Das solution

giải pháp DAS mimo trong hệ thống viễn thông Giải pháp SC MIMO bao gồm hai thành phần chính: Head Unit (HU) và Service Unit (SU). Các thành phần cần thiết khác là Bộ lọc DC+IF và Bộ ghép DC Pass.

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vertraulich / confidential

Overview of DAS Solutions

15-Jul-2017

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▪ In-Building Design Trends

▪ Marketplace Solutions and Building Types▪ Approaches to In Building System Design

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In-Building Design Trends

▪ Network Operators Prefer Passive Solutions

▪ Radiating cable now widely used

▪ Fibre optic technology used only where necessary▪Solution for large buildings

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Passive and Active DAS

Passive Solutions

Active Solutions

MainHub

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Why Use Distributed Antenna?

▪ Applicable where narrow range of frequencies are required and future expansion into other bands is not anticipated

▪ Single or Dual band systems.

▪ To provide hot spot coverage of open areas.▪ Highly cost effective.

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Why Use Radiating Cable?

▪ Flexibility / Cost- Effective Upgrading ▪ Broadband capability

2700MHz

▪ Advantages of leaky cable

▪Less close / far signal difference.

▪ Disadvantages of leaky cable

▪Difficult to match with interior design.

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Radiating Cable vs Antenna

▪ Major issue is the topology of the required coverage area.

rectangular or circular disposition.

and narrow office spaces such as those wrapping around the core of a high rise building.

▪ A radiating cable solution is generally more costly (material wise) than an antenna solution.

▪ Flexibility / Cost

unlimited number of services ranging from 1MHz to 2500MHz.

later without further installation costs.

would require a new antenna system.

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Antennas vs Radiating Cable

Radiating CableCoverage

Signal Strength

Distance

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▪ High system reliability

Active System

▪ Active systems overcome insertion loss, restoring antenna EIRPs and uplink system noise figure

▪ Duplex cellphone systems require elaborate and relatively expensive linear BDAs

▪ Linearity is critical; multiple carriers escalate 3OIP and power rating of downlink PAs

▪ Multiple radio platforms necessitate band-dedicated BDAs

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Passive DAS for LTE-A?

Pros of Passive DAS

▪ An all-passive coaxial cable system is highly linear

▪ Capable of handling multiple downlink carriers with no measurable IM products

▪ High system reliability.

Cons of Passive DAS

▪ Feeder cable size is typically limited to 7/8” or 1-5/8”▪ Not suitable for buildings that require long feeder runs▪ At high frequencies, the system loss becomes very high

▪ Lower DL coverage, poorer uplink sensitivity and reduced SNIR

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Hybrid DAS

▪ Most cost effective solution

▪ Difficult to manage uplink active systemfrom interfering with passive DAS

Hybrid Solutions

Master Unit

Coaxial Cable toAntennas

Coaxial Cable

RemoteUnitRF Repeater

Radiating CablesRadiating Cables

Coaxial Cable to Antennas

Donor BTS

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Hybrid DAS Application Scenarios

1 Multi StorySkyscraper

Rad Cable

3 Campus Environment

Fiber OpticsRemote Unit

Fiber OpticsMaster Unit

2 ShoppingCenter

Attached High Rise BuildingFiber

Master UnitFiber Optics

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Optimum Amplifier Placement

▪ Best results when amplifier is placed near to antenna.

▪UL NF is minimized, i.e better sensitivity

▪ Trade-off between how close amplifier is placed to the antenna, and number of amplifiers needed.

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▪ Scenario 1: No Amplifier

BTS NF plus cable loss

▪ Scenario 2: Amplifier Near the Antenna

between BTS and amplifier.

System Noise Figure = 50 dB

System Noise Figure = 16.2 dB

RXNF = 10dB

Overall NF16.19dB

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▪ Scenario 3: Amplifier Far from Antenna

▪ Amplifier gain compensates for feeder loss and thereby increasing performance.

System Noise Figure = 50 dB

RXNF = 10dB

Stage 1 Stage 2 Stage 3 Stage 4

Overall Gain-5dBOverall NF50dB

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NFh

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Approaches to ImplementCoverage Solutions

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Coverage Solutions

RF Repeater, Pico Repeater + DAS

E.g., Small Restaurant and Building

RF Repeater, Booster + DAS

E.g., Supermarket, Residential Building

BTS + DAS

E.g., Office Building, Shopping Mall

BTS + Fiber Repeater / Booster + DAS

E.g., Airport, Megamall

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High Capacity + Small Coverage Applications

WCDMA BTSDCS BTSGSM_B BTS

GSM_A BTS

Basement Car ParkTPX

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High Capacity + Large Coverage Applications

▪ Fiber optic repeaters are often used for large scale in-buildings where high coverage and capacity are needed.

▪ Typical applications are in airports, underground metros, exhibition halls, campus buildings, etc.

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Donor Antenna

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Low Capacity + Large Coverage Applications

Optical Repeaters

ANTOptical Fiber

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Low Capacity + Small Coverage Applications

Small OfficeDonor

▪ Using Indoor Pico Repeater

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Summary

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▪ The new Rosenberger Smart DAS solution can provide a flexible solution for a high power hybrid DAS and low power active DAS.

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THANK YOU

www.rosenbergerap.com