OFDM Broadcast Signal Interleaving for Robust Multi-Service Transmission
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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 larger amounts of video/audio data and additional services, then service capability is improved, but data transmission efficiency deteriorates
Solution Approach 1:
The patent segments data into multiple data pipes, each carrying different types of broadcast data (video, audio, additional services). This segmentation allows efficient multiplexing and transmission of large amounts of data through organized channels, resolving the contradiction between data quantity and transmission efficiency.
Solution Approach 2:
The patent introduces time-domain multiplexing as an additional dimension for data transmission. By transmitting multiple services in different time slots within the same RF bandwidth, the system achieves efficient transmission of large data volumes without sacrificing transmission efficiency.
2Quantity of substance
If digital broadcast system provides HD images, multi-channel audio and additional services, then service capability is improved, but robustness of transmission/reception networks deteriorates
Solution Approach 1:
The patent applies different modulation and coding schemes to different data pipes based on their specific requirements. Critical services receive more robust encoding, while less critical data uses more efficient schemes. This local differentiation maintains network robustness while supporting diverse service data volumes.
Solution Approach 2:
The system dynamically adjusts transmission parameters (modulation order, coding rate, time slot allocation) for different data pipes based on channel conditions and service requirements. This adaptability ensures robust transmission of service data while maintaining overall network reliability.
3Quantity of substance
If digital broadcast system provides additional services, then service capability is improved, but network flexibility deteriorates
Solution Approach 1:
The patent implements dynamic resource allocation where data pipes can be created, modified, or removed based on service requirements. The system can flexibly adjust the number and characteristics of data pipes to accommodate different combinations of additional services, maintaining network flexibility while supporting diverse data types.
Solution Approach 2:
The data pipe architecture provides a universal framework that can carry various types of broadcast data (video, audio, text, interactive services) through the same transmission infrastructure. This multi-functional approach enables the system to provide additional services while maintaining network flexibility.
4Productivity
If multiple services are transmitted through the same RF signal bandwidth, then spectrum efficiency is improved, but interference between services increases
Solution Approach 1:
The patent segments the RF bandwidth into multiple orthogonal frequency subcarriers and time slots, creating separate transmission channels for different services. This segmentation reduces inter-service interference while maintaining high spectrum efficiency through dense packing of transmission resources.
Solution Approach 2:
The OFDM modulation scheme acts as an intermediary that separates different services into orthogonal frequency domains. This mathematical transformation ensures that services transmitted in the same RF bandwidth do not interfere with each other, enabling efficient spectrum utilization.
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.