Full-Duplex Terminal Self-Interference Cancellation

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Solution Overview

Problem

Co-time, co-frequency full-duplex technology faces challenges in suppressing strong self-interference signals in wireless communication systems, which limits the potential for doubling transmission rates and efficient spectrum utilization.

Innovation Solution

A co-time, co-frequency full-duplex terminal and system that employs a central processor, radio frequency transceiver, power divider, power amplifier, controllable adaptive module, signal mixer, and local antennas to divide and process radio frequency signals, ensuring the sampling signal has equal amplitude and opposite phase to the self-interference signal, allowing for effective mixing and suppression of self-interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If co-time co-frequency full-duplex technology is implemented to double transmission rate, then spectrum utilization and transmission efficiency are improved, but strong self-interference signal is generated that limits system performance

Engineering Contradiction:

Improvetransmission rateVSAvoidself-interference signal

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary anti-action by generating a counter-signal with equal amplitude and opposite phase to the self-interference signal before it reaches the receiver. The controllable adaptive module pre-processes the transmitted signal to create an anti-phase cancellation signal that neutralizes the self-interference, allowing full-duplex operation without performance degradation from interference

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The patent converts the harmful self-interference signal into a beneficial cancellation mechanism. By sampling the transmitted signal, processing it through the controllable adaptive module to invert its phase, and then combining it with the received signal, the system transforms the harmful interference into a useful cancellation process that enables simultaneous transmission and reception

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Object-affected harmful factors

If self-interference suppression is implemented using traditional methods, then some interference reduction is achieved, but the self-interference signal cannot be completely offset and performance is limited

Engineering Contradiction:

Improveself-interference signalVSAvoidinterference suppression performance

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the amplitude and phase parameters of the cancellation signal through the controllable adaptive module. The module modifies these parameters in real-time to precisely match the self-interference characteristics, enabling complete offset of the interference signal and achieving ideal suppression performance

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback by sampling the transmitted signal, processing it through the controllable adaptive module, and combining it with the received signal in a closed-loop manner. The system continuously monitors and adjusts the cancellation signal parameters based on the actual self-interference conditions, ensuring optimal suppression performance

Inventive Principle:

Principle #23Feedback

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

This approach significantly enhances self-interference suppression, enabling improved performance and efficiency in co-time, co-frequency full-duplex communication systems by ensuring the self-interference signal is completely offset, thereby achieving the objective of doubling transmission rates under the same conditions.

Implementation Method 1

a phase thereof is processed to be shifted by the controllable adaptive module, so that the sampling signal has an amplitude same as and a phase opposite to a self-interference signal

Methodology Applied

Scientific EffectPhase shift:

Implementation Method 2

transmitted to the signal mixer to be mixed with a base station signal and the self-interference signal which are received by the local receiving antenna

Methodology Applied

Scientific EffectSignal mixing:

Implementation Method 3

a radio frequency signal in one path is outwardly transmitted by the local transmitting antenna after being amplified by the power amplifier

Methodology Applied

Scientific EffectPower amplification:

Data Source

PatentUS10291381B2Co-time, co-frequency full-duplex terminal and system

Publication Date: 2019.05.14 HUIZHOU TCL MOBILE COMM CO LTD

AI summary

A co-time, co-frequency full-duplex terminal includes a radio frequency transceiver, a power divider, a local transmitting antenna, a controllable adaptive module, and a signal mixer. The radio frequency transceiver transmits a radio frequency signal. The power divider divides the radio frequency signal into radio frequency signals in a first path and a second path. The local transmitting antenna transmits the radio frequency signal in the first path. The controllable adaptive module controls the radio frequency signal in the second path to have an amplitude equal to an amplitude of a self-interfere signal and have a phase opposite to a phase of the self-interference signal. The signal mixer mixes the radio frequency signal, after being controlled by the controllable adaptive module, with a base station signal and the self-interference signal.