Dual Connectivity Intermodulation Sensitivity Management
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Solution Overview
Problem
The use of higher frequency bands in 5G systems for dual connectivity with LTE can result in intermodulation products that degrade receiver sensitivity, particularly with certain combinations of LTE/5G band/RF carrier combinations, leading to unacceptable levels of sensitivity degradation and potential interference.
Innovation Solution
A method where a user equipment (UE) initially establishes a primary LTE uplink carrier for control-plane messaging and user-plane communications, and upon request, attempts to establish a secondary 5G uplink carrier, with the core network adapting its behavior based on feedback from the UE regarding sensitivity degradation and power requirements to optimize performance, potentially switching to time division multiplexing or using single LTE or parallel LTE/5G carriers to mitigate intermodulation effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If higher frequency bands are used for 5G dual connectivity with LTE, then bandwidth and capacity are improved, but intermodulation products degrade receiver sensitivity
Solution Approach 1:
The patent implements dynamic selection between simultaneous transmission mode and time division multiplexing mode based on real-time assessment of intermodulation distortion levels. The system transitions from a static frequency allocation approach to a dynamic one where the transmission mode adapts to current channel conditions, UE capabilities, and interference levels, thereby optimizing both bandwidth utilization and receiver sensitivity maintenance.
Solution Approach 2:
The system changes operational parameters including transmission mode (simultaneous vs. TDM), frequency band selections, and power allocation based on UE feedback regarding intermodulation distortion tolerance. By adjusting these parameters dynamically, the network can maintain acceptable receiver sensitivity while utilizing higher frequency bands for increased capacity.
2Productivity
If simultaneous LTE and 5G uplink transmissions are used, then productivity is improved, but intermodulation distortion increases causing sensitivity degradation
Solution Approach 1:
The system dynamically switches between simultaneous transmission mode (for high productivity when interference is low) and time division multiplexing mode (when intermodulation distortion becomes problematic). This dynamic adaptation allows the system to maximize data transmission rates while maintaining signal quality by avoiding sustained operation in the presence of harmful intermodulation products.
Solution Approach 2:
When operating in time division multiplexing mode, the system employs periodic alternating transmissions between LTE and 5G uplinks rather than continuous simultaneous transmission. This periodic separation eliminates intermodulation distortion while maintaining overall productivity through efficient time-multiplexed resource utilization.
3Productivity
If a specific LTE/5G band combination is selected for dual connectivity, then capacity is improved, but receiver sensitivity degrades due to intermodulation products
Solution Approach 1:
The system changes frequency band parameters and transmission mode parameters based on UE feedback about intermodulation distortion characteristics. When a particular LTE/5G band combination causes sensitivity degradation, the network can switch to alternative band combinations or adjust power allocation, thereby maintaining network capacity while preserving receiver sensitivity through parameter optimization.
Solution Approach 2:
The UE provides feedback regarding its ability to tolerate intermodulation distortion from specific band combinations. The network uses this feedback to make informed decisions about which LTE/5G band combinations to deploy for dual connectivity, enabling data-driven optimization of both capacity and sensitivity by selecting band combinations that the UE can handle effectively.
Data Source
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AI summary
A mobile communication device is configured to implement dual connectivity, using both a Long-Term Evolution (LTE) radio and a 5th-Generation (5G) radio, for communicating with respective base stations of a cellular network. A primary transmission uplink is established in a first radio frequency band using the LTE radio. The device may then receive a request to establish a secondary transmission uplink in a second frequency band. Upon receiving the request, the device determines whether it can support concurrent use of the primary and secondary frequency bands while maintaining adequate receiver sensitivity. If the device cannot support such concurrent use, the device refuses the request. In addition, the device provides data indicating the degree by which certain performance parameters would be out-of-tolerance if the secondary connection were to be established.