Implicit Acknowledgement Signaling in HARQ Resource Allocation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current radio communication systems, such as 3GPP LTE, face inefficiencies in bandwidth usage due to explicit acknowledgement and negative acknowledgement signaling in the HARQ scheme, which consumes valuable network resources and is vulnerable to errors.
Innovation Solution
The implementation of implicit acknowledgement signaling through resource allocation messages, where a New Data Indicator (NDI) field in allocation messages indicates whether a transmission is for a new packet or retransmission, eliminating the need for explicit ACK/NAK messages and reducing downlink signaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If explicit ACK/NAK signaling is used in HARQ scheme, then reliable error control is achieved, but bandwidth resources are consumed and signaling overhead increases
Solution Approach 1:
The patent combines the acknowledgement signaling function with the existing uplink resource allocation messages ( grants). Instead of using separate dedicated ACK/NAK channels, the NDI field in the uplink grant messages is repurposed to carry acknowledgement information. This merging eliminates the need for separate inband ACK/NAK resources while maintaining reliable error control through the same signaling mechanism.
2Reliability
If explicit ACK/NAK signaling is implemented, then error detection and retransmission control are improved, but device complexity and processing overhead increase
Solution Approach 1:
The uplink resource allocation message is given multi-functionality: it simultaneously performs resource scheduling and error acknowledgement functions. The NDI field, traditionally used only for new data indication, now also conveys ACK/NAK information based on its value changes. This universality reduces the need for separate signaling structures and processing logic for dedicated ACK/NAK channels.
3Reliability
If separate inband resources are reserved for explicit acknowledgement signaling, then reliable feedback is ensured, but network resource efficiency decreases
Solution Approach 1:
The existing uplink resource allocation mechanism serves dual purposes: it allocates resources for uplink transmission and simultaneously provides feedback (ACK/NAK) for downlink data reception. The base station uses the same signaling infrastructure to both schedule uplink resources and acknowledge downlink packet reception status, eliminating the need for separate feedback resources and improving overall network resource efficiency.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A resource allocation message comprising a first indication that resource allocation is intended for a first transmission of data or a second, different indication that the resource allocation is intended for retransmission of the data is received, the data being retransmitted in response to a received resource allocation message comprising the second indication. An explicit acknowledgment/negative acknowledgment signaling sent regarding the data is ignored.