PDSCH Feedback Scheduling with DCI-Guided Timing
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Solution Overview
Problem
Existing communication systems face challenges in efficiently managing discontinuous reception and hybrid automatic repeat request (HARQ) feedback in multicarrier communication systems, particularly in scenarios involving multiple carriers and varying numerologies.
Innovation Solution
Implementing mechanisms for discontinuous reception (DRX) and HARQ feedback transmission in multicarrier systems, including logical channel prioritization and dynamic resource allocation based on channel state information (CSI) to optimize resource usage and reduce power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If discontinuous reception (DRX) is implemented to reduce power consumption, then energy efficiency improves, but system complexity increases due to coordination requirements across multiple carriers with varying numerologies
Solution Approach 1:
The patent segments the DRX operation into carrier-specific configurations, allowing each carrier to have independent DRX parameters (drx-OnDurationTimer, drx-SleepTimer, etc.) while maintaining coordinated operation. This segmentation enables the system to manage power consumption per carrier without requiring complex global coordination, thus reducing overall system complexity while achieving energy efficiency.
Solution Approach 2:
The patent introduces a new dimension of carrier aggregation to the DRX framework, where multiple carriers with different numerologies operate under a unified DRX structure. By adding the carrier dimension, the system can independently optimize power saving for each carrier while maintaining overall coordination through the parent carrier's DRX configuration, resolving the complexity issue.
2Reliability
If HARQ feedback is transmitted frequently to improve reliability, then communication reliability improves, but uplink resource consumption increases
Solution Approach 1:
The patent implements periodic HARQ feedback transmission aligned with the DRX cycle structure. HARQ acknowledgments are transmitted at specific periodic intervals (e.g., at the end of each DRX active period) rather than continuously, which maintains communication reliability for critical feedback while significantly reducing overall uplink resource consumption by eliminating redundant feedback transmissions during sleep periods.
Solution Approach 2:
The patent makes HARQ feedback timing dynamic by linking it to DRX state transitions. When the UE transitions from sleep to active state, HARQ feedback is prioritized and transmitted immediately if data is available. This dynamic timing adapts to traffic conditions, ensuring reliability when needed while conserving resources during low-activity periods.
3Productivity
If resource allocation is optimized based on channel state information (CSI) to improve spectral efficiency, then data transmission efficiency improves, but measurement and processing requirements increase
Solution Approach 1:
The patent applies local quality optimization by configuring CSI measurement and reporting differently for each carrier based on its specific characteristics (numerology, traffic type, channel conditions). Primary carriers with critical services receive frequent and detailed CSI monitoring, while secondary carriers with best-effort traffic use reduced CSI reporting. This localized approach maximizes data transmission efficiency for important traffic while reducing overall measurement and processing requirements.
Solution Approach 2:
The patent dynamically changes CSI reporting parameters (reporting periodicity, measurement bandwidth, reporting granularity) based on DRX state and carrier priority. During active DRX periods, CSI reporting frequency increases to enable rapid resource allocation adjustments. During sleep periods, CSI reporting is reduced or suspended. This parameter adaptation maintains high data transmission efficiency during active periods while significantly reducing processing requirements during low-activity periods.
Data Source
AI summary
A wireless device may receive from a base station a first downlink control information (DCI) scheduling a physical downlink shared channel (PDSCH) transmission. The first DCI may indicate that the wireless device is not to transmit feedback for the PDSCH transmission before receiving a second DCI and a PDSCH group index. The second DCI may indicate a time slot for transmitting feedback and the PDSCH group index. In response to the wireless device receiving the second DCI and based on the second DCI indicating feedback for the same PDSCH group index as the first DCI, the wireless may transmit to the base station, in the time slot indicated, the feedback for the PDSCH transmission.