Asynchronous Wireless Interference Mitigation via Reserved Pilots

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Solution Overview

Problem

Wireless communication networks face significant interference issues due to asynchronous operations between base stations and terminals, leading to degraded performance in both downlink and uplink transmissions.

Innovation Solution

The implementation of interference mitigation techniques, including reserved control resources and pilot channels, allows terminals and base stations to request and adjust transmit power levels and beamsteering to reduce interference, using asynchronous control and pilot channels to coordinate interference reduction across asynchronous networks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If base stations and terminals operate asynchronously to provide flexible wireless communication, then network adaptability and coverage are improved, but interference between transmissions increases and performance degrades

Engineering Contradiction:
Improvenetwork adaptabilityVSAvoidinterference
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary actions by sending control signals and pilot channels before actual data transmission. The serving base station sends a control signal to the interfering base station in advance, requesting interference mitigation. Pilot channels are transmitted beforehand to enable channel estimation and quality measurement, allowing the system to prepare for and coordinate interference reduction before the harmful interference occurs during data transmission.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements feedback mechanisms where the serving base station measures channel quality using pilot channels and sends this information back to the interfering base station. The interfering base station uses this feedback to adjust its transmission parameters (power, beamforming) to reduce interference. This closed-loop feedback enables dynamic adaptation to changing interference conditions while maintaining asynchronous operation.

Inventive Principle:
Principle #23Feedback

2Reliability

If transmit power is increased to improve signal quality, then data transmission reliability is improved, but interference to other transmissions increases

Engineering Contradiction:
Improvedata transmission reliabilityVSAvoidinterference
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The system dynamically changes transmission parameters based on channel conditions and interference measurements. The interfering base station adjusts its transmit power level, beamforming weights, or both, in response to control signals from the serving base station. This parameter adaptation allows the system to maintain reliable data transmission when needed while reducing interference when other transmissions are active, resolving the contradiction between reliability and interference generation.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If interference mitigation techniques are implemented, then signal-to-noise-and-interference ratio is improved, but system complexity increases

Engineering Contradiction:
Improvesignal-to-noise-and-interference ratioVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system segments the interference mitigation process into distinct functional components: pilot channel transmission for channel estimation, control signal exchange for coordination, and separate data transmission phases. This segmentation allows each component to be optimized independently and simplifies the overall system architecture by breaking down the complex interference mitigation task into manageable, standardized steps that can be implemented using existing wireless communication protocols.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2274945B1Short-term interference mitigation in an asynchronous wireless network
Publication Date: 2019.02.06 QUALCOMM INC
  • EP2274945B1 patent drawingFigure 1
  • EP2274945B1 patent drawingFigure 2
  • EP2274945B1 patent drawingFigure 3

AI summary

Techniques for mitigating interference in an asynchronous wireless network are described. A terminal may desire to communicate with a serving base station and may observe high interference from other base stations. In an aspect, some frequency resources may be reserved for sending reduce interference requests and pilots to support interference mitigation. In one design, a first station (e.g., a terminal) may send a request to reduce interference to at least one interfering station on reserved control resources. The first station may receive a pilot sent by each interfering station on reserved pilot resources. The reserved resources may be associated with data resources. The first station may estimate received signal quality of the data resources based on the pilot(s). The first station may receive data sent on the data resources by a second station (e.g., a serving base station) after the interfering station(s) have reduced interference.