OFDM Channel Interleaving for Balanced Code Block Allocation
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Solution Overview
Problem
Existing communication systems face challenges in efficiently utilizing limited transmission resources, maximizing time and frequency diversity, and minimizing interference between code blocks in OFDM systems.
Innovation Solution
A method for resource allocation in OFDM systems, where a time and frequency resource block is divided into equal duration resource elements, with data blocks segmented into code blocks and assigned resources using specific indexing schemes to optimize resource distribution and minimize interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If data blocks are segmented into multiple code blocks with different sizes to maximize packing efficiency, then transmission resource utilization is improved, but interference between different code blocks increases
Solution Approach 1:
The patent segments data blocks into multiple code blocks of different sizes to maximize packing efficiency in transmission resources. Each code block is independently encoded and interleaved, allowing flexible adaptation to channel conditions while maintaining high resource utilization.
Solution Approach 2:
The patent applies different interleaving schemes to different code blocks based on their specific characteristics and positions. Code blocks experiencing deep fades receive enhanced interleaving protection, while others use standard schemes, optimizing performance locally without uniformly increasing interference.
2Device complexity
If code blocks are transmitted using standard interleaving schemes, then implementation complexity is reduced, but time and frequency diversity is not maximized
Solution Approach 1:
The patent introduces dynamic interleaving schemes that adapt to channel conditions. The interleaver depth and pattern are adjusted based on estimated channel quality, allowing the system to maximize time and frequency diversity when needed while maintaining simpler schemes when channel conditions are good.
Solution Approach 2:
The patent changes interleaving parameters such as interleaver depth, shift amount, and pattern based on channel conditions and code block characteristics. This allows optimization of diversity gain without requiring complete redesign of the interleaving structure, balancing complexity and performance.
3Ease of operation
If equal number of resource elements are assigned to all code blocks, then resource distribution is simplified, but code blocks experiencing deep fades receive insufficient protection
Solution Approach 1:
The patent assigns different numbers of resource elements to different code blocks based on their specific channel conditions. Code blocks that experience deep fades are allocated more resource elements and potentially more robust modulation schemes, while code blocks in good conditions use fewer resources with higher-order modulation.
Solution Approach 2:
The patent uses channel quality feedback to dynamically adjust resource element allocation among code blocks. The receiver measures channel conditions and feeds back information that allows the transmitter to optimize resource distribution, ensuring that code blocks in poor conditions receive enhanced protection.
Data Source
AI summary
A method and apparatus for channel interleaving in a wireless communication system. In one aspect of the present invention, the data resource elements are assigned to multiple code blocks, and the numbers of data resource elements assigned to each code block are substantially equal. In another aspect of the present invention, a time-domain-multiplexing-first (TDM-first) approach and a frequency-domain-multiplexing-first (FDM-first) approach are proposed. In the TDM-first approach, at least one of a plurality of code blocks are assigned with a number of consecutive data carrying OFDM symbols. In the FDM-first approach, at least one of the plurality of code blocks are assigned with all of the data carrying OFDM symbols. Either one of the TDM first approach and the FDM-first approach may be selected in dependence upon the number of the code blocks, or the transport block size, or the data rate.