Broadcast Transport Stream Formatting With SRS for VSB Equalization
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Solution Overview
Problem
The existing ATSC VSB digital terrestrial broadcasting system experiences deteriorated receiving performance in multi-path fading and Doppler fading channel environments due to the low frequency of the field sync signal, making it difficult for the equalizer to estimate and correct channel distortions effectively.
Innovation Solution
A method for formatting digital broadcast transport stream packets by inserting a known supplementary reference sequence (SRS) into the adaptation field of the packet, which is used for synchronization and channel equalization, maintaining compatibility with existing systems by leveraging existing standards and mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the field sync signal frequency is kept low to maintain compatibility with existing ATSC VSB standards, then system compatibility is preserved, but receiving performance deteriorates in multi-path fading and Doppler fading channel environments
Solution Approach 1:
The patent divides the synchronization function into two parts: the original field sync signal for basic synchronization and a new supplementary reference sequence (SRS) for enhanced equalization. This segmentation allows each component to serve its specific purpose optimally while maintaining overall system compatibility.
Solution Approach 2:
The supplementary reference sequence (SRS) acts as an intermediary element inserted into the transport stream to bridge the gap between existing system compatibility requirements and the need for improved receiving performance. The SRS provides additional known data that helps equalizers operate effectively without disrupting the existing field sync signal structure.
2Reliability
If additional synchronization data is inserted into the transport stream to improve equalization performance, then receiving performance in inferior channel environments improves, but system complexity increases
Solution Approach 1:
The supplementary reference sequence (SRS) structure is designed to be universal and compatible with existing ATSC VSB system components. It leverages existing randomization, interleaving, and modulation mechanisms, requiring no new hardware or fundamental system changes, thus adding minimal complexity while providing enhanced functionality.
Solution Approach 2:
The patent modifies specific parameters of the transport stream (inserting known data sequences at defined positions) rather than changing the fundamental system architecture. This parameter-based approach allows performance improvement through configuration changes rather than structural complexity increases.
3Adaptability or versatility
If the adaptation field is used to insert supplementary reference sequence data, then compatibility with existing MPEG-2 transport stream structure is maintained, but the available space for SRS insertion is limited
Solution Approach 1:
The patent utilizes the adaptation field partially, inserting SRS data only where needed rather than filling the entire field. This partial action approach maintains compatibility while providing sufficient known data for equalization without requiring excessive space that would disrupt the transport stream structure.
Data Source
AI summary
A method of formatting a digital broadcast transport stream packet, a digital broadcast transmitter, and a signal processing method thereof, includes constructing a transport stream packet that includes a stuffing region for an insertion of a known supplementary reference signal (SRS) data therein, randomizing the packet that includes the stuffing region is randomized, and the SRS data is inserted into the stuffing region of the randomized packet. Adding a parity for an error correction to the packet into which the SRS data has been inserted, the packet to which the parity has been added is interleaved, and a trellis encoding of the interleaved packet is performed. Inserting a segment sync signal and a field sync signal into the trellis-encoded packet, and a vestigial side band (VSB) modulation and an RF conversion of the packet are performed to transmit the VSB-modulated and RF-converted packet.