Semi-autonomous Uplink Scheduling in Shared Spectrum
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Solution Overview
Problem
Current wireless communication systems face challenges in efficiently scheduling uplink transmissions in shared radio frequency spectrum bands, leading to reduced uplink throughput due to factors like fixed transmission timing and interference from hidden nodes.
Innovation Solution
The implementation of semi-autonomous scheduling techniques for uplink transmissions in shared radio frequency spectrum bands, where user equipment (UE) can contend for access based on a Listen Before Talk (LBT) procedure and adjust transmission timing within a specified transmission window.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If fixed transmission timing is used for uplink transmissions in shared spectrum bands, then network coordination is simplified, but uplink throughput is reduced due to inability to adapt to channel availability
Solution Approach 1:
The patent implements dynamic transmission timing where UEs can adjust their transmission start times within a configured window based on LBT outcomes. The network configures a transmission window with multiple candidate start times, and UEs dynamically select appropriate timing based on channel access success, transforming fixed scheduling into adaptive scheduling that responds to real-time channel conditions.
Solution Approach 2:
The patent enables UEs to autonomously determine transmission timing by performing LBT procedures and selecting transmission start times within the configured window without requiring real-time network coordination. The UE independently monitors channel availability, contends for access, and autonomously schedules its transmission, reducing signaling overhead and network complexity.
2Object-affected harmful factors
If Listen Before Talk procedure is implemented for channel access, then interference from hidden nodes is reduced, but transmission latency increases due to contention delays
Solution Approach 1:
The patent performs LBT procedures in advance within the transmission window before actual data transmission. By configuring a window of candidate start times and performing channel sensing beforehand, the system prepares for transmission proactively, allowing UEs to identify available time slots ahead of time and reduce actual transmission delays.
Solution Approach 2:
The patent implements dynamic selection of transmission start times based on real-time LBT outcomes. Instead of using fixed timing or single-attempt contention, UEs can adaptively choose from multiple candidate start times within the window, dynamically adjusting transmission timing to balance channel access success probability with latency requirements.
3Ease of operation
If UEs autonomously contend for channel access, then network coordination overhead is reduced, but transmission timing synchronization deteriorates
Solution Approach 1:
The patent applies different timing characteristics to different portions of the transmission window. Early candidate start times are suitable for UEs that gain channel access quickly, while later candidates accommodate UEs requiring more sensing time or experiencing longer contention delays. This local differentiation maintains relative timing relationships among multiple UEs while allowing autonomous access.
Solution Approach 2:
The patent enables dynamic timing adjustment where UEs autonomously select transmission start times based on their individual LBT outcomes within the configured window. This dynamic approach allows each UE to adapt its timing independently while the overall system maintains synchronization through the pre-configured window structure, balancing autonomy with coordination.
Data Source
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AI summary
Techniques are described for wireless communication. One method includes receiving, from a network access device, an uplink grant to transmit over a channel of a shared radio frequency spectrum band. The uplink grant indicates a number of subframes and a transmission window having a duration of a plurality of subframes. The method further includes contending for access to the channel of the shared radio frequency spectrum band based at least in part on a listen before talk (LBT) procedure and in accordance with the uplink grant; and transmitting an uplink transmission over the channel of the shared radio frequency spectrum band, in accordance with the uplink grant. A starting subframe of the uplink transmission is based at least in part on the LBT procedure and is within the transmission window.