OFDM Broadcast Signal Interleaving for Robust Mobile Reception
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Solution Overview
Problem
Current digital broadcast systems face challenges in data transmission efficiency, robustness, and network flexibility, particularly in handling large amounts of data and ensuring reliable mobile reception.
Innovation Solution
The method involves encoding service data, mapping it into OFDM symbols, frequency interleaving using a variable interleaving seed based on cyclic shifting and FFT size, and modulating the data for transmission, allowing multiple services to be transmitted through the same RF signal bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If digital broadcast signals transmit large amounts of video/audio data and additional data, then service quality and functionality are improved, but data transmission efficiency and network robustness deteriorate
Solution Approach 1:
The patent segments data into multiple transport streams with different priorities and service types. Each transport stream is independently encoded and transmitted, allowing efficient resource allocation and maintaining transmission efficiency even when carrying large amounts of diverse data content including video, audio, and additional services.
Solution Approach 2:
The patent implements a nested structure where transport streams are multiplexed within frames, which are further organized into super-frames. This hierarchical nesting allows efficient packaging and transmission of large amounts of data while maintaining organizational structure and transmission efficiency through standardized processing at each level.
2Adaptability or versatility
If digital broadcast signals include various types of additional data, then service functionality is improved, but transmission robustness deteriorates
Solution Approach 1:
The patent applies different encoding schemes, error correction levels, and transmission parameters to different transport streams based on their specific requirements. Critical services receive enhanced protection and optimized transmission parameters, while less critical additional data uses standard parameters, thereby maintaining overall robustness while supporting diverse service functionalities.
3Manufacturing precision
If broadcast system provides HD images and multi-channel audio, then service quality is improved, but data transmission efficiency deteriorates
Solution Approach 1:
The patent employs dynamic resource allocation where transmission parameters, coding rates, and bandwidth allocation are adjusted in real-time based on channel conditions and service requirements. This allows high-quality HD and multi-channel audio transmission while optimizing data transmission efficiency by adapting to varying conditions and prioritizing critical services.
4Adaptability or versatility
If network supports mobile reception equipment, then adaptability is improved, but transmission robustness deteriorates
Solution Approach 1:
The patent changes transmission parameters including modulation schemes, coding rates, and frame structures based on detected reception conditions. For mobile reception, the system dynamically adjusts parameters to maintain robustness despite movement-induced signal variations, while still supporting diverse service types through parameter adaptation.
Data Source
AI summary
A method and an apparatus for transmitting broadcast signals thereof are disclosed. The apparatus for transmitting broadcast signals comprises an encoder for encoding service data, a mapper for mapping the encoded service data into a plurality of OFDM (Orthogonal Frequency Division Multiplex) symbols to build at least one signal frame, a frequency interleaver for frequency interleaving data in the at least one signal frame by using a different interleaving-seed which is used for every OFDM symbol pair comprised of two sequential OFDM symbols, a modulator for modulating the frequency interleaved data by an OFDM scheme and a transmitter for transmitting the broadcast signals having the modulated data, wherein the different interleaving-seed is generated based on a cyclic shifting value and wherein an interleaving seed is variable based on an FFT size of the modulating.