IBFD Transceiver Non-Reciprocal Frequency Transposition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In-Band Full-Duplex communication systems face high self-interference due to circulator leakage and antenna unsuitability, leading to complex architectures and reduced receive signal levels, which existing echo cancellation methods partially address but at the cost of increased complexity.
Innovation Solution
A transceiver design incorporating a non-reciprocal frequency transposition module that separates transmit and receive channels by a predetermined frequency difference, using a duplexer and bidirectional frequency transposition module with in-phase and quadrature branches, and power splitters/combiners to achieve effective isolation between channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If echo cancellation is used to reduce self-interference, then self-interference level is reduced, but device complexity increases
Solution Approach 1:
The patent applies parameter changes by frequency transposition, shifting the transmit signal to a different frequency band than the receive signal. This frequency separation parameter change inherently reduces self-interference without requiring complex echo cancellation processing, thus resolving the contradiction between interference reduction and complexity increase.
Solution Approach 2:
The patent extracts the interfering transmit signal from the receive band by using frequency transposition to move it to a separate frequency band. This extraction of the harmful interference component through frequency domain separation simplifies the overall system compared to time-domain or signal-processing-based echo cancellation methods.
2Object-affected harmful factors
If frequency division duplexing is used to separate transmit and receive frequencies, then self-interference is reduced, but spectral efficiency decreases
Solution Approach 1:
The patent segments the frequency spectrum by transposing the transmit signal to a specific frequency band that is separated from the receive band by a guard band. This segmentation approach provides interference isolation while maintaining efficient spectrum utilization, achieving a balance between self-interference reduction and spectral efficiency that pure FDD does not provide.
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 solution simplifies the transceiver structure while achieving good isolation between transmit and receive channels, reducing self-interference and maintaining spectral efficiency, similar to FDD systems, with the advantages of IBFD communication.
Implementation Method 1
said frequency transposition module being suitable for transposing the signal to be transmitted (STXin) by a predetermined frequency difference, ΔF, to obtain the transmit signal (STXout), and for transposing by the same frequency difference, the receive signal SRXin) in order to obtain the received signal (SRXout)
Data Source
AI summary
A transceiver for In-Band Full-Duplex communication is provided. The transceiver includes a duplexer and a bidirectional frequency transposition module, the frequency transposition module being suitable for transposing a signal to be transmitted, with a predetermined frequency shift, ΔF, in order to obtain a transmit signal, and for transposing the receive signal, with the same frequency shift, in order to obtain the received signal, with the frequency band of the signal to be transmitted and the frequency band of the received signal thus being separated by a frequency shift which is double the predetermined frequency shift.