Uplink HARQ Repetition Control for Reliable Low-Latency PUSCH
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems face challenges in achieving ultra-reliable and low-latency communications, particularly in designing effective hybrid automatic repeat request (HARQ) mechanisms that meet the stringent latency and reliability requirements for uplink transmissions in 5G networks.
Innovation Solution
The implementation of a hybrid automatic repeat request (HARQ) mechanism that supports various transmission types, including scheduling request-triggered, fast, grant-based, and grant-free initial and retransmission schemes, with dynamic configuration of repetition numbers and periodicity, using different Radio Network Temporary Identifiers (RNTIs) and search spaces to optimize resource allocation and scheduling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional HARQ mechanisms are used in wireless communication systems, then the system structure remains simple and easy to implement, but the latency and reliability requirements for uplink transmissions cannot be met
Solution Approach 1:
The patent segments the HARQ mechanism into multiple transmission types (scheduling request-triggered, fast, grant-based, and grant-free) with different levels of complexity. Each transmission type is further divided into initial transmission and retransmission phases, allowing the system to select appropriate segments based on latency and reliability requirements without requiring complete redesign of the entire HARQ mechanism.
Solution Approach 2:
The patent introduces dynamic configuration parameters including repetition numbers, periodicity, and search space configurations that can be adjusted based on channel conditions and service requirements. The system dynamically selects between different transmission types and configures HARQ process parameters adaptively, transforming the static traditional HARQ mechanism into a dynamic system that can meet varying URLLC requirements.
2Loss of time
If multiple transmission types and dynamic configurations are implemented to meet URLLC requirements, then latency and reliability are improved, but the system complexity and resource allocation difficulty increase
Solution Approach 1:
The patent implements preliminary configuration of HARQ parameters including repetition numbers, periodicity, and search space assignments before actual transmissions occur. The system pre-configures multiple transmission types and their associated parameters, allowing rapid selection and execution during URLLC transmissions without requiring complex real-time decision-making, thus reducing latency while managing system complexity.
Solution Approach 2:
The patent introduces search spaces as intermediary structures that organize and manage different transmission types and their associated control information. By using search spaces as intermediaries between the physical layer transmissions and higher-layer configurations, the system simplifies resource allocation and reduces the complexity of managing multiple transmission types with different parameters.
3Speed
If grant-free transmission schemes are used to reduce latency, then transmission speed is improved, but resource allocation efficiency and scheduling control are degraded
Solution Approach 1:
The patent applies different resource allocation strategies to different transmission types and scenarios. Grant-free transmission is configured with specific repetition numbers and periodicity parameters optimized for low-latency applications, while grant-based transmissions use more sophisticated scheduling. This local optimization allows grant-free schemes to achieve high transmission speed where needed without compromising overall resource allocation efficiency across the system.
Solution Approach 2:
The patent implements feedback mechanisms where the system monitors the performance of grant-free transmissions and adjusts configuration parameters such as repetition numbers, periodicity, and search space assignments based on observed latency and reliability metrics. This feedback loop enables the system to maintain high transmission speed while improving resource allocation efficiency over time through adaptive configuration.
Data Source
AI summary
A user equipment (UE) is described. The UE includes receiving circuitry configured to receive a radio resource control message including first information used for configuring a number of repetitions and a periodicity, the number of the repetitions being for transmissions of a transport block (TB). The receiving circuitry receives a radio resource control message including second information used for configuring a monitoring occasion for a symbol. The receiving circuitry monitors a first physical downlink control channel (PDCCH) with cyclic redundancy check (CRC) scrambled by a cell radio network temporary identifier (C-RNTI). The receiving circuitry monitors a second PDCCH with CRC scrambled by a second RNTI different from the C-RNTI. The UE also includes transmitting circuitry configured to perform on a physical uplink shared channel (PUSCH), based on the first information, transmissions of the TB.