PDSCH Frequency Hopping Across Available RB Sets
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Solution Overview
Problem
In new radio (NR) communication, the overhead of blind DCI detection becomes heavy when small time slot durations are used due to separate scheduling of each PDSCH, which is exacerbated by frequency hopping in unavailable RB sets, affecting normal PDSCH reception by user equipment (UE).
Innovation Solution
Implementing a method for transmitting PDSCHs using a frequency hopping rule across multiple available DL resource block (RB) sets within a bandwidth part (BWP), ensuring PDSCHs are scheduled by DCI only on available RB sets, thereby avoiding mapping to unavailable RB sets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If each PDSCH is scheduled by a separate DCI to ensure scheduling flexibility, then scheduling flexibility is improved, but the overhead of blind DCI detection increases heavily
Solution Approach 1:
The patent merges multiple PDSCH scheduling operations into a single DCI message by introducing a multi-TTI scheduling mechanism. The DCI format is extended to include multiple resource allocation fields, allowing one DCI to schedule multiple PDSCH transmissions across different time slots, thereby reducing the number of DCI messages and blind detection overhead while maintaining scheduling flexibility.
Solution Approach 2:
The patent implements dynamic multi-TTI scheduling where the number of time slots scheduled by a single DCI can be dynamically adjusted based on channel conditions, traffic requirements, and UE capabilities. The DCI includes dynamic indicators that allow the base station to flexibly configure the scheduling horizon, enabling adaptation to varying system conditions while reducing control overhead.
2Productivity
If the time slot duration is reduced to increase scheduling granularity, then scheduling granularity is improved, but the number of DCIs to be detected increases
Solution Approach 1:
The patent combines multiple fine-grained time slot allocations into a single DCI message by implementing multi-slot scheduling. Instead of sending separate DCIs for each short time slot, the system uses one DCI to allocate resources across multiple consecutive slots, maintaining fine scheduling granularity while reducing the total number of DCI messages that need to be detected.
Solution Approach 2:
The patent performs preliminary resource allocation for multiple time slots in advance through a single DCI message. The base station pre-configures resource allocations for future slots within the scheduled horizon, allowing the UE to prepare reception resources beforehand without needing to detect separate DCIs for each slot, thus reducing detection complexity while maintaining granularity.
3Reliability
If frequency hopping is applied to PDSCH for diversity gain, then transmission reliability is improved, but PDSCH may be mapped to unavailable RB sets causing reception failure
Solution Approach 1:
The patent applies preliminary action by having the base station indicate available RB sets to the UE in advance through higher layer signaling (RRC configuration) before PDSCH transmission. The frequency hopping pattern and target RB sets are pre-configured and validated to ensure they fall within available resources, preventing mapping errors while maintaining diversity gain from frequency hopping.
Solution Approach 2:
The patent implements feedback mechanisms where the base station receives information about available RB sets from the network side (considering interference, congestion, or reserved resources) and uses this feedback to configure appropriate frequency hopping patterns. The DCI includes indicators that guide the UE to hop only to currently available RB sets, ensuring reliable reception while maintaining frequency diversity.
Data Source
AI summary
A method for transmitting physical downlink shared channel (PDSCH) includes: sending, by a network device based on a frequency hopping rule and multiple available downlink (DL) resource block (RB) sets in a DL bandwidth pad (BWP), multiple PDSCHs scheduled by downlink control information (DCI) in a first format to a user equipment (UE).