OFDM Broadcast Signal Framing 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, especially for mobile reception and indoor environments, due to the large amounts of video/audio data and additional services they need to handle.
Innovation Solution
The method involves encoding service data, bit interleaving, and mapping it into OFDM symbols for modulation, allowing for transmission of multiple broadcast services through the same RF signal bandwidth using MIMO systems, ensuring robust and efficient data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If digital broadcast systems transmit large amounts of video/audio data and additional services, then service functionality is improved, but data transmission efficiency deteriorates
Solution Approach 1:
The patent segments broadcast data into multiple data pipes, each carrying different types of service data (video, audio, additional services). This segmentation allows independent optimization of each data pipe's transmission parameters, improving overall transmission efficiency while maintaining diverse service functionality.
Solution Approach 2:
The patent introduces time-domain multiplexing as an additional dimension for data transmission. By transmitting different service data in different time slots within the same RF bandwidth, the system achieves both high service functionality and efficient spectrum utilization.
2Adaptability or versatility
If digital broadcast systems handle large amounts of data, then service diversity is improved, but transmission robustness deteriorates
Solution Approach 1:
The patent applies different coding and modulation schemes to different data pipes based on their specific requirements. Critical services receive more robust coding, while less critical services use more efficient but less robust schemes, achieving both service diversity and transmission robustness.
Solution Approach 2:
The patent implements forward error correction coding before data transmission. This preliminary protection mechanism adds redundancy to the data streams, cushioning against transmission errors and improving robustness without significantly reducing service diversity.
3Adaptability or versatility
If digital broadcast systems support mobile reception equipment, then network flexibility is improved, but reception reliability deteriorates
Solution Approach 1:
The patent implements dynamic adaptation of transmission parameters based on channel conditions. The system continuously monitors reception quality and adjusts coding rates, modulation schemes, and data pipe allocations in real-time, maintaining both network flexibility for mobile devices and reception reliability under varying conditions.
Data Source
AI summary
The present invention provides an apparatus of transmitting broadcast signals. The apparatus includes, an encoder for encoding service data, a bit interleaver for bit interleaving the encoded service data, a mapper for mapping the bit interleaved service data into a plurality of OFDM (Orthogonal Frequency Division Multiplex) symbols to build at least one signal frame, an OFDM modulator for modulating data in the built at least one signal frame by an OFDM scheme and a transmitter for transmitting the broadcast signals having the modulated data.