Antenna Configuration Switching for Full-Duplex Isolation
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Solution Overview
Problem
Full-duplex radio transmission on the same carrier frequency faces challenges in achieving sufficient isolation between the transmitting and receiving branches, which affects channel reciprocity and performance, especially in MIMO technologies.
Innovation Solution
The method involves switching between antenna configurations to alternately use antennas for incoming and outgoing signals, allowing for channel reciprocity considerations in channel estimation and achieving isolation between the transmit and receive branches, using reference signals for accurate channel characterization and controlling multi-antenna transmission configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If separate antennas are used for transmit and receive branches to achieve sufficient isolation, then isolation between branches is improved, but channel reciprocity is adversely affected
Solution Approach 1:
The patent dynamically switches between different antenna configurations (first configuration with first antenna for transmit and second antenna for receive, second configuration with second antenna for transmit and first antenna for receive) based on channel conditions. This dynamic adaptation allows the system to maintain channel reciprocity while achieving sufficient isolation through cross-talk cancellation algorithms that exploit the known antenna configuration state.
Solution Approach 2:
The system changes the antenna configuration parameters between transmit and receive operations, alternating which antenna is used for which function. This parameter switching enables the system to maintain reciprocity assumptions valid for channel estimation while still achieving the necessary isolation through coordinated switching and cross-talk cancellation.
2Reliability
If the same antenna is used for both transmit and receive to maintain channel reciprocity, then channel reciprocity is improved, but isolation between branches deteriorates
Solution Approach 1:
The patent introduces cross-talk cancellation algorithms as an intermediary mechanism that processes the signals to remove self-interference. By using these algorithms in conjunction with antenna configuration switching, the system can effectively isolate transmit and receive paths while maintaining the reciprocity needed for accurate channel estimation, as the cancellation process exploits the known antenna switching pattern.
Solution Approach 2:
The dynamic switching between antenna configurations creates time-varying channel characteristics that the cross-talk cancellation algorithm can exploit. By alternating antenna assignments and coordinating this switching with signal processing, the system maintains reciprocity during each configuration state while achieving isolation through the coordinated dynamic behavior.
3Object-affected harmful factors
If antenna configurations are switched frequently to maintain isolation, then isolation is improved, but device complexity increases
Solution Approach 1:
The patent makes the antenna system multi-functional by allowing each antenna to serve both transmit and receive functions at different times. This universal usage of antennas eliminates the need for dedicated transmit and receive antenna sets, reducing hardware complexity while maintaining isolation through coordinated switching and cross-talk cancellation algorithms.
Solution Approach 2:
The antenna configuration switching follows a periodic or coordinated pattern that synchronizes with the communication protocol. This periodic switching behavior simplifies control logic compared to arbitrary switching, as the system can predict and prepare for configuration changes at regular intervals, reducing the complexity of real-time control.
Data Source
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AI summary
A radio device transmits outgoing radio signals (20) on a carrier frequency to a further radio device and receives incoming radio signals (30) on the same carrier frequency from the further radio device. The radio device switches at least between a first antenna configuration and a second antenna configuration, e.g., by means of a switch (330). In the first antenna configuration, the outgoing radio signals (20) are transmitted via at least one first antenna (340) while simultaneously the incoming radio signals are received via at least one second antenna (350). In the second antenna configuration, the outgoing radio signals (20) are transmitted via the at least one second antenna (350) while simultaneously the incoming radio signals (30) are received via the at least one first antenna (340).