Proxy Acknowledgement Feedback for Low Error Rate Convergence
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems, achieving outer-loop feedback convergence for low error rates, particularly in ultra-reliable low latency communications (URLLC), is challenging due to insufficient NACK feedback, which prevents the adjustment of transmission parameters to reach target block error rates (BLER) efficiently.
Innovation Solution
Implementing a proxy ACK/NACK feedback mechanism that uses a higher BLER for additional transmissions or partial decoding, allowing the base station to adjust outer-loop feedback parameters based on ACK/NACK feedback from these transmissions, thereby facilitating convergence to the target low BLER.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If outer-loop feedback is used with a low target error rate (e.g., BLER < 1%), then reliability is improved, but convergence speed deteriorates due to insufficient NACK feedback
Solution Approach 1:
The patent introduces a proxy ACK feedback mechanism that acts as an intermediary to provide additional feedback information. The proxy ACK is generated based on partial decoding (using only a subset of LLRs or fewer iterations) and serves as a mediator between the low target BLER communications and the outer-loop feedback convergence process, enabling faster adaptation without compromising the actual transmission reliability
Solution Approach 2:
The patent applies partial action by performing partial decoding of the received communications - using only a subset of log-likelihood ratios (LLRs) or fewer decoding iterations than required for full decoding. This partial processing generates proxy ACK feedback that accelerates outer-loop convergence while the full decoding is still performed to ensure the target low BLER is met
2Loss of time
If partial decoding with fewer LLRs is performed for proxy ACK feedback, then convergence speed is improved, but measurement precision deteriorates
Solution Approach 1:
The patent performs partial decoding by using only a subset of LLRs or fewer iterations to generate the proxy ACK feedback. This partial action provides sufficient information for outer-loop convergence while avoiding the need to process all LLRs, thus balancing speed and accuracy requirements
Solution Approach 2:
The patent segments the decoding process into two distinct parts: (1) partial decoding using a subset of LLRs or fewer iterations to generate proxy ACK feedback for fast convergence, and (2) full decoding using all LLRs and complete iterations to ensure the target low BLER is achieved. This segmentation allows each part to serve its specific purpose optimally
3Loss of information
If additional transmissions are performed for proxy feedback, then feedback availability is improved, but productivity deteriorates due to increased transmission overhead
Solution Approach 1:
The patent makes the existing additional transmissions (introduced for other purposes such as diversity or robustness) serve a dual function: they carry both the primary communication data and enable the generation of proxy ACK feedback for outer-loop convergence. This multi-functionality avoids the need for separate dedicated feedback transmissions, thus improving feedback availability without proportionally increasing overhead
Data Source
AI summary
Methods, systems, and devices for wireless communications are described which may enable a user equipment (UE) and a base station to use outer-loop feedback support to reach a desired error rate for low latency communications. For example, a base station may transmit a proxy acknowledgement feedback configuration to a UE for communications associated with a low target error rate. In some cases, after receiving the communications from the base station, the UE may receive secondary communications from the base station. The UE may then decode the first and/or second communications according to the proxy acknowledgement feedback configuration and/or a normal acknowledgement feedback configuration and may determine a proxy acknowledgement feedback based on the decoding. Further, the UE may transmit the proxy and/or normal acknowledgement feedback to the base station, which may update outer-loop power settings for the low latency communications based on the acknowledgement feedback.