Coexistence Manager for Multi-Radio Interference Mitigation
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Solution Overview
Problem
Conventional LTE systems face coexistence issues with other radios in multi-radio devices, such as Bluetooth and WLAN, due to interference, leading to unacceptable error rates and disruptions, particularly in the Industrial Scientific and Medical (ISM) band, where existing mechanisms fail to comprehensively address interference and result in inefficient handover decisions and performance degradation.
Innovation Solution
A method and apparatus for determining the time period remaining for an operation by a first radio access technology (RAT) and applying a power backoff to a second RAT based on this time period to mitigate interference, specifically using a coexistence manager to autonomously declare Radio Link Failures and re-establish connections on new channels, and progressively adjusting LTE transmission power to minimize interference with Bluetooth operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If LTE transmissions are performed in the ISM band, then LTE communication functionality is provided, but interference with Bluetooth and WLAN radios occurs leading to unacceptable error rates
Solution Approach 1:
The system performs preliminary actions by detecting coexistence issues between LTE and ISM band radios before they cause unacceptable error rates. The coexistence manager proactively identifies interference patterns and initiates mitigation strategies such as power backoff or channel changes in advance, preventing the degradation of Bluetooth and WLAN communication reliability
Solution Approach 2:
The system changes operational parameters of the LTE radio, specifically transmission power levels and channel selections, to mitigate interference with co-channel ISM band radios. By dynamically adjusting these parameters based on detected interference conditions, the system maintains LTE functionality while reducing harmful effects on Bluetooth and WLAN operations
2Measurement precision
If conventional downlink interference estimation mechanisms are used, then some interference is detected, but uplink coexistence issues are not reflected and unilateral UE actions are thwarted by eNB handover decisions
Solution Approach 1:
The coexistence manager acts as an intermediary layer between the UE's multiple radios and the LTE protocol stack. It receives interference measurements from affected ISM band radios, processes this information, and communicates coexistence issues to the LTE stack through existing measurement report mechanisms. This intermediary function enables the UE to convey uplink interference information to the network without requiring new signaling protocols
Solution Approach 2:
The system implements feedback loops where the coexistence manager continuously monitors interference levels between LTE and ISM band radios, and uses this feedback to dynamically adjust LTE transmission parameters. The manager also provides feedback to the network about coexistence conditions, enabling the eNB to make informed handover decisions that avoid channels with known interference issues
3Productivity
If LTE uplink signal is transmitted on channels adjacent to ISM band, then LTE data transmission is enabled, but interference with Bluetooth and WLAN signals occurs
Solution Approach 1:
The system dynamically adjusts LTE transmission parameters including power levels and channel selections based on real-time detection of coexistence issues. The coexistence manager continuously monitors interference conditions and modifies LTE uplink transmissions accordingly, creating a dynamic adaptation mechanism that balances data transmission needs with interference mitigation requirements
Data Source
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AI summary
In a multi-radio user equipment, a power backoff or similar restraint may be placed on communications of a first radio, such as LTE, in order to protect operations of a second radio, such as Bluetooth, depending on the time remaining for completion of the communications of the second radio. Such protected operations may include paging or inquiry operations. A power backoff may be applied to an LTE radio in order to protect completion of the paging or inquiry operations. The power backoff may be increased as the time to completion of the paging or inquiry operations approaches.