Base Station Interference Suppression via Power and Directivity Control

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Solution Overview

Problem

In wireless LANs, adjacent communication cells experience interference due to limited radio resources, leading to degraded transmission rates and throughput, as existing methods struggle to optimally allocate frequency channels and times, and interference suppression using MIMO technology is inefficient due to low channel estimation accuracy.

Innovation Solution

A wireless communication method that employs directivity control and transmission power control to suppress interference between adjacent cells, allowing for increased throughput by calculating and managing interference power effectively, thereby enhancing frequency use efficiency and reducing retransmissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If frequency channel allocation technology is used to avoid interference, then interference is reduced, but transmission rate is degraded due to limited radio resources

Engineering Contradiction:
ImproveinterferenceVSAvoidtransmission rate
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The invention changes the parameter of transmission power dynamically based on detected interference levels. When interference is detected from adjacent cells, the base station adjusts transmission power parameters to suppress interference while maintaining communication quality, thereby improving both interference reduction and transmission rate simultaneously

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention implements dynamic transmission power control where the base station continuously monitors interference levels and adjusts transmission power in real-time. This dynamic adaptation allows the system to optimize the balance between interference suppression and transmission rate according to current channel conditions

Inventive Principle:
Principle #15Dynamics

2Productivity

If MIMO technology is used for interference suppression, then spatial multiplexing is achieved, but channel estimation accuracy is low leading to inefficient interference suppression

Engineering Contradiction:
Improvespatial multiplexing capabilityVSAvoidchannel estimation accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The invention performs preliminary channel estimation using reference signals before actual data transmission. By estimating the channel characteristics in advance and using this information for transmission power control and beamforming, the system overcomes the limitation of low channel estimation accuracy in MIMO systems

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention implements feedback mechanisms where channel estimation results are continuously refined based on received signal quality and interference levels. This feedback loop improves channel estimation accuracy over time, enabling more effective MIMO-based interference suppression

Inventive Principle:
Principle #23Feedback

3Productivity

If transmission power is increased to improve transmission rate, then throughput increases, but interference to adjacent cells increases

Engineering Contradiction:
ImprovethroughputVSAvoidinterference to adjacent cells
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The invention applies local quality by directing transmission energy specifically toward the intended receiver using beamforming techniques. This concentrates the transmission power in the desired direction while minimizing interference to adjacent cells in other directions, thereby achieving high throughput without proportionally increasing interference

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention dynamically changes transmission power parameters based on detected interference levels and channel conditions. By adjusting power allocation adaptively, the system achieves high throughput when channel conditions are favorable while suppressing interference to adjacent cells when necessary

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2547155B1Wireless communication method and base station for suppressing interference
Publication Date: 2019.05.22 NIPPON TELEGRAPH & TELEPHONE CORP
  • EP2547155B1 patent drawingFigure 1
  • EP2547155B1 patent drawingFigure 2
  • EP2547155B1 patent drawingFigure 3

AI summary

Provided are a wireless communication method, a base station, a wireless communication system and a communication apparatus whereby an interference power is calculated from an estimated propagation channel estimation result and the transmission power is controlled based on the interference power or the interference is suppressed by controlling the directivity, thereby increasing the transmission capacity. A propagation channel estimation circuit performs propagation channel estimation from a response signal transmitted from a terminal station and estimates a propagation channel estimation result. An interference power calculation circuit measures each interference power from a signal of each sub-carrier received by each of wireless units, and calculates an interference power for each sub-carrier from the propagation channel estimation result estimated by the propagation channel estimation circuit. When the calculated interference power is equal to or more than a predetermined threshold, an interference suppression signal generation circuit changes the transmission power and generates an interference suppression signal.