commscope: antennas solutions for capacity improvement - june 2014
DESCRIPTION
From LTE World Summit 2014TRANSCRIPT
Antennas Solutions for Capacity Improvement
Kevin Linehan June, 2014
Copyright © 2014 CommScope, Inc. – All rights reserved.
2PRIVATE AND CONFIDENTIAL. Copyright © 2014 CommScope, Inc. – All rights reserved.
Topics
• Introduction
• BSA evolution and trends
• Capacity Solutions –BSAs
• BSA standards
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SECTORIZEDOMNI DIRECTIONAL
• Increases capacity• Beamwidths 65, 90,105• Coverage shaping
• Mechanical tilt• El beamwidth
� Radiates equally� x2 for RX spatial diversity
1983 1989
• Single BSA for both RX diversity arrays
• Dual, slant 45 polarization replaces vertical pol
1997
DUALPOL
BSA Evolution and Trends
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ELECTRICAL TILT & RET MULTI- & BROAD- BAND
• Covers wider bandwidth• More arrays in a radome• Minimizes visual impact
• Coverage superior to mechanical tilt
• Remote Electrical Tilt avoids tower climbs
• RX diversity
2001 2003
BSA Evolution and Trends
LTE & MIMO
• 2X2 MIMO on the DL• 4 RX diversity – HB diversity• 4X2; 4X4 MIMO upgradable
Now
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TD-LTE BEAMFORMERS
BSA Evolution and Trends
One Twin Beam BSAOne 65° BSA
1 sector 2 sectors
MULTI-BEAM
• Two beams from one BSA• Each beam dualpol• Planar array with Bulter matrix• Beams have individual downtilt
• Planar Array• WiMax ► TD-SCDMA ► TD-LTE• 4 port v-pol ► 8 port dual-pol ► RET
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Macro-cell integration: RF into the antenna
HetNet
BSA Evolution and Trends
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What Are Today’s
Antenna Solutions to
Capacity Challenges?
What Are Today’s
Antenna Solutions to
Capacity Challenges?
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Capacity Resources
increased spectral efficiencyadditional spectrum
densification
Moray Rumney. Smart Cells and Wireless Capacity Growth. PowerPoint Presentation for Agilent Technologies in LTE World Summit, Posted Online May 26, 2010
Historically
dominated by an
increase in
cells/sectors .
20 25
2,000
SpectralEfficiency
Spectrum No. ofCells/Sectors
Growth Factor
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Capacity is Determined by SINR
Maximum throughput requires:
• Interference Reduction and Optimization
• Noise Suppression in the RF path
• Sector Sculpting
• Load Balancing
Motorola Whitepaper: Realistic LTE Performance –
From Peak Rate to Subscriber Experience, 2009
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The design goal of a shaped beam is to:• Direct maximum energy into the illuminated• Minimize interference into all other sectors
Antenna Pattern Quality is Key to Good SINR
* Typical horizontal BW antenna patterns from initial
deployments of GSM/UMTS
90º Antenna
65º Antenna
High Performance 65º Antenna
• Theoretical site geometry• Real antenna pattern
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Sector Sculpting - Horizontal Pattern
Standard 90 ° BSAHigh Performance –5dB
80°
–12dB
–25dB
–5dB
90°
–10dB
–18dB
–40dB –25dB
Roll offat –/+ 60°
–10 dBpoints
Front-to-Side Ratio
Next SectorAnt/AntIsolation
Front-to-Back
Ratio
Key characteristics
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Sector Sculpting - Elevation Pattern
Key characteristics
SidelobeSuppression
Main LobeMain Lobe
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Antenna Height Tilt Outer Measure at -3dB
20 ft. 20 deg. 103 ft.
20 ft. 16 deg. 175 ft.
40 ft. 16 deg. 350 ft.
Beam Tilt & Side Lobe Suppression of Metro Cells
Desired Metro Cell Vertical Beam Pattern
12- 20º
Horizon (0º)
Control over upper side lobes keeps RF interference out of nearby buildings and other cells
Point of greatest interference(lowest SINR) should be well-defined
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Three Simulations of Metrocell HetNets
• Monte Carlo RF Planning Tool– Cluster of cell sites simulated – Dense urban– UE is located randomly 1000’s of times
• Poisson Point Process Simulation– UT Austin- cells are random PPP– UE is located at the origin point– Network is created 1000’s of times
• Monte Carlo - Matlab Simulation– Bias and Load balancing considered– Typical load on network at 50%
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Summary
• Impact of vertical beamwidth– Without down tilt, average spectral efficiency decreases as the vertical
beamwidth of small cell antenna decreases (beam reaches deeper into network, lowering SINR)
• Improved University of Texas model using Poisson distribution with 3D calculations and Atoll both confirm improvements of antenna tilt
• Impact of antenna down tilt– Average spectral efficiency is improved approx. 40% over standard omni
• Recent studies indicate with load balancing there is an optimum tilt balancing small cell off load and HetNet intereference
Control over Vertical Beamwidth and Down Tilt Matter s!Control over Vertical Beamwidth and Down Tilt Matter s!
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MetroCell Quasi-Omni BSA
• Three 65°BSA’s combined• Dual Band, DualPol• Electrical Tilt & RET• Uppersidelobe suppression• Sectorizable
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Multi-Beam BSAs to Increase Capacity
• More capacity due to increased sectorization
• Ideal solution for high traffic sectors and events
• Extends value of existing cells
• Fast and easy deployment
2 Beams(2 x 38°)
5 Beams(5 x 12°)
9 Beams(9 x 6°)
18 Beams(2 x 9 x 6°)
3 Beams(3 x 24°)
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View from behind antenna looking outward:
9.4°
8°
~90°
2x9-Beam Antenna
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BSA Standardization Benefits
� Reduces ambiguity � Reduces miscommunication � Facilitates cost / benefit decisions� Drives higher quality and performance
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Example Specification: Front to Back Ratio
Front to Back (F/B) is a single sided specification
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Front-to-Back Ratio
• There are many ways to specify Front-to-Back Ratio, which varies with frequency and tilt• Typical F/B Co-pol only at 180 degrees: This is the default industry standard• BASTA: Total Power (Co + Cross-pol) over 180±30 degrees across tilts and frequencies
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Gain Specification
• There are many ways to specify gain, which varies with frequency and tilt• Maximum (or near maximum) gain: This is the default industry standard• Minimum gain: desired by some customers, no vendor uses• BASTA: average value across tilts and frequencies
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Thank-you!
Questions?
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