Multi-Frequency Access Node Selection for Intermodulation Mitigation
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Solution Overview
Problem
Wireless communication networks face inefficiencies in mitigating intermodulation interference when multiple radio frequencies are handled by shared antenna circuitry, leading to interference with legitimate radio frequencies used by other access nodes.
Innovation Solution
A wireless communication network system that identifies potential intermodulation interference by determining Nyquist products and spectral distances, selects a qualifying set of secondary access nodes based on signal strengths and communication performance, and efficiently mitigates interference by transferring user data through a serving set of secondary access nodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple wireless access nodes use different radio frequencies on the same tower with shared antenna circuitry, then wireless data services can be provided to multiple user devices simultaneously, but intermodulation interference occurs that interferes with legitimate radio frequencies used by other access nodes
Solution Approach 1:
The system performs preliminary calculation of Nyquist products for candidate secondary access nodes before final selection. By computing potential intermodulation interference in advance and comparing spectral distances, the system identifies and excludes problematic frequency combinations before they cause harmful interference, thus preventing the issue rather than reacting to it
Solution Approach 2:
The patent introduces an intermediary selection process that acts between the candidate set of secondary access nodes and the final serving set. This intermediary mechanism evaluates spectral distances and filters out nodes that would create intermodulation interference, allowing the system to maintain productive multi-frequency operations while eliminating harmful interference through a mediating selection layer
2Adaptability or versatility
If shared antenna circuitry handles multiple radio frequencies at the same time, then multiple wireless access nodes can operate from the same tower, but non-linearities in the circuitry generate intermodulation interference
Solution Approach 1:
The system calculates Nyquist products and evaluates spectral distances before finalizing the selection of secondary access nodes. This preliminary action identifies frequency combinations that would exploit the non-linearities of shared antenna circuitry to generate harmful intermodulation products, allowing the system to avoid these combinations while maintaining multi-frequency versatility
Solution Approach 2:
The patent changes the selection parameters for secondary access nodes from purely signal-strength-based to include spectral distance metrics. By modifying the selection criteria to account for potential intermodulation interference, the system adapts its operation to the non-linear characteristics of shared antenna circuitry, ensuring that frequency parameters are chosen to minimize harmful interactions
3Productivity
If the system selects secondary access nodes based solely on signal strength, then user data transfer efficiency is maximized, but intermodulation interference with other access nodes increases
Solution Approach 1:
The system performs preliminary evaluation of spectral distances between candidate secondary access node frequencies and potential Nyquist products before selecting the final serving set. This preliminary filtering ensures that high-signal-strength nodes are selected only when they won't cause harmful interference, thus maintaining data transfer efficiency while preventing interference with other legitimate radio frequencies
Solution Approach 2:
The patent implements a feedback mechanism where the selection of secondary access nodes considers the spectral environment and potential intermodulation products. The system effectively feeds back information about frequency interference potential into the selection process, adjusting node selection to balance signal strength advantages against interference avoidance, thereby maintaining both productivity and spectral compatibility
Data Source
AI summary
A wireless communication network delivers multi-frequency service to User Equipment (UE). A primary node receives signaling from the UE that indicates secondary nodes along with their frequencies and signal strengths. The primary node selects candidate nodes based on the signal strengths for the secondary nodes. The primary node determines potential intermodulation interference between the primary frequency and the frequencies for the candidate set. The primary node selects a qualifying set from the candidate set based on the potential intermodulation interference. The primary node determines communication performance for the qualifying set and selects a serving set from the qualifying set based on the communication performance. The primary node wirelessly transfers signaling to the UE identifying the serving set and transfers signaling to the serving set identifying the UE. The serving set of secondary access nodes wirelessly transfer user data to the UE over their frequencies responsive to the signaling.