data into the data group of interleaved format, inserts place holder bytes for MPEG header and non-systematic Reed-Solomon (RS) parity into the data group of interleaved format, and deinterleaves the mobile service data in the data group of interleaved format, a non-systematic RS encoder to non-systematic RS encode the mobile service data in the formatted data group and insert non-systematic RS parity obtained from the non-systematic RS encoding into the formatted data group.