Unlicensed Spectrum Transmission Mode Selection for Interference Reduction
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Solution Overview
Problem
In wireless communication systems using unlicensed spectra, terminal devices at far locations experience severe signal attenuation, leading to mutual signal interference and reduced network performance due to differences in detection capabilities, and existing scheduling-based transmission modes are not suitable for all devices, increasing scheduling signaling overheads.
Innovation Solution
A method where terminal devices select a transmission mode based on user attributes and data packet attributes within a channel occupancy time window, using a mixed transmission method that combines contention and scheduling to reduce interference while meeting regulatory constraints, by choosing between contention-based or scheduling-based transmission modes depending on user type and data packet size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a terminal device at a far location performs LBT process in unlicensed spectrum, then the device can detect spectrum occupancy, but severe signal attenuation prevents detection of communication between network device and far terminal device, causing another terminal device to occupy the spectrum and create mutual signal interference
Solution Approach 1:
The patent introduces a network device as an intermediary that performs LBT detection and manages spectrum occupancy on behalf of terminal devices. The network device acts as a mediator that can detect signals from far terminal devices that individual terminal devices cannot detect due to signal attenuation, thereby preventing mutual interference while maintaining spectrum utilization.
Solution Approach 2:
The patent enables terminal devices to autonomously select transmission modes (contention-based or scheduling-based) based on their coverage characteristics and data packet attributes. This self-service mechanism allows far terminal devices to adaptively choose transmission methods that work within their detection capabilities, reducing interference without requiring constant network intervention.
2Object-affected harmful factors
If scheduling-based transmission mode is used to reduce mutual signal interference, then interference between systems is reduced, but scheduling signaling overheads are increased and downlink channel resources are consumed
Solution Approach 1:
The patent implements a dynamic transmission mode selection mechanism where terminal devices can switch between contention-based and scheduling-based modes based on real-time conditions such as coverage level, data packet size, and network state. This dynamic approach allows the system to use scheduling-based mode only when necessary to reduce interference, thereby minimizing signaling overhead while maintaining interference management benefits.
Solution Approach 2:
The patent changes the parameter of transmission mode from a fixed scheduling-based approach to a variable approach that adapts to different terminal device attributes and data characteristics. By adjusting the transmission mode parameter based on coverage level and data packet attributes, the system achieves interference reduction with optimized signaling overhead.
3Object-affected harmful factors
If scheduling-based transmission mode is used for far terminal devices, then interference is reduced, but multiple scheduling instructions are needed due to severe signal attenuation, increasing scheduling signaling overheads
Solution Approach 1:
The patent applies preliminary action by having terminal devices determine their coverage level and select appropriate transmission modes before actual data transmission. Far terminal devices pre-select contention-based or simplified scheduling modes that require fewer scheduling instructions, thereby reducing the time lost to repeated scheduling signaling while still managing interference effectively.
4Productivity
If contention-based transmission is used in unlicensed spectrum, then spectrum utilization is improved, but mutual signal interference between different systems increases
Solution Approach 1:
The patent applies local quality by differentiating transmission approaches based on terminal device location and coverage characteristics. Near terminal devices use contention-based modes for high spectrum utilization, while far terminal devices use scheduling-based modes for interference control. This localized differentiation optimizes both spectrum utilization and interference management in different spatial regions.
Solution Approach 2:
The patent segments the terminal device population into different coverage groups (near and far terminal devices) and assigns different transmission modes to each segment. This segmentation allows the system to simultaneously achieve high spectrum utilization in near-device regions while controlling interference in far-device regions, optimizing overall system performance.
Data Source
AI summary
The present disclosure provides a method, system, and terminal device for data transmission in an unlicensed spectrum, effectively reduce mutual signal interference between different systems while meeting regulation constraints on use of the unlicensed spectrum. The method in the present disclosure includes: at a processing start moment of a terminal device in a current channel occupancy time window of a network device, when remaining duration of the current channel occupancy time window of the network device is greater than or equal to duration for the terminal device to transmit a to-be-sent data packet to the network device, selecting based on a user attribute of the terminal device and from a mapping relationship between a user attribute and a transmission mode; and sending the to-be-sent data packet to the network device in the selected transmission mode.