OFDM Broadcast Signal Framing With Repeated L1 Preamble Blocks
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Solution Overview
Problem
The increasing demand for higher data capacity and number of broadcasting channels in digital broadcasting technologies, such as DVB-C2, poses challenges in efficiently transmitting and receiving signals with improved data transmission efficiency.
Innovation Solution
The method involves mapping preamble and data bits into symbols, building data slices, and modulating signal frames using Orthogonal Frequency Division Multiplexing (OFDM), with shortened and punctured LDPC decoding for reception, allowing for efficient transmission and reception of broadcasting signals by dividing preamble data symbols into Layer 1 blocks corresponding to active subcarriers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If more broadcasting channels and data services are transmitted, then data capacity increases, but signaling overhead increases
Solution Approach 1:
The patent segments the transmission system into distinct functional blocks: preamble data symbols are separated from data symbols, and further divided into L1 blocks. This segmentation allows independent processing and optimization of signaling information, reducing the overhead required for transmitting control data while maintaining high data capacity.
Solution Approach 2:
The patent introduces a new dimensional organization by dividing preamble data symbols into multiple L1 blocks along the frequency domain, where each L1 block corresponds to a specific bandwidth range. This dimensional change allows parallel transmission of multiple channels with reduced signaling overhead per channel.
2Quantity of substance
If more broadcasting channels are transmitted with same energy, then channel capacity increases, but noise robustness deteriorates
Solution Approach 1:
By segmenting the spectrum into multiple L1 blocks and assigning each to different channels, the patent enables independent error correction processing for each channel. The shortened and punctured LDPC decoding scheme operates on each L1 block separately, maintaining noise robustness even as channel capacity increases.
Solution Approach 2:
The patent applies different decoding strategies (shortened and punctured LDPC) tailored to specific L1 blocks based on their channel conditions. This local optimization ensures that each channel maintains adequate noise robustness while contributing to overall increased channel capacity.
Data Source
AI summary
A method of transmitting a broadcasting signal is provided. The method includes encoding data; encoding signaling data by an LDPC (Low Density Parity Check) scheme; building a signal frame based on at least one preamble data symbol having the encoded signaling data and a data slice having the encoded data; inserting at least one pilot into the signal frame with a specific pattern and modulating the signal frame by an OFDM (Orthogonal Frequency Division Multiplexing) method; and transmitting the modulated signal frame. A signaling block having the signaling data is repeated in the at least one preamble data symbol in a frequency domain by a bandwidth. The band width of the signaling block corresponds to a number of active subcarriers assigned to a single channel.