LTE De-Rate Matching with Pre-LLR Combining and NULL Bypass
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Solution Overview
Problem
Current communication systems in E-UTRAN lack efficient de-rate matching mechanisms, particularly in handling NULL bits and LLR combining, leading to high processing and memory burdens, especially when the code rate is near 1.
Innovation Solution
The proposed solution simplifies the de-rate matching stage by moving LLR combining before de-rate matching, exploiting the feature of F=0 in the 8.4.0 specification version, and splitting the de-rate matching process into NULL insertion, stream separation, and de-interleaving stages, allowing for efficient NULL bypassing and reduced memory throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If de-rate matching is implemented with LLR combining after the process, then accurate data transmission is ensured, but processing resource usage and memory throughput requirements increase significantly
Solution Approach 1:
The patent applies preliminary action by performing LLR combining before de-rate matching instead of after. This reordering allows the combining operation to work with fewer bits and reduces the memory throughput requirements, while still achieving accurate data transmission through the subsequent de-rate matching process
2Reliability
If de-rate matching processes all bits including NULL bits, then complete data reconstruction is achieved, but memory throughput and processing burden increase
Solution Approach 1:
The patent extracts and removes NULL bits from the de-rate matching process. By identifying and eliminating these unnecessary bits before processing, the system achieves complete data reconstruction without the computational burden of processing filler data, thereby reducing memory throughput requirements and processing complexity
3Productivity
If code rate is near 1, then transmission efficiency is improved, but de-rate matching becomes computationally intensive
Solution Approach 1:
When code rate is near 1, the patent extracts and removes NULL bits from processing. This extraction is particularly effective in high code rate scenarios where the number of actual data bits is close to the total transmitted bits, significantly reducing the computational intensity and energy consumption of de-rate matching while maintaining transmission efficiency
Data Source
AI summary
Embodiments of the invention provide a method of de-rate matching without NULL bits skipping. Date is received without NULLs and inputted into a LLR combining block. The history data without NULLs is buffered. Log-likelihood ratio (LLR) combining is called before de-rate matching. The output of LLR combining is de-interleaved. The reading pointer is offset to forge NULLs. Finally, de-interleaving output without NULLs is sent to a turbo decoder.