Grant-Free Wireless Transmission for Small Traffic
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing scheduling-based transmission schemes in LTE networks are inefficient for small packet transmissions, leading to increased dynamic signal overhead and inability to meet Quality of Experience (QoE) requirements for delay-sensitive applications like real-time gaming and machine-to-machine communications.
Innovation Solution
Implementing a grant-free transmission mode in both downlink and uplink channels, where mobile devices receive and transmit packets without traditional grant-based signaling, using blind detection and pre-defined transmission codes to reduce overhead and enhance spectrum efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If dynamic scheduling based transmission is used, then system capacity is boosted through fast link adaptation, but signaling overhead increases
Solution Approach 1:
The patent applies preliminary action by pre-configuring search spaces and access spaces for multiple mobile devices before actual data transmission occurs. The base station pre-allocates time-frequency resources and transmission codes to devices, so that when data needs to be transmitted, the devices can immediately access pre-defined resources without requiring real-time grant-based signaling. This eliminates the need for dynamic grant allocation while maintaining link adaptation capabilities through pre-configured parameters.
2Manufacturing precision
If grant-based signaling is used for each transmission, then resource allocation is precise, but transmission delay increases
Solution Approach 1:
The patent implements preliminary action by pre-establishing search spaces and access spaces with specific time-frequency resources and transmission codes before actual transmission. Mobile devices are pre-configured with these resources, allowing them to transmit data immediately when ready without waiting for real-time grant signaling. This maintains precise resource allocation through pre-defined configurations while eliminating transmission delay caused by grant-based signaling protocols.
3Loss of information
If semi-persistent scheduling is used, then signaling overhead is reduced, but adaptability to changing link conditions deteriorates
Solution Approach 1:
The patent applies dynamics by enabling mobile devices to dynamically select from pre-configured search spaces and access spaces based on current link conditions. Devices can switch between different pre-established resource allocations and transmission codes according to channel quality, maintaining adaptability without requiring continuous dynamic signaling. The system combines the low overhead of semi-persistent scheduling with the adaptability of dynamic scheduling through this hybrid approach.
4Device complexity
If traditional scheduling-based access is used, then resource allocation is controlled, but spectrum efficiency for small packets deteriorates
Solution Approach 1:
The patent implements preliminary action by pre-allocating multiple search spaces and access spaces with different time-frequency resources and transmission codes before actual packet transmission. When small packets need to be transmitted, devices can immediately access pre-configured resources without undergoing complex scheduling procedures. This maintains controlled resource allocation through pre-established configurations while dramatically improving spectrum efficiency for small packets by eliminating scheduling overhead.
Data Source
AI summary
A grant-free transmission mode may be used to communicate small traffic transmissions to reduce overhead and latency. The grant-free transmission mode may be used in downlink and uplink data channels of a wireless network. In the downlink channel, a base station transmits packets to a group of UEs in a search space without communicating any transmission code assignments to the UEs. The UEs receive the downlink packets using blind detection. In the uplink channel, UEs transmit packets in an access space using assigned access codes which are either independently derived by the UEs or otherwise communicated by the base station using a slow-signaling channel. Hence, the grant-free transmission mode allows mobile devices to make small traffic transmissions without waiting for uplink grant requests.