Uplink Frequency Layout Switching for Interference Mitigation
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Solution Overview
Problem
Modern wireless communication standards face challenges with signal amplitude and phase distortions due to nonlinearity in transmitter devices, leading to signal spectral regrowth and interference with adjacent channels, particularly in uplink transmissions, which are exacerbated by high Peak-to-Average Power Ratio (PAPR) in OFDM signals, causing inefficient power amplifier operation and interference.
Innovation Solution
An apparatus and method that define different prioritized frequency layouts, verify appropriate radio conditions for reference signal waveform emission and power class boosting, and initiate signaling to redirect uplink service traffic to minimize interference by optimizing power amplifier operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If highly linear power amplifier properties are used to avoid interference with adjacent channels, then interference with adjacent channels is reduced, but power amplifier efficiency deteriorates
Solution Approach 1:
The patent implements dynamic frequency layout adaptation where the system continuously monitors uplink interference conditions and switches between different prioritized frequency layouts (e.g., layout A, B, C) based on current radio conditions. This dynamic approach allows the power amplifier to operate efficiently in its nonlinear region while the system adaptively manages spectral regrowth by selecting frequency layouts that minimize adjacent channel interference for the current traffic conditions.
Solution Approach 2:
The system changes operational parameters by switching between different frequency layouts and adjusting the prioritization of different service types (eMBB, URLLC, mMTC) based on interference conditions. The network can dynamically adjust which frequency resources are allocated to which services, and modify power back-off levels, thereby optimizing the trade-off between power amplifier efficiency and adjacent channel interference without requiring the PA to operate in a highly linear but inefficient mode.
2Use of energy by moving object
If power amplifier operates in nonlinear region to improve efficiency, then power amplifier efficiency is improved, but signal spectral regrowth occurs
Solution Approach 1:
The patent segments the uplink frequency spectrum into multiple prioritized frequency layouts with different service allocations. By dividing the spectrum into distinct frequency resources for different services (e.g., frequency layout A for eMBB, layout B for URLLC, layout C for mMTC), the system can manage spectral regrowth on a per-service basis. When spectral regrowth occurs in one frequency layout, the system can redirect affected services to alternative frequency layouts, thereby containing the harmful effects of spectral regrowth while allowing the power amplifier to operate efficiently in its nonlinear region.
3Object-affected harmful factors
If uplink power back-off is increased to reduce interference, then adjacent channel interference is reduced, but cell coverage deteriorates
Solution Approach 1:
The system dynamically adjusts power back-off levels based on real-time interference conditions and service priorities. Instead of applying a fixed high power back-off that would uniformly reduce cell coverage, the system can apply selective power back-off only when and where adjacent channel interference becomes problematic, while maintaining normal power levels for services that are less sensitive to interference or that are prioritized in the current conditions. This dynamic power control preserves cell coverage while reducing interference when necessary.
Solution Approach 2:
The patent applies different power control strategies to different frequency layouts and service types based on their specific requirements. Critical services like URLLC may receive preferential treatment with lower power back-off and higher priority frequency allocations, while less critical services may tolerate higher power back-off. This localized quality approach ensures that cell coverage is maintained for services that require it, while power back-off is applied selectively to reduce adjacent channel interference for services that can tolerate it.
4Object-affected harmful factors
If frequency layout is changed to mitigate interference, then adjacent channel interference is reduced, but signaling overhead increases
Solution Approach 1:
The patent pre-configures multiple prioritized frequency layouts (layout A, B, C, etc.) with different service allocations and interference characteristics before interference problems occur. These frequency layouts are prepared in advance and stored in the network. When adjacent channel interference is detected, the system can immediately switch to a pre-configured alternative frequency layout without requiring complex real-time calculations or extensive signaling exchanges. This preliminary preparation significantly reduces the signaling overhead associated with interference mitigation, as the system only needs to signal a simple layout selection rather than negotiating new frequency allocations from scratch.
Data Source
AI summary
An apparatus is disclosed, including at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to define different prioritized frequency layouts for uplink signal interference handling, verify first radio conditions for enabling most appropriate uplink reference signal waveform emission, verify second radio conditions for signalling lower allowed uplink power back-off and uplink maximum output power class boosting, and, based on the verifying, initiate signalling to mitigate uplink signal interference by redirecting uplink service traffic to a most appropriate prioritized frequency layout.