Preamble Symbol Receiving Method for DVB-T2
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Solution Overview
Problem
The existing DVB_T2 standard's time-domain structure for preamble symbols fails in coherent detection in complex frequency selective fading channels, leading to failures in DBPSK differential decoding and degraded frequency-domain channel estimation performance.
Innovation Solution
A preamble symbol receiving method and device that utilize a free combination of three-segment structures, including time-domain main body signals, prefixes, and postfixes or hyper prefixes, for initial timing synchronization, integer and fractional frequency offset estimation, and channel estimation, enabling coherent detection and robust signaling information extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the existing DVB_T2 standard time-domain structure is used for preamble symbols, then the structure is simple and easy to implement, but coherent detection fails in complex frequency selective fading channels and DBPSK differential decoding fails
Solution Approach 1:
The preamble symbol is divided into three distinct segments: a time-domain main body signal, a prefix generated from the main body signal, and a postfix or hyper prefix generated from the main body signal. This segmentation allows each part to serve specific functions - the main body for coherent detection, the prefix for timing synchronization, and the postfix for frequency offset estimation - thereby resolving the contradiction between structural simplicity and detection reliability in frequency selective fading channels
Solution Approach 2:
The invention creates a composite preamble structure combining multiple signal types (main body signal, prefix, postfix) with different properties. The time-domain main body signal provides coherence for detection, while the prefix and postfix provide robustness against frequency offsets and multi-path effects. This composite structure maintains implementation simplicity while achieving reliable detection in challenging channel conditions
2Ease of manufacture
If the DVB_T2 standard preamble structure is used, then implementation is straightforward, but frequency-domain channel estimation performance is severely degraded in long multi-path channels
Solution Approach 1:
The prefix is generated in advance from the time-domain main body signal and placed before it in the preamble structure. This preliminary action creates a known reference signal that arrives earlier in the channel, allowing the receiver to perform timing synchronization and channel estimation before processing the main body signal, thereby improving channel estimation precision without complicating the overall implementation
Solution Approach 2:
The prefix acts as an intermediary element between the transmitter and receiver, providing a known reference signal that mediates the channel estimation process. By using this intermediate reference signal, the receiver can accurately estimate channel characteristics in frequency-selective fading conditions without requiring complex implementation procedures
3Productivity
If rough timing synchronization is performed in long multi-path channels, then processing is faster and simpler, but great deviation occurs leading to mistakes in integer frequency offset estimation
Solution Approach 1:
The prefix is placed before the main body signal in the time domain, allowing the receiver to perform timing synchronization using this preliminary reference signal before processing the main signal. This preliminary timing acquisition provides an accurate starting point for frequency offset estimation, enabling both fast processing and high precision by avoiding the need for iterative refinement
Solution Approach 2:
The invention replaces complex iterative timing and frequency synchronization algorithms with a simpler structure-based approach. The predefined three-segment structure with generated prefix and postfix allows the receiver to directly identify timing and frequency parameters from the signal structure itself, substituting mechanical search algorithms with structure-based detection that achieves both speed and precision
Data Source
AI summary
A preamble symbol receiving method includes, receiving a signal, processing the received signal, determining whether the processed signal contains the preamble symbol, in response to determining that the processed signal contains the preamble symbol, determining the position of the preamble symbol and resolving signaling information carried by the preamble symbol. The preamble symbol includes at least one time-domain symbol generated using a free combination of any number of first three-segment structures and second three-segment structures according to a predefined generation rule.