Distributed Repeater Using Analog IF Signals
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Solution Overview
Problem
The high cost and complexity of existing digital-type distributed repeaters for in-building wireless mobile communication systems, due to the need for multiple modulation/demodulation circuits in remote service units, increase the price and complexity of installation.
Innovation Solution
The system converts mobile communication signals into analog intermediate frequency (IF) signals, allowing transmission and reception through Ethernet cables with frequency shifting and division multiplexing, enabling the use of cheaper components and simplifying the configuration of remote service units, with power transmission over Ethernet and coaxial cables, and managing multiple units through standard protocols.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If digital-type distributed repeaters use modulation/demodulation circuits in remote service units, then signal transmission quality is improved, but system cost and complexity increase
Solution Approach 1:
The patent extracts the modulation/demodulation functionality from remote service units and concentrates it in the headend unit. Remote service units are simplified to only perform signal amplification and Ethernet transmission, while the headend unit handles all digital signal processing including modulation and demodulation. This extraction resolves the contradiction by maintaining signal quality through centralized processing while dramatically reducing complexity at distributed locations.
Solution Approach 2:
The patent merges multiple functions (modulation, demodulation, signal processing, and Ethernet interface) into a single headend unit. By combining these functions centrally rather than distributing them across multiple remote units, the system achieves reliable signal transmission while reducing overall device complexity and cost.
2Adaptability or versatility
If multiple remote service units include modulation/demodulation circuits, then signal processing capability is improved, but manufacturing cost increases
Solution Approach 1:
The patent segments the system into two functional parts: a sophisticated headend unit with all signal processing capabilities, and simple remote service units with only amplification and transmission functions. This segmentation allows one unit to have high adaptability while the other remains inexpensive to manufacture.
Solution Approach 2:
The remote service units are designed as inexpensive, simple devices without expensive modulation/demodulation circuits. By making these distributed units cheap and simple while concentrating complexity in the headend, the system achieves versatile signal processing capability without high manufacturing costs for each remote unit.
3Ease of manufacture
If analog IF signals are transmitted through Ethernet cables, then system cost is reduced, but signal transmission distance and quality may be affected
Solution Approach 1:
The patent uses Ethernet cables as an intermediary medium to transmit analog IF signals from the headend to remote service units. By selecting appropriate IF frequencies and utilizing the existing Ethernet infrastructure, the system achieves cost reduction while maintaining acceptable transmission quality for the required distances within buildings.
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 cost and complexity of the distributed repeater system by using cheaper components and simplifying the configuration, while maintaining effective signal transmission and management, thereby lowering the overall system price and facilitating easier installation.
Implementation Method 1
mobile communication signals of mobile communication service carriers in communication between devices of an in-building distributed repeater system are converted into analog intermediate frequency (IF) signals obtained through frequency shifting to lower bands
Implementation Method 2
a headend unit and an active antenna unit may transmit and receive one analog IF signal generated by frequency-division-multiplexing service-band-wise analog IF signals
Implementation Method 3
a headend unit and a remote service unit may transmit and receive a plurality of analog IF signals by service band through a plurality of wire pairs of an Ethernet cable
Implementation Method 4
the remote service unit may receive power from the headend unit through an Ethernet cable without a separate power cable
Implementation Method 5
the active antenna unit may receive power from the headend unit through a communication cable without a separate power cable
Data Source
AI summary
Disclosed is an in-building distributed repeater technique for distributing a wireless mobile communication signal into a building. Mobile communication signals of service carriers in communication between devices of an in-building distributed repeater system may be converted into intermediate frequency (IF) signals with adjacent frequency bands and may be transmitted or received as analog signals with compressed bandwidths through frequency division multiplexing. The service band gap spacing of Tx downstream analog IF signals transmitted by a headend unit to a remote service unit is wider than that of Rx downstream analog IF signals received from an active antenna unit.