Grant-Free Scheduling for Low-Latency Wireless Access
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Solution Overview
Problem
Conventional mobile communication systems face challenges in predicting channel performance due to fluctuations, leading to inaccurate scheduling, reduced spectral efficiency, and energy inefficiency, especially in environments where uplink reference signals are transmitted before scheduling, causing delays and discarding unused channel information.
Innovation Solution
A scheduling method for grant-free multiple access that receives traffic, network, and status information from user terminals, forms scheduling groups based on long-term channel and energy information, and allocates resources to minimize interference and ensure low-latency, high-reliability services by computing SINR and determining optimal pilot lengths and transmission powers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If uplink reference signals are transmitted before scheduling, then channel information can be obtained for scheduling decisions, but the number of reference signals increases proportionally with the number of user terminals, reducing spectral efficiency
Solution Approach 1:
The patent extracts only the necessary channel information from the reference signals for scheduling decisions, rather than requiring all user terminals to transmit full reference signals before scheduling. This selective extraction approach maintains channel information accuracy while reducing the overall number of reference signals needed in the system.
Solution Approach 2:
The patent performs preliminary scheduling decisions based on available channel information without requiring complete reference signal transmission from all users first. By making scheduling decisions with partial information and refining them subsequently, the system reduces the number of reference signals required while maintaining scheduling accuracy.
2Measurement precision
If uplink reference signals are transmitted before scheduling, then channel estimation can be performed, but the energy efficiency of user terminals deteriorates due to unnecessary transmissions
Solution Approach 1:
The patent implements partial action by requiring only certain user terminals to transmit reference signals based on their channel conditions and scheduling priorities, rather than all terminals transmitting before scheduling. This partial transmission approach maintains adequate channel estimation accuracy for scheduled users while reducing energy consumption for terminals that do not require scheduling.
Solution Approach 2:
User terminals autonomously determine whether to transmit reference signals based on their own channel conditions and scheduling needs, rather than all terminals blindly transmitting. This self-service approach allows terminals to avoid unnecessary energy-consuming transmissions when their channel information is already sufficient or when they are not priority users.
3Productivity
If resource allocation occurs at the subframe level, then scheduling decisions can be made, but considerable delays are unavoidable
Solution Approach 1:
The patent segments the scheduling process into multiple stages occurring within a single subframe, rather than completing all scheduling decisions at the subframe boundary. By dividing scheduling into earlier stages (channel estimation, preliminary scheduling) and later stages (resource allocation), the system reduces scheduling delay while maintaining comprehensive scheduling capability.
Solution Approach 2:
The patent performs preliminary scheduling decisions and resource preparations before the subframe allocation point, rather than making all decisions at the subframe level. This preliminary action includes identifying which users need scheduling, estimating their channel conditions, and preparing resource assignments in advance, thereby reducing the actual scheduling delay while maintaining full scheduling capability.
Data Source
AI summary
A scheduling method for grant-free multiple access, and a user terminal for the same are disclosed. The method comprises: (a) a step of receiving, from the user terminal, information on traffic to be served, network information of the user terminal and state information of the user terminal; (b) a scheduling step of forming scheduling groups on the basis of the information received in step (a) and a step of allocating resources to each scheduling group; and (c) providing scheduling information to the user terminal, wherein traffic aggregations for traffic of the terminal are set on the basis of the information on traffic from the terminal, the scheduling groups are formed according to the traffic aggregations, and the scheduling information is provided to each traffic aggregation by which the user terminal is to be served.