RoF-Based Indoor 5G DAS for Millimeter Wave Shadowing
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Solution Overview
Problem
The increasing demand for 5G indoor distributed antenna systems requires a cost-effective method to provide quality of service (QoS)-guaranteed mobile communication services with high bandwidth and low latency, while avoiding wireless shadowing in indoor environments, particularly for millimeter wave-based systems which face challenges with outdoor-to-indoor penetration loss and bandwidth efficiency.
Innovation Solution
A radio over fiber (RoF)-based 5G indoor distributed antenna system (DAS) network is implemented, utilizing a base station, main hub unit, remote antenna unit, and distribution points with electrical and optical interfaces to transmit and receive signals, enabling point-to-point and point-to-multipoint configurations, and supporting 5G signals, frequency synchronization, and system control signals, thereby ensuring uninterrupted and efficient network coverage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If millimeter wave-based outdoor-to-indoor communication is used, then high bandwidth is achieved, but penetration loss increases and service reliability deteriorates
Solution Approach 1:
The patent introduces an optical fiber as an intermediary transmission medium between the base station and indoor distributed antenna units. The RoF architecture converts RF signals to optical signals for transmission through fiber optic cables, which then convert back to RF at the destination. This intermediary optical transmission path bypasses the penetration loss issues of direct millimeter wave propagation, enabling high-bandwidth 5G services to be reliably delivered indoors.
2Adaptability or versatility
If digital conversion is performed at each antenna unit, then signal processing flexibility is improved, but system complexity and cost increase
Solution Approach 1:
The patent extracts the digital conversion functions (ADC and DAC) from the distributed antenna units and consolidates them at the base station. Only simple RF-to-optical and optical-to-RF conversion modules remain at the distributed units, while complex digital signal processing is centralized. This extraction reduces device complexity at remote locations while maintaining signal processing flexibility through centralized control.
Solution Approach 2:
The patent uses optical copying of RF signals to distribute identical signal copies to multiple distributed antenna units simultaneously. Instead of performing independent digital conversions at each unit, the same RF signal is optically replicated and distributed, reducing overall system complexity while maintaining the ability to process signals flexibly through centralized digital processing at the base station.
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
The RoF-based DAS effectively provides QoS-guaranteed 5G mobile communication services with high bandwidth and low latency, eliminating wireless shadowing and optimizing bandwidth utilization without the need for redundant digital conversions, thus enhancing indoor network performance.
Implementation Method 1
an optical interface that transmits an analog IF-based data signal and a digital-based auxiliary signal
Data Source
AI summary
Provided is a radio over fiber (RoF)-based distributed antenna system (DAS) structure that cost-effectively provides a fifth generation (5G) mobile communication service guaranteeing a quality of service (QoS) with high bandwidth and low latency characteristics without radio shadowing in an indoor environment.