Multi-Carrier PUSCH/PDSCH Scheduling for URLLC in NR-U
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Solution Overview
Problem
In 5G New Radio (NR) unlicensed spectrum, the challenges of Ultra-Reliable Low Latency Communications (URLLC) include failed Listen Before Talk (LBT) leading to latency issues, hidden node interference affecting reliability, and high control signaling overhead due to separate LBT on each subband/carrier for multiple PUSCH/PDSCH scheduling.
Innovation Solution
Implementing a method for scheduling PUSCH/PDSCH on unlicensed spectrum using a single DCI format to allocate resources efficiently across multiple subbands/carriers, ensuring equal subband distribution and independent LBT per subband, with options for TB repetition and HARQ processes to enhance reliability and reduce signaling overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple uplink and downlink component carriers are configured for a user equipment, then the data transmission capacity and system throughput are improved, but the complexity of scheduling and resource allocation increases
Solution Approach 1:
The patent segments the scheduling process into two independent parts: uplink grant scheduling and downlink data scheduling. The network device can independently determine uplink grants for PUSCH transmissions and downlink data assignments for PDSCH transmissions without requiring complex joint optimization, thereby reducing overall scheduling complexity while maintaining high throughput in multi-carrier configurations
Solution Approach 2:
The patent applies preliminary action by allowing the network device to pre-determine and send uplink grants for PUSCH transmissions before the actual uplink data transmission occurs. This enables the user equipment to prepare and transmit uplink data on scheduled resources without waiting for dynamic scheduling decisions, reducing scheduling latency and complexity in multi-carrier scenarios
2Productivity
If PUSCH and PDSCH are scheduled in the same slot, then the resource utilization efficiency is improved, but the probability of interference and scheduling conflicts increases
Solution Approach 1:
The patent introduces a timing relationship parameter (such as K2 offset) as an intermediary between uplink grant reception and PUSCH transmission. This parameter acts as a buffer that separates the scheduling decision from the actual transmission timing, allowing the network to coordinate uplink and downlink resources in the same slot while avoiding direct conflicts through controlled timing offsets
Solution Approach 2:
The patent implements dynamic scheduling where the network device can flexibly adjust the timing relationship between uplink grants and PUSCH transmissions based on current downlink resource availability. This dynamic adjustment allows PUSCH and PDSCH to share the same slot when resources permit, while automatically preventing conflicts when downlink resources are occupied, thus maintaining high resource utilization with reliable conflict avoidance
3Stability of the object's composition
If the network device determines PUSCH transmission timing based on downlink slot timing, then the synchronization between uplink and downlink is improved, but the flexibility in uplink resource allocation is reduced
Solution Approach 1:
The patent uses preliminary action by providing downlink slot timing information in advance through downlink control information (DCI). The network device indicates the downlink slot timing to the user equipment, which then uses this information to determine the corresponding uplink PUSCH transmission timing. This preliminary provision of timing information maintains synchronization while allowing flexible uplink resource allocation based on the indicated timing relationships
Solution Approach 2:
The patent changes the timing relationship parameter (such as K2 offset) dynamically to balance synchronization and flexibility. By adjusting this parameter, the network can maintain stable timing relationships for synchronization purposes while adapting uplink resource allocation to varying downlink resource conditions, thus resolving the contradiction between synchronization stability and allocation flexibility
Data Source
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Figure 3(a)
AI summary
The present disclosure relates to a method and apparatus for scheduling PUSCH or PDSCH. One embodiment of the subject disclosure provides a method for scheduling Physical Uplink Shared Channel (PUSCH), comprising: receiving a signal scheduling a first number of PUSCHs on a second number of frequency resources, wherein the first number of PUSCHs are scheduled with same time domain resource; and transmitting one or more PUSCHs of the first number of PUSCHs on the second number of frequency resources.