Configurable Block Interleaving for Time and Frequency Diversity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current power line communication technologies face challenges in efficiently decoding signals in noisy channels, achieving time and frequency diversity, removing signal interference, maintaining signal levels, and measuring channel quality for high transmission rates, especially in broadband applications.
Innovation Solution
A method and apparatus for data interleaving using a demultiplexer to split input packets into sub-packets, flipping blocks to modify some sub-packets, and sub-interleavers to interleave them, followed by concatenation to form output packets, within a system employing Orthogonal Frequency Division Multiplexing (OFDM) and Differential Binary Phase Shift Keying (DBPSK) for robust data transmission over power lines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If broadband technologies are applied in PLC, then high speed data transmission is achieved, but signal robustness in noisy channels deteriorates
Solution Approach 1:
The patent divides the data stream into multiple segments and applies different interleaving strategies (block interleaving for frequency diversity, convolutional interleaving for time diversity) to separate segments. This segmentation allows the system to maintain high transmission rates while protecting different portions of data with appropriate error correction mechanisms, resolving the contradiction between speed and reliability.
Solution Approach 2:
The patent dynamically adjusts interleaving depth and error correction code rates based on channel conditions. When noise levels increase, the system increases interleaving depth and error correction overhead, thereby maintaining signal robustness without permanently reducing transmission rate, effectively resolving the speed-reliability tradeoff.
2Reliability
If signal interleaving is applied to achieve time and frequency diversity, then signal robustness is improved, but device complexity increases
Solution Approach 1:
The patent separates the interleaving function into distinct block interleavers and convolutional interleavers that operate on different dimensions (frequency and time). This modular segmentation makes the complex diversity achievement more manageable and implementable, reducing overall system complexity while maintaining robustness.
Solution Approach 2:
The patent combines block interleaving and convolutional interleaving in a unified framework where they work together to provide both frequency and time diversity. By merging these techniques, the system achieves comprehensive signal robustness without requiring completely separate complex systems, thereby managing device complexity effectively.
3Reliability
If error correction coding is increased to remove signal interference, then signal quality is improved, but transmission efficiency deteriorates
Solution Approach 1:
The patent applies error correction coding selectively rather than uniformly to all data. By using partial redundancy and adaptive code rates, the system provides sufficient error correction for critical data portions while maintaining higher efficiency for less critical portions, thus improving signal quality without excessively reducing transmission efficiency.
Solution Approach 2:
The patent dynamically adjusts error correction code rates and interleaving depths based on channel conditions and data priority. This parameter adaptation allows the system to optimize the balance between signal quality and transmission efficiency, applying stronger error correction only when and where needed, thereby maintaining high overall transmission efficiency while improving signal quality.
Data Source
AI summary
An embodiment is a method and apparatus to interleave data. A demultiplexer demultiplexes an input packet having N bits into L sub-packets on L branches. M flipping blocks flip M of the L sub-packets. M is smaller than L. L sub-interleavers interleave the (L-M) sub-packets and the M flipped sub-packets. A concatenator concatenates the interleaved sub-packets to form an output packet.