Adaptive Uplink Link Adaptation via Subframe Segmentation
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Solution Overview
Problem
Current wireless communication systems face challenges in efficiently performing adaptive uplink link adaptation, particularly in managing varying channel conditions and differentiating between subframes with and without sounding reference signals (SRS), which affects block error rate (BLER) and overall system performance.
Innovation Solution
Implementing separate block error rate (BLER) filtering and outer loop link adaptation for subsets of subframes based on characteristics, such as the presence of SRS, to dynamically adjust modulation and coding schemes and resource blocks, thereby optimizing link adaptation for each subframe type.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If separate BLER filtering and outer loop link adaptation are implemented for subsets of subframes based on SRS presence, then uplink performance and throughput are improved, but system complexity increases
Solution Approach 1:
The patent segments the uplink subframes into two distinct subsets: subframes containing sounding reference signals (SRS) and subframes without SRS. Separate BLER filtering and outer loop link adaptation processes are independently implemented for each subset. This segmentation allows the system to apply optimized link adaptation parameters specific to each subframe type, improving overall uplink throughput by addressing the different channel estimation conditions and error characteristics of SRS-containing and SRS-free subframes.
2Reliability
If link adaptation parameters are dynamically adjusted for different subframe types, then block error rate is reduced, but processing overhead increases
Solution Approach 1:
The patent applies local quality by implementing distinct BLER filtering and link adaptation strategies tailored to each subframe subset. For SRS-containing subframes, one set of adaptation parameters is used, while for SRS-free subframes, a different set is applied. This localized approach reduces the block error rate by matching the link adaptation characteristics to the specific channel conditions of each subframe type, rather than using a uniform approach for all subframes.
3Measurement precision
If multiple separate BLER filtering processes are maintained for different subframe subsets, then link adaptation accuracy is improved, but memory and computational resources are consumed
Solution Approach 1:
The patent divides the link adaptation process into separate segments for SRS-containing and SRS-free subframes, with independent BLER filtering maintained for each segment. This segmentation improves link adaptation accuracy by preventing error rate mixing between different subframe types, allowing each subset to be optimized independently. The separate filtering processes enable more precise tracking of block error characteristics specific to each subframe category.
Data Source
AI summary
A wireless communication system is presented for adaptive uplink (UL) link adaptation (LA). The adaptive UL LA can include multiple outer loops, for which multiple block error rate (BLER) filtering is performed. Each of the multiple BLER filtering can be performed on groups or sub-groups of subframes, in which each group has the same or similar coding characteristics. For example, one group in TD-LTE could be subframes with sounding reference signal (SRS) and another group could be subframes without SRS. Each of the multiple BLER filtering can use the same or different BLER algorithm, BLER target and/or BLER parameters.