Two-Part HARQ-ACK Compression for Uplink Resource Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireless communication systems face inefficiencies in resource allocation for hybrid automatic repeat request (HARQ) acknowledgment feedback, particularly in reducing the number of bits required for HARQ-ACK feedback in the physical uplink control channel (PUCCH), where techniques like HARQ-ACK feedback are unreliable and resource-intensive.
Innovation Solution
The implementation of a two-part HARQ-ACK compression method, where a first part indicates whether all received code blocks are successfully decoded, and a second part is sent only if necessary, using lossless or lossy compression techniques like bundling and partitioning to reduce overhead, with user equipment (UE) capability signaling and network configuration enabling or disabling this method based on codebook length and bundling size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional HARQ-ACK feedback is transmitted for all code blocks, then reliable error recovery is maintained, but the number of feedback bits increases consuming excessive uplink resources
Solution Approach 1:
The HARQ-ACK feedback is divided into two separate parts: Part 1 contains a compact indication (1-2 bits) representing the overall status of all code blocks (e.g., all ACK, all NACK, or mixed), while Part 2 contains the detailed per-code-block acknowledgment bits that are only fully transmitted when necessary. This segmentation allows the system to reduce feedback overhead by transmitting only Part 1 when all code blocks have the same status, while maintaining full reliability when mixed statuses occur.
Solution Approach 2:
Instead of always transmitting the complete HARQ-ACK feedback for all code blocks, the system transmits only a partial indication in Part 1 when the code block statuses are uniform (all ACK or all NACK). The full detailed feedback in Part 2 is transmitted only when necessary (when mixed statuses are detected). This partial action approach significantly reduces the average number of feedback bits while maintaining reliability only when needed.
2Quantity of substance
If two-part HARQ-ACK compression is applied to reduce feedback bits, then uplink resource usage decreases, but system complexity increases due to additional processing requirements
Solution Approach 1:
The UE performs preliminary evaluation of code block statuses before transmission and determines in advance whether to transmit only Part 1 or both Part 1 and Part 2 based on the uniformity of code block acknowledgment statuses. This preliminary action allows the system to make optimal transmission decisions without requiring complex real-time processing at the transmitter, reducing overall system complexity while achieving resource efficiency.
Solution Approach 2:
The two-part HARQ-ACK compression mechanism dynamically adapts the feedback transmission based on the actual code block statuses. When all code blocks have the same status (all ACK or all NACK), the system dynamically switches to transmitting only the compact Part 1. When mixed statuses are detected, it dynamically includes the full Part 2. This dynamic behavior allows the system to optimize resource usage adaptively without requiring complex predetermined configurations.
3Measurement precision
If all HARQ-ACK bits are transmitted to ensure complete feedback, then decoding accuracy is maintained, but transmission overhead and latency increase
Solution Approach 1:
The patent extracts the essential decoding information needed for the gNB to make scheduling decisions into a compact Part 1 that can be transmitted quickly. When all code blocks have the same status, this extracted compact indication is sufficient for the gNB to proceed with retransmission decisions without waiting for the full detailed feedback. This extraction approach maintains decoding accuracy for the most common scenarios while significantly reducing transmission time and latency.
Data Source
AI summary
A method of wireless communication by a user equipment (UE) includes converting a block of hybrid automatic repeat request acknowledgment (HARQ-ACK) bits from an original HARQ-ACK codebook into a partition, a number of partitions for a number of blocks corresponding to quantized HARQ-ACK bits. The method also includes transforming the quantized HARQ-ACK bits into a two part HARQ-ACK payload. The method further includes separately encoding a first part and a second part of the two part HARQ-ACK payload. The method also includes transmitting, to a network node, the encoded first part and the encoded second part.