MIRS Packet Coding for Dynamic Unlicensed-Band Link Adaptation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Link quality prediction is difficult in unlicensed bands, making CSI-RS based link adaptation inefficient, and existing methods like CSI-RS based channel capacity tracking fail to adapt to instantaneous optimal modulation and coding schemes, leading to suboptimal throughput.
Innovation Solution
Implementing a Multiple Incremental Redundancy Scheme (MIRS) where packets are transmitted with a single first packet size, allowing for dynamic adaptation based on ACK/NACK feedback to achieve optimal coding rates, even in unpredictable interference environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If CSI-RS based link adaptation is used, then channel capacity tracking is enabled, but it fails to adapt to instantaneous optimal modulation and coding schemes in unlicensed bands
Solution Approach 1:
The patent implements dynamic link adaptation by continuously adjusting modulation and coding schemes based on instantaneous channel conditions in unlicensed bands, rather than relying on periodic CSI-RS measurements. The system dynamically selects from multiple coding rates and modulation orders to match real-time channel quality, enabling adaptation to instantaneous optimal parameters.
Solution Approach 2:
The patent employs feedback mechanisms where the UE reports channel quality indicators and decoding success/failure information back to the network node. This feedback loop enables the network to adjust transmission parameters adaptively, improving link reliability by correcting suboptimal parameter selections based on actual channel performance.
2Productivity
If fixed packet size transmission is used, then transmission simplicity is maintained, but throughput is limited due to inability to adapt to channel conditions
Solution Approach 1:
The patent changes transmission parameters including packet size, coding rate, and modulation order based on channel conditions. The network node selects from multiple predefined packet sizes and dynamically adjusts the coding rate within each packet, allowing throughput optimization without requiring completely flexible packet structures.
Solution Approach 2:
The transmission scheme becomes dynamic by adapting packet size and coding rate selections based on real-time channel quality assessments. The system transitions from fixed parameter transmission to dynamic parameter selection, improving throughput while maintaining manageable complexity through a finite set of predefined options.
3Reliability
If conventional HARQ with variable packet sizes is used, then some adaptation is possible, but performance degrades in unpredictable interference environments
Solution Approach 1:
The patent applies different coding rates to different portions or aspects of the transmission based on local channel conditions. By selecting appropriate coding rates from multiple options for specific transmissions, the system optimizes reliability for each transmission instance while maintaining robustness against interference through conservative coding rate selection when conditions are poor.
Solution Approach 2:
The system prepares multiple coding rate options and redundancy versions in advance, cushioning against unpredictable interference by having pre-computed fallback options ready. When interference is detected or predicted, the system can switch to more robust pre-prepared coding schemes, reducing the impact of interference before it degrades performance.
Data Source
AI summary
A network node may identify a single first packet size associated with a plurality of packets. The network node may transmit the plurality of packets to a UE based on a MIRS. Each packet in the plurality of packets may be associated with the single first packet size. The UE may decode the plurality of packets based on the MIRS. Each packet in the plurality of packets may include a first number of systematic bits and a second number of parity bits. The first number of systematic bits may be associated with a first cyclic buffer at the network node. The second number of parity bits may be associated with a second cyclic buffer at the network node.