Non-Duplexer Telecommunications Architecture Using Direct RF Sampling
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Solution Overview
Problem
Distributed antenna systems (DAS) face challenges in isolating uplink signals from downlink signals without the use of a duplexer, which limits flexibility in responding to changes in frequency band allocation and introduces spurious responses due to down-conversion requirements.
Innovation Solution
The implementation of a telecommunications system using high dynamic range analog-to-digital converters in an active mitigation subsystem allows for direct sampling and conversion of RF signals, eliminating the need for down-conversion and enabling the use of a power combiner to couple uplink and downlink communication paths to an antenna, thereby reducing spurious responses and relaxing isolation requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a duplexer is used to isolate uplink and downlink signals, then signal isolation is improved, but device complexity and inflexibility increase
Solution Approach 1:
The patent extracts the down-conversion function from the signal path by using direct RF-to-digital conversion. The ADC directly converts RF signals to digital domain without requiring analog down-conversion stages, removing the need for duplexers and associated isolation components while maintaining signal integrity through digital signal processing.
Solution Approach 2:
The patent replaces the mechanical/analog isolation system (duplexer with physical isolation components) with a digital isolation approach. Digital signal processing in the digital domain provides signal separation and isolation without requiring complex physical isolation hardware, thereby reducing device complexity while maintaining reliability.
2Ease of operation
If down-conversion is used to process RF signals, then signal processing capability is improved, but spurious responses increase
Solution Approach 1:
The patent substitutes analog down-conversion with direct RF-to-digital conversion using high-performance ADCs. This eliminates the analog mixing process that generates spurious responses, while digital signal processing maintains full signal processing capability in the digital domain where spurious responses can be more effectively managed.
Solution Approach 2:
The patent changes the operating parameters of signal conversion by using ADCs with sufficiently high sampling rates and dynamic range to directly handle RF signals. This parameter change enables direct RF digitization without down-conversion, eliminating the generation of spurious responses while preserving signal processing capabilities through digital techniques.
3Object-generated harmful factors
If strict isolation between uplink and downlink paths is implemented, then interference is reduced, but system stability requirements increase
Solution Approach 1:
The patent extracts the signal separation function from the physical domain to the digital domain. By converting signals to digital form before processing, the system achieves interference reduction through digital signal processing techniques rather than requiring strict physical isolation, thereby reducing system stability requirements while maintaining interference rejection.
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 reduces the need for strict isolation between uplink and downlink signals, preventing system instability and spurious interference, and allows for flexible frequency band management without the need for duplexers, enhancing the reliability and efficiency of DAS.
Implementation Method 1
high dynamic range analog-to-digital converters in an active mitigation subsystem allows for direct sampling and conversion of RF signals
Data Source
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AI summary
A telecommunications system can include analog-to-digital converters in an uplink communication path or a downlink communication path. The analog-to-digital converters can have a high dynamic range and bandwidth to obviate a need for down-conversion of signals using an analog mixer. The uplink communication path and the downlink communication path can be coupled to an antenna using a non- duplexer coupling device. Uplink signals traversing the uplink communication path can be isolated from downlink signals independent of using a duplexer.