Self-Interference Channel Estimation via Zero-Sequence Segmentation

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Solution Overview

Problem

In co-frequency co-time full duplex wireless communication systems, self-interference significantly degrades performance due to poor precision in self-interference channel estimation, which is exacerbated by the presence of wanted signals during estimation processes.

Innovation Solution

A method and device for self-interference channel estimation that involves segmenting service data into multiple segments and inserting a signal sequence of zeros between them, allowing for precise estimation and elimination of self-interference signals by adjusting data structure and using techniques like FFT and ADC to calculate channel values and interference signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional self-interference channel estimation methods (adaptive filtering or pilot-based) are used, then the estimation process can be performed, but the precision of self-interference channel estimation deteriorates when wanted signals are present

Engineering Contradiction:
Improveself-interference channel estimation precisionVSAvoidchannel estimation reliability in presence of wanted signals
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent segments the service data into multiple segments and inserts a signal sequence formed by all zeros between them. This segmentation creates distinct temporal regions where self-interference signals can be estimated without contamination from wanted signals, resolving the contradiction between performing estimation and maintaining precision when wanted signals are present.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a signal sequence formed by all zeros as an intermediary element between service data segments. This intermediary acts as a delimiter that separates self-interference signal components from wanted signal components, enabling precise channel estimation for self-interference without the presence of wanted signals during the estimation process.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If data is segmented into multiple segments with zero sequences inserted, then self-interference channel estimation precision improves, but device complexity increases

Engineering Contradiction:
Improveself-interference channel estimation precisionVSAvoiddata structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides service data into multiple segments with zero sequences inserted between them. This segmentation, while increasing structural complexity, enables precise self-interference channel estimation by creating isolated time regions, thus resolving the trade-off between estimation precision and device complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent modifies the data structure parameters by inserting zero sequences at specific positions between data segments. This parameter change (adding zero sequences) transforms the data structure to enable precise self-interference estimation, accepting the resulting complexity increase as necessary for achieving the measurement precision improvement.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3163821B1Self-interference channel estimation method and device
Publication Date: 2020.05.13 HUAWEI TECH CO LTD
  • EP3163821B1 patent drawingFigure 1~3
  • EP3163821B1 patent drawingFigure 4
  • EP3163821B1 patent drawingFigure 5

AI summary

The present invention discloses a self-interference channel estimation method and device, where the method includes: determining, by a first device when a receive port of the first device receives a first signal, a second signal transmitted by a transmit port of the first device, where the first signal includes a service signal that a second device sends to the first device, and includes a self-interference signal of interference that the second signal transmitted by the transmit port of the first device causes, through an air interface, to the service signal received by the receive port of the first device, where service data included by the second signal is segmented into at least two segments, and a signal sequence formed by at least one preset character is inserted between the at least two segments of service data; estimating, according to the first signal and the second signal, the self-interference signal of interference that the second signal transmitted by the transmit port of the first device causes, through the air interface, to the service signal received by the receive port of the first device; and eliminating the self-interference signal from the received first signal. Interference that the self-interference signal causes to the service signal received by the receive port is effectively suppressed, and system performance is improved.