Full Duplex Self-Interference Cancellation via Phase Compensation
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Solution Overview
Problem
Full duplex communication systems face significant performance deterioration due to intra-device self-interference, which needs to be effectively canceled to operate efficiently.
Innovation Solution
A communication device with a baseband unit comprising a first and second transmission chain, a distributed radio unit configured for phase compensation, and a self-interference cancellation unit that calculates and applies a phase coefficient value to cancel self-interference signals, utilizing an idle transmission module in a distributed antenna structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If full duplex communication is implemented to double system capacity, then system capacity is improved, but intra-device self-interference deteriorates performance
Solution Approach 1:
The patent transmits the uplink signal through the second Tx chain to generate a self-interference cancellation signal. By reusing the existing uplink signal and transmitting it through the same hardware path (second Tx chain), the system creates a precise copy of the self-interference signal that can be subtracted from the received signal, converting the harmful self-interference into a beneficial cancellation mechanism
Solution Approach 2:
The patent introduces a phase compensator as an intermediary component between the baseband unit and the second distributed RU. This phase compensator processes the uplink signal to apply phase compensation before transmission through the second Tx chain, enabling accurate generation of the cancellation signal that accounts for phase changes in the self-interference path
2Measurement precision
If phase compensation is applied using a phase compensator, then self-interference cancellation accuracy is improved, but device complexity increases
Solution Approach 1:
The patent makes the second Tx chain serve multiple functions: its primary function is to transmit downlink signals, but it is also configured to transmit uplink signals for self-interference cancellation purposes. This multi-functionality allows the system to generate accurate cancellation signals without adding dedicated hardware, reducing overall device complexity while maintaining phase compensation accuracy
Solution Approach 2:
The system uses its own existing hardware resources (second Tx chain) to generate the self-interference cancellation signal. By making the second Tx chain available for dual purposes and using the uplink signal itself as the source for cancellation, the system achieves accurate phase compensation without requiring external or additional specialized components
Data Source
AI summary
A communication device for performing magnetic interference cancellation comprises: a baseband unit including a first transmission chain and a second transmission chain; a first distributed radio unit (RU) connected to the first transmission chain and set to a transmit (Tx) mode; and a second distributed RU connected to the second transmission chain and set to a receive (Rx) mode, wherein the baseband unit includes a phase correction unit, connected to the first transmission chain and the second transmission chain, for performing phase correction for the magnetic interference cancellation on a signal transmitted from the first transmission chain, and the second transmission chain is configured to transmit a signal output from the phase correction unit to the second distributed RU, the second distributed RU uses a signal that was output from the phase correction unit and has passed through the second transmission.