Radio Full Duplex Self-Interference Cancellation
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Solution Overview
Problem
In radio full duplex communications, high-power transmitted signals cause significant self-interference with received signals due to leakage, which complicates simultaneous transmission and reception on the same channel, leading to distortion and interference.
Innovation Solution
A method and system that estimate the channel by transmitting a known signal and its reflection, using a channel estimation module to determine a second signal that cancels out the self-interference component, thereby producing a corrected signal with reduced interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high-power transmitted signals are used for full duplex operation, then transmission efficiency is improved, but self-interference increases
Solution Approach 1:
The patent transmits a known reference signal along with data signals, and uses the reflected known signal to estimate the self-interference channel. This converts the harmful self-interference into a measurable and cancelable component by treating the transmitted signal's reflection as useful information for interference cancellation.
Solution Approach 2:
The system performs channel estimation using the known reference signal before processing the data signal. By determining the self-interference channel characteristics in advance, the system can pre-cancel the self-interference component from the received signal, preventing it from degrading the desired signal reception.
2Productivity
If simultaneous transmission and reception occur on the same channel, then full duplex operation is achieved, but signal leakage increases
Solution Approach 1:
The system uses the reflected known reference signal to estimate the self-interference channel and feeds this channel estimate back to cancel the self-interference from the received signal. This feedback mechanism continuously compensates for signal leakage, enabling clean simultaneous transmission and reception on the same channel.
3Measurement precision
If channel estimation is performed using reflected signals, then self-interference cancellation is improved, but system complexity increases
Solution Approach 1:
The system transmits a known reference signal that serves as a copy of the expected transmitted signal. By comparing the reflected known signal with the original, the system can estimate the self-interference channel without requiring complex measurements, simplifying the overall system while achieving precise interference cancellation.
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 effectively reduces self-interference, maintaining high efficiency in full duplex operations by minimizing the impact on the desired received signal while addressing the challenge of simultaneous transmission and reception.
Implementation Method 1
receiving, by a first radio receiver and the antenna, a reflection of the first signal
Data Source
AI summary
In one embodiment, a method for determining self-interference in radio full duplex includes transmitting, by a first radio transmitter and an antenna, a first signal and receiving, by a first radio receiver and the antenna, a reflection of the first signal. The method also includes estimating a channel in accordance with the first signal and the reflection of the first signal to produce an estimated channel and determining a second signal in accordance with the estimated channel. Additionally, the method includes transmitting, by a second radio transmitter, the second signal and removing a self-interference component of the reflection of the first signal to produce a corrected signal.