Beam Nulling for Wide-Area and Terrestrial Cell Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Interference between terrestrial and upper airspace communication systems using the same frequency band reduces the throughput of both systems, necessitating a method to suppress residual interference when forming a directional beam from a relay communication station in the upper airspace towards a terrestrial cell base station.
Innovation Solution
A communication system with a wide-area cell base station and plural terrestrial cell base stations performing time-synchronized service link communications, using beamforming to form nulls towards terrestrial cell base stations based on uplink and downlink conditions, and adjusting null forming methods for different communication directions and resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a directional beam with null is formed from the relay communication station toward the terrestrial cell base station to suppress interference, then interference to the terrestrial system is reduced, but residual interference remains that further reduces throughput
Solution Approach 1:
The patent applies dynamics by making the null forming method adjustable and adaptive based on communication conditions. The system dynamically selects between different null forming methods (single null, multiple nulls, null sweeping) depending on whether uplink and downlink communication directions are the same or different, thereby optimizing interference suppression while maintaining throughput under varying operational conditions
Solution Approach 2:
The patent changes the parameter of beamforming configuration by selecting different null forming methods based on communication conditions. When uplink and downlink directions differ, a single null method is used; when they are the same, multiple null or null sweeping methods are applied. This parameter adaptation resolves the contradiction by optimizing the balance between interference suppression and throughput maintenance
2Device complexity
If a single null is formed toward the terrestrial cell base station, then device complexity is reduced, but residual interference cannot be sufficiently suppressed
Solution Approach 1:
The system dynamically adjusts the complexity of beamforming control by selecting different null forming methods based on communication conditions. When uplink and downlink directions are different, a simpler single null method is used. When directions are the same, more complex methods (multiple nulls or null sweeping) are applied to achieve sufficient interference suppression. This dynamic adaptation resolves the contradiction between complexity and interference suppression effectiveness
3Object-affected harmful factors
If null sweeping is performed to reduce residual interference, then interference suppression is improved, but communication quality may deteriorate due to increased interference in certain directions
Solution Approach 1:
The system dynamically selects whether to apply null sweeping based on the communication conditions. Null sweeping is applied when uplink and downlink directions are the same, providing superior interference suppression. When directions differ, a simpler single null method is used to avoid potential communication quality deterioration. This conditional application resolves the contradiction between interference suppression and communication quality
Solution Approach 2:
The patent changes the beamforming parameter configuration by selecting different null forming methods based on communication conditions. The system adapts the null forming approach (single null, multiple nulls, or null sweeping) according to whether uplink and downlink directions match, thereby optimizing the balance between residual interference reduction and communication quality maintenance
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Reduces residual interference by optimizing beamforming to minimize interference between terrestrial and upper airspace systems, maintaining communication quality and throughput in both systems.
Implementation Method 1
controls a beamforming by the service link antenna of the relay communication station so as to form a null toward within a coverage area of the terrestrial cell base station
Implementation Method 2
form a null toward within a coverage area of the terrestrial cell base station based on the null forming method
Data Source
AI summary
Provided is a system capable of reducing a residual interference when forming a null of a directional beam from a relay communication station in an upper airspace which forms a wide-area cell toward an antenna of a terrestrial cell base station. The wide-area cell base station and one or plural terrestrial cell base stations perform service link communications in the same frequency band using radio frames that are time-synchronized with each other. The wide-area cell base station determines a null-forming method according to the conditions of uplink (UL) and downlink (DL) of the service link communications that are performed synchronously in the radio frames of the wide-area cell and the terrestrial cell, and controls a beamforming by the service link antenna of the relay communication station so as to form a null toward within a coverage area of the terrestrial cell base station based on the null-forming method.