User Equipment Sub-band Selection for D2D Interference Avoidance
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Solution Overview
Problem
In device-to-device (D2D) communication, mutual interference occurs when different user equipment select the same resource for signal transmission, leading to receiving failures and low communication reliability, as devices cannot receive signals on another frequency band simultaneously.
Innovation Solution
User equipment determines a channel detection cycle, assesses interference strengths within the system bandwidth, and selects sub-bands with relatively low interference for signal transmission, ensuring that the sum of interference on selected sub-bands is less than or equal to any other sub-bands, thereby avoiding transmission collisions and reducing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If user equipment autonomously selects D2D transmission resources without base station coordination, then resource allocation flexibility and communication efficiency are improved, but mutual interference occurs when different devices select the same time-frequency resource
Solution Approach 1:
The patent applies preliminary action by performing channel detection and interference assessment before resource selection. User equipment detects channel occupancy and evaluates interference levels on potential sub-bands prior to transmitting, ensuring that resources are pre-cleared of conflicts. This prevents mutual interference by anticipating and avoiding occupied resources before transmission begins.
Solution Approach 2:
The patent implements feedback mechanisms where user equipment continuously monitors channel conditions, detects interference from other devices, and adjusts resource selection based on this feedback. The system uses detected channel occupancy and interference measurements to dynamically modify transmission decisions, creating a closed-loop control that resolves the contradiction between autonomous allocation and interference avoidance.
2Productivity
If user equipment transmits on multiple sub-bands simultaneously to increase data rate, then communication throughput is improved, but interference with other devices' reception increases
Solution Approach 1:
The patent applies local quality by assessing interference conditions individually for each sub-band and making differentiated transmission decisions. Instead of uniformly transmitting across all available sub-bands, the system evaluates local interference characteristics on each sub-band and selectively transmits only on sub-bands with acceptable interference levels, thereby maintaining high throughput while minimizing harm to other devices.
Solution Approach 2:
The patent changes transmission parameters dynamically based on detected interference conditions. The system adjusts which sub-bands are used for transmission, modifies transmission power levels, and adapts resource allocation based on real-time channel measurements. This parameter adaptation allows the system to optimize data rate while controlling interference to other devices.
3Reliability
If user equipment performs channel detection frequently to avoid interference, then receiving reliability is improved, but channel detection overhead and transmission delay increase
Solution Approach 1:
The patent applies partial action by performing channel detection on a selective basis rather than exhaustively monitoring all possible resources. The system detects channel conditions on representative sub-bands or uses partial channel state information to infer overall channel quality, reducing detection overhead while maintaining sufficient reliability for accurate resource selection.
Solution Approach 2:
The patent uses preliminary channel detection results to cache or predict future channel conditions, reducing the need for frequent repeated detections. By performing initial channel assessments and using this information to guide subsequent transmission decisions, the system reduces channel detection time while maintaining reliable interference avoidance.
Data Source
AI summary
Embodiments provide a method for sending a signal by user equipment and user equipment. The method includes: within an obtained channel detection cycle, detecting a first interference strength within system bandwidth and a second interference strength on each sub-band within the system bandwidth; comparing the first interference strength with a first interference threshold; if the first interference strength is less than the first interference threshold, selecting, from the system bandwidth according to the second interference strength on each sub-band within the system bandwidth, N first sub-bands that receive relatively small interference; and sending a signal on the N first sub-bands. In consideration of interference within the entire bandwidth and interference to each sub-band, when interference to the entire system is relatively small, a transmission collision is avoided. In addition, selecting sub-bands that receive small interference for signal transmission further reduces transmission interference, thereby effectively improving data transmission reliability.