NB-IoT HARQ Feedback Aggregation for Power Saving
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Solution Overview
Problem
The current Narrow Band Internet of Things (NB-IoT) system experiences excessive power consumption due to the need for multiple Narrowband Physical Uplink Shared Channel (NPUSCH) feedbacks for Hybrid Automatic Repeat Request (HARQ) results, which prolongs feedback duration and is not conducive to power saving.
Innovation Solution
A method and apparatus for NB-IoT devices to determine a combined HARQ result from multiple target HARQ results corresponding to Physical Downlink Shared Channels (PDSCHs) scheduled by a Physical Downlink Control Channel (PDCCH), representing these results with a single NPUSCH, reducing resource consumption and improving efficiency by using logical operations and optimized resource allocation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If one NPUSCH is required for feedback for each PDSCH, then HARQ feedback can be provided for each downlink channel, but excessive NPUSCHs are consumed which prolongs feedback duration and increases power consumption
Solution Approach 1:
The patent combines multiple individual HARQ feedback signals into a single combined feedback signal. Instead of transmitting separate NPUSCH signals for each PDSCH, the system merges these feedbacks into one unified signal that carries information about multiple downlink channels, thereby reducing the number of NPUSCH transmissions and associated power consumption while maintaining feedback completeness
Solution Approach 2:
The combined feedback signal serves multiple functions simultaneously. A single NPUSCH transmission carries HARQ feedback information for multiple PDSCHs, making the feedback mechanism universal rather than dedicated to individual channels. This multi-functional approach reduces the total number of feedback transmissions required
2Loss of information
If multiple NPUSCHs are used for feedback, then each HARQ result can be transmitted individually, but feedback duration is prolonged which is not conducive to power saving
Solution Approach 1:
Multiple feedback transmissions are merged into a single combined feedback signal. The system aggregates HARQ result information from multiple PDSCHs and transmits it in one NPUSCH, thereby reducing the total feedback duration and the time the device remains active, which directly addresses the power saving concern while preserving complete information transmission
3Productivity
If one PDCCH schedules multiple PDSCHs, then scheduling efficiency is improved, but the device needs to demodulate multiple PDCCHs which is power-consuming
Solution Approach 1:
The system performs preliminary actions by having the base station indicate in advance which PDSCHs are scheduled by a single PDCCH. This allows the terminal to prepare for efficient processing by knowing ahead of time which feedback signals need to be combined, reducing the computational burden and power consumption during the feedback generation process
Data Source
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AI summary
A hybrid automatic repeat request (HARQ) feedback method and apparatus are provided. The method includes: determining a plurality of target HARQ results, in which the plurality of target HARQ results are HARQ results corresponding to a plurality of target physical downlink shared channels (PDSCH), and the plurality of target PDSCHs are PDSCHs scheduled by a current physical downlink control channel (PDCCH); determining a combined HARQ result based on the plurality of target HARQ results, wherein the combined HARQ result is used for representing the plurality of target HARQ results; determining a target narrowband physical uplink shared channel (NPUSCH), wherein the target NPUSCH is a NPUSCH with a target resource carrying the combined HARQ result; and carrying the combined HARQ result by the target resource and sending the target NPUSCH to a base station.