Wireless Terminal Coexistence Interference Mitigation
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Solution Overview
Problem
Wireless communication terminals face interference issues due to the simultaneous operation of multiple wireless interfaces, particularly when cellular technologies like LTE coexist with short-range technologies like WiFi or Bluetooth, as the operating frequencies can cause interference, and RF filters do not provide sufficient rejection of adjacent frequencies.
Innovation Solution
The implementation of methods and mechanisms in wireless terminals to mitigate interference by performing measurements, reporting interference levels, triggering coexistence interference avoidance mechanisms, and adapting scheduling and handover strategies based on channel state information and interference thresholds, including inter-frequency handovers, time division multiplexing, and rescheduling of transmissions to minimize interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple wireless interfaces operate simultaneously, then wireless functionality and versatility are improved, but interference between interfaces occurs due to adjacent frequency operations
Solution Approach 1:
The system performs measurements and reports interference levels before interference occurs. The network entity receives measurement reports indicating potential interference conditions and proactively triggers coexistence interference avoidance mechanisms, such as scheduling transmissions during non-overlapping time periods or frequency bands, preventing interference before it degrades performance
Solution Approach 2:
The system dynamically adapts transmission parameters based on real-time interference conditions. The network entity adjusts scheduling decisions, frequency selections, and power levels according to measured interference levels and coexistence conditions, allowing the system to optimize performance under varying operational scenarios while maintaining multiple wireless functionalities
2Measurement precision
If RF filters are used to reject adjacent frequencies, then frequency selectivity is improved, but sufficient rejection of adjacent frequencies cannot be achieved
Solution Approach 1:
The system introduces a measurement and reporting intermediary layer between the wireless interfaces and the network entity. Measurement reports act as intermediaries that convey interference conditions to the network entity, which then triggers appropriate avoidance mechanisms. This intermediary approach enables coordinated interference management that exceeds what passive RF filtering can achieve
Solution Approach 2:
The system implements feedback loops where measurement reports continuously inform network entity decisions about transmission scheduling and resource allocation. The network entity uses this feedback to adjust transmissions dynamically, creating a closed-loop system that actively manages interference rather than relying solely on passive filtering
3Object-affected harmful factors
If coexistence interference avoidance mechanisms are triggered, then interference between interfaces is reduced, but operating efficiency may be impacted
Solution Approach 1:
The system applies interference avoidance mechanisms selectively rather than continuously. Coexistence interference avoidance is triggered only when measurement reports indicate actual interference conditions exist. This partial application approach prevents unnecessary restrictions on transmission operations, maintaining operating efficiency while providing adequate interference protection when needed
Solution Approach 2:
The system changes operational parameters such as scheduling time periods, frequency selections, and power levels based on measured interference conditions. By dynamically adjusting these parameters rather than imposing fixed restrictions, the system maintains optimal operating efficiency under normal conditions while effectively reducing interference when coexistence problems are detected
Data Source
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AI summary
A method in a wireless terminal supporting operation on a first wireless technology and a second wireless technology comprises performing one or more measurements on a received signal of the first wireless technology, wherein the one or more measurements are performed during time periods that overlap time periods during which the wireless terminal transmits signals of the second wireless technology and the one or more measurements comprise channel state information measurements. The method further comprises transmitting, to a first base station, measurement information comprising the one or more measurements, and sending, to the first base station, an indication of a periodicity of planned transmission by the wireless terminal of signals of the second wireless technology. A method performed in a base station is also disclosed and claimed.