Hybrid Expansion Unit for Analog-Digital Signal Conversion in DAS
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Solution Overview
Problem
Distributed Antenna Systems (DAS) face challenges in providing reliable and efficient wireless coverage in substantially closed environments due to limitations in signal transport and synchronization between digital and analog domains, leading to issues with signal loss and distortion over long distances.
Innovation Solution
A hybrid expansion unit and method for communicating within a hybrid communication system that uses both digital and analog transport to extend wireless coverage, employing a master host unit, hybrid expansion units, and analog remote antenna clusters, with time division duplexing (TDD) communication links to synchronize and convert RF signals, ensuring accurate conversion and recovery between analog and digital spectra.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If digital and analog transport are used separately in DAS, then signal transport capability is improved, but synchronization between domains deteriorates
Solution Approach 1:
The patent combines digital and analog transport domains into a unified hybrid DAS architecture. Digital transport handles baseband signals with precise synchronization, while analog transport carries RF signals over long distances. The hybrid expansion unit merges these domains by converting digital baseband signals to analog RF signals and vice versa, maintaining synchronization through shared clock references and coordinated timing mechanisms across both transport modes.
Solution Approach 2:
The hybrid expansion unit acts as an intermediary between digital and analog transport domains. It includes digital-to-analog converters (DACs) and analog-to-digital converters (ADCs) that bridge the two domains, along with clock synchronization mechanisms that coordinate timing. This intermediary ensures seamless signal transition and maintains synchronization accuracy despite the fundamental differences between digital and analog transport characteristics.
2Area of stationary object
If signal transport distance is increased in DAS, then coverage area is improved, but signal loss and distortion worsen
Solution Approach 1:
The patent segments the DAS into multiple hierarchical levels: master expansion units, hybrid expansion units, and remote antenna units distributed throughout the coverage area. Each segment operates semi-independently with local signal regeneration and amplification capabilities. This segmentation allows signals to be refreshed at intermediate points, extending total coverage distance while maintaining signal quality by preventing cumulative loss and distortion over long transport paths.
Solution Approach 2:
The system employs dynamic signal adjustment mechanisms including variable gain amplifiers, adaptive equalization, and real-time quality monitoring. These dynamic elements automatically adjust signal parameters based on transport distance and channel conditions, compensating for signal loss and distortion as signals traverse longer distances to extend coverage while maintaining acceptable signal quality.
3Adaptability or versatility
If hybrid expansion unit is introduced in DAS, then signal conversion capability is improved, but device complexity worsens
Solution Approach 1:
The hybrid expansion unit is designed as a universal component that performs multiple functions: digital-to-analog conversion, analog-to-digital conversion, signal amplification, clock synchronization, and protocol translation. By consolidating these diverse functions into a single multi-functional unit, the system achieves high adaptability for different transport scenarios while avoiding the need for multiple specialized devices that would increase overall system complexity.
Data Source
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AI summary
A communication system includes a master host unit that communicates wireless spectrum with a service provider interface using analog spectrum. Master host unit communicates digitized spectrum in N-bit words over a digital communication link. Master host unit converts between analog spectrum and N-bit words of digitized spectrum. Communication system includes hybrid expansion unit coupled to master host unit by digital communication link. Hybrid expansion unit communicates N-bit words of digitized spectrum with master host unit across digital communication link. Hybrid expansion unit converts between N-bit words of digitized spectrum and analog spectrum. Hybrid expansion unit communicates analog spectrum across analog communication link to analog remote antenna unit. Analog remote antenna unit communicates wireless signals using first antenna. Communication system further includes a switch in a data path between service provider interface and antenna. The switch selects between transmit path and receive path in response to switching control signal.