Adaptive Code Block Arrangement for Multicarrier Signal Error Correction
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Solution Overview
Problem
Existing multicarrier communication systems face challenges in maintaining error correction performance due to variations in Signal-to-Noise Ratio (SNR) across symbols in OFDM signals, especially in mobile communication systems, where frequency selective fading and multipath interference cause significant fluctuations in reception quality.
Innovation Solution
A multicarrier communication method and apparatus that analyzes the reception state of multicarrier signals based on Doppler frequency and delay profile, and adjusts the arrangement of code blocks in both time and frequency axes to minimize SNR variations, optimizing code block size and distribution according to the reception state for improved error correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If code blocks are arranged two-dimensionally in time and frequency axes to improve error correction performance, then reception performance improves, but the system becomes vulnerable to SNR variations caused by frequency selective fading and multipath interference
Solution Approach 1:
The patent applies dynamics by making the code block arrangement adaptive rather than fixed. The transmission apparatus dynamically adjusts the arrangement pattern of code blocks in the time-frequency grid based on channel conditions feedback from the reception apparatus. This allows the system to optimize error correction performance while adapting to varying SNR conditions caused by frequency selective fading and multipath interference.
Solution Approach 2:
The patent changes the parameter of code block arrangement configuration based on channel conditions. By modifying how code blocks are distributed across time and frequency resources according to measured channel quality, the system achieves better error correction performance while mitigating the harmful effects of SNR variations in specific time-frequency regions.
2Reliability
If spreading chips are arranged two-dimensionally in time and frequency to reduce inter-code interference, then orthogonality between spreading codes is maintained, but this approach cannot be applied to multicarrier communications that do not use spreading chips
Solution Approach 1:
The patent creates a universal error correction approach that works for both CDMA and non-CDMA multicarrier systems. Instead of relying on spreading chip arrangements specific to CDMA, the invention uses code block arrangement in the time-frequency grid, which is applicable to any multicarrier communication system regardless of whether spreading codes are used. This achieves the same goal of reducing interference while being universally applicable.
Solution Approach 2:
The patent extracts the essential function of two-dimensional arrangement (reducing interference through spatial distribution) from the CDMA-specific spreading chip context and applies it to the more general code block level in multicarrier systems. This separation allows the beneficial arrangement strategy to be used independently of the spreading code mechanism.
3Reliability
If error correcting coding is applied to multicarrier signals, then error rate decreases with reduced variation in reception quality, but SNR variations per symbol due to fading and multipath still cause performance deterioration
Solution Approach 1:
The patent applies local quality by ensuring that each code block experiences relatively uniform channel conditions through careful arrangement in the time-frequency grid. By distributing code blocks and controlling their placement, the system minimizes the impact of local SNR variations within each code block, allowing error correcting codes to work more effectively even in the presence of overall channel variations.
Data Source
AI summary
A multicarrier communication method and a multicarrier communication apparatus used for the method for adjusting the arrangement in code block units according to the actual reception state of the multicarrier signal, when arranging code blocks generated through error correcting coding processing not only in the time axis direction but also in the frequency axis direction in order to improve an error correction rate of a multicarrier signal.