Broadcast Signal Framing for MIMO-OFDM Compatibility and Robust Reception
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Solution Overview
Problem
Digital broadcast systems face challenges in enhancing data transmission efficiency and maintaining compatibility with conventional methods, particularly in robustness and flexibility, especially in mobile and indoor reception environments.
Innovation Solution
The implementation of a MIMO (Multi-Input Multi-Output) system in digital broadcast transmission, which includes a broadcast signal transmitter and receiver that use Bit Interleaved Coded Modulation (BICM) and Orthogonal Frequency-Division Multiplexing (OFDM) to enhance data transmission efficiency and robustness, while maintaining compatibility with conventional systems through scalable video coding (SVC) and additional frame structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a MIMO system is implemented to enhance data transmission efficiency, then data transmission efficiency is improved, but device complexity increases
Solution Approach 1:
The MIMO system is divided into multiple independent transmit antennas and receive antennas, each handling specific signal streams. The transmission system segments the data into multiple parallel channels, allowing independent processing and simplifying the overall system architecture while maintaining high transmission efficiency
Solution Approach 2:
The MIMO system is designed to support both MIMO and conventional SISO transmission modes within the same framework. The transmit and receive antennas can function universally for different transmission schemes, allowing the system to adapt to various channel conditions and device capabilities without requiring separate dedicated hardware for each mode
2Reliability
If MIMO processing is used to improve robustness in diverse broadcast environments, then reliability is improved, but device complexity increases
Solution Approach 1:
The system dynamically adapts between MIMO and SISO transmission modes based on channel conditions and receiver capabilities. The transmit side can switch transmission schemes in real-time, and the receive side can flexibly process signals according to the detected transmission mode, maintaining robustness while managing complexity through adaptive behavior rather than fixed complex architecture
Solution Approach 2:
A compatibility layer acts as an intermediary between the MIMO processing functions and the conventional broadcast reception infrastructure. This layer handles the complexity of MIMO signal processing while presenting a simplified interface to conventional receivers, allowing robustness benefits to be achieved without requiring all devices to implement full MIMO complexity
3Adaptability or versatility
If additional frame structures are implemented for MIMO compatibility, then adaptability is improved, but device complexity increases
Solution Approach 1:
The MIMO-specific frame structures are nested within the existing DVB-T2 frame format. MIMO data is embedded as additional fields or extensions within the conventional frame structure, allowing MIMO functionality to be added without replacing the entire frame architecture. Conventional receivers can ignore the nested MIMO portions while MIMO-capable receivers can extract and process them
Solution Approach 2:
Different parts of the frame structure are optimized for different functions: conventional fields maintain compatibility with existing receivers, while specific nested regions contain MIMO-specific information for enhanced receivers. This local differentiation allows the system to provide adaptability without requiring uniform complexity throughout the entire frame structure
Data Source
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AI summary
A method for transmitting broadcast signals, the method comprising: encoding data in Physical Layer Pipes, PLPs, and L1 signaling information, wherein the encoding further comprises a first encoding for PLPs for Multi-Input Single-Output, MISO, processing, a second encoding for PLPs for Multi-Input Multi-Output, MIMO, processing and a third encoding for the L1 signaling information for MISO processing, wherein the second encoding includes: Forward Error Correction, FEC, encoding data in each PLP for the MIMO processing; Quadrature Amplitude Modulation, QAM, mapping the FEC encoded data into two symbols; MIMO processing the mapped data; cell interleaving the MIMO processed data; and time interleaving the cell interleaved PLP data; building at least two signal frames by mapping the encoded data in the PLPs and the encoded L1 signaling information; pair-wise frequency interleaving data in the built at least two signal frame; and modulating the pair-wise frequency interleaved data in the at least two signal frames by an Orthogonal Frequency Division Multiplexing, OFDM, method; and transmitting two broadcast signals having the modulated data, wherein a signal frame includes a preamble and data symbols, wherein the modulating further includes inserting a P1 symbol and an AP1 symbol into the preamble, wherein the P1 symbol carrying a transmission type and a corresponding preamble identifier and the AP1 symbol carrying additional transmission parameters to detect a broadcast signal, wherein the P1 symbol includes a main part and two portions and the AP1 symbol includes an additional main part and two additional portions, wherein a length of each of the two additional portions in the AP1 symbol is different from a length of each of the two portions in the P1 symbol.