Distributed Antenna Architecture With Digital Self-Interference Suppression
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Solution Overview
Problem
Conventional distributed antenna systems face challenges in effectively isolating downstream and upstream radio frequency signals, leading to self-interference and increased costs due to the use of high-power duplexers, especially in multiple input/multiple output (MIMO) or antenna array applications.
Innovation Solution
The implementation of self-interference suppression processing using feedback signals derived from downstream radio frequency signals, combined with digital signal processing techniques, to reduce self-interference and potentially eliminate the need for high-power duplexers by using low-power duplexers or spatially isolated antennas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If high-power duplexers are used to isolate downstream and upstream radio frequency signals, then signal isolation is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces the mechanical/electrical isolation system (high-power duplexer) with a digital signal processing system. The self-interference suppression is achieved through digital processing of the upstream signal to subtract the downconverted downstream interference, eliminating the need for complex high-power duplexer hardware while maintaining effective signal isolation.
Solution Approach 2:
The patent introduces a downconverter as an intermediary component that converts the downstream radio frequency signal to baseband. This downconverted signal serves as a reference for generating the interference cancellation signal, enabling the digital subtraction of self-interference from the upstream signal path without requiring direct RF isolation.
2Object-affected harmful factors
If high-power duplexers are used to isolate downstream and upstream radio frequency signals, then signal isolation is improved, but cost increases
Solution Approach 1:
The patent replaces the expensive high-power duplexer with lower-cost components including a downconverter and digital signal processing resources. The digital processing implementation using standard baseband processing techniques reduces manufacturing cost while achieving the same self-interference suppression function.
3Object-affected harmful factors
If conventional isolation methods are used, then signal separation is maintained, but system compactness is reduced
Solution Approach 1:
The patent replaces bulky RF isolation hardware with compact digital signal processing. The self-interference suppression is performed in the digital baseband domain, eliminating the need for large physical isolation structures and enabling more compact system design while maintaining effective signal separation.
Data Source
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AI summary
One embodiment is directed to a distributed antenna system comprising a host unit and at least one remote antenna unit that is communicatively coupled to the host unit. The host unit is configured to communicate a downstream transport signal from the host unit to the remote antenna unit. The remote antenna unit to which the downstream transport signal is communicated uses the downstream transport signal to generate a downstream radio frequency signal for radiation from an antenna associated with the remote antenna unit. The remote antenna unit is configured to communicate an upstream transport signal from the remote antenna unit to the host unit, wherein the upstream transport signal is generated from a received upstream radio frequency signal received at the remote antenna unit. The remote antenna unit is configured to perform self-interference suppression processing in an upstream signal path using, as an input thereto, a feedback signal derived from the downstream radio frequency signal radiated from the antenna. Other embodiments are disclosed.