Base Station Antenna Evolution and · PDF fileBase Station Antenna Evolution and Revolution...
Transcript of Base Station Antenna Evolution and · PDF fileBase Station Antenna Evolution and Revolution...
September 18-19, 2012
Mobile Antenna Systems 2012 Denver, CO Base Station Antenna Evolution and Revolution David Barker, CTO Keith Radousky, CTO – Americas
Copyright © 2012 Quintel. All rights reserved. Quintel Confidential.
Dave Barker authored the submitted paper and this material. He was scheduled to present it today but
unfortunately he is unable to attend, so I will be presenting on his behalf.
Copyright © 2012 Quintel. All rights reserved. Quintel Confidential.
The Capacity Crunch
• The Capacity crunch • We are all aware of it • By 2025 there may be 50x, 500x increase?
• How is it solved?
– More Spectrum (~3x increase by 2025) – More Spectral Efficient access tech (~3x increase by
2025) – More Spectral re-use/denser topologies (~?x increase) – Pricing mechanisms
• Small Cells are the acknowledged answer in the
form of Femtos, Picos, etc and part of a HetNet.
• But the Macro Layer won’t be replaced by Femto Layer, so how can the Macro layer evolve and be prepared for the Capacity crunch?
Source: Verizon
How do we close the gap?
Shannon’s Limit has essentially been
reached; this is all Spatial
Multiplexing/MIMO
Copyright © 2012 Quintel. All rights reserved. Quintel Confidential.
Space Efficiency Techniques
Multi-array
Multi-Port
Combiners
How the Base Station Antenna has evolved Maxwell’s Laws not Moore’s Law
Source: 3G Americas; 3G & 4G Antenna Deployment
Point of Flux: Reconfigurable?
Active? Adaptive?
More Bands?
2012?
Spectral Efficiency Techniques
Spectral and Space
Efficiency Mutually Exclusive
Copyright © 2012 Quintel. All rights reserved. Quintel Confidential.
Spectrum Evolution
400
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1990 GSM/GPRS/EDGE
1998
2004
UMTS/HSPA/HSPA+
2020 White Space/Interleaved Spectrum 8x8 MIMO, CoMP, ICIC.
Elevation Beamforming Azimuth Beamforming
2012
LTE FDD Rel 8/9/10/11
2x2 MIMO and Tx Div.
• FCC, UK, India promise another 500MHz by 2020; and with “hands-off” approaches, incentive auctions and trading of spectrum.
• LTE-A is aligned with this multi-band concept to achieve 1Gbps and beyond. • Results in more Spectrum Neighbours = more Inter-System interference scenarios
(GPS, DTV, Public Safety, PMR/SMR) • Results in more Intra-System PIM Issues, especially with higher power Tx • Logic could be to eventually migrate to cognitive radio systems, as per White
Space model?
Receive Div. Only
2016 TD-LTE Rel 8/9/10/11
4x4 MIMO, CoMP. Azimuth Beamforming
DD2
Copyright © 2012 Quintel. All rights reserved. Quintel Confidential.
More Spectrum Example of Intra System Interference
“Back to the Future” Solution
Problem
GSM/UMTS 850AB
LTE 700
Quintel MultiServ Antenna
(Tx)
Quintel MultiServ Antenna (Rx)
T R T R
700/850 Combiners
700/850 Combiners
700/850 Combiners
700/850 Combiners
700/850 Combiners
700/850 Combiners
700/850 Combiners
700/850 Combiners
Rx: 700BC
Tx: 700DEBC
Either Un-duplex or break out at native
Tx, Rx ports
All Tx Sub-Bands are Transmitted (30MHz)
A Spectral Efficiency Technique
Copyright © 2012 Quintel. All rights reserved. Quintel Confidential.
MIMO Spectral Efficiency Evolution in LTE
ULA
numberofsources
averagerelativegain
CS/CB SU-MIMO 2x2 vs. SU-MIMO 2x2 9 cells 2 Cell avg 4.03%Cell-edge 4.42%
CS/CB SU-MIMO 4x2 vs. SU-MIMO 4x2 9 cells 4 Cell avg 5.32%Cell-edge 20.64%
CS/CB MU-MIMO 2x2 vs. MU-MIMO 2x2 9 cells 2 Cell avg 4.07%Cell-edge 8.93%
> 9 cells 1 Cell avg 5.66%Cell-edge 25.08%
CS/CB MU-MIMO 4x2 vs. MU-MIMO 4x2 9 cells 6 Cell avg 4.12%Cell-edge 12.22%
> 9 cells 2 Cell avg 2.29%Cell-edge 21.76%
JT SU-MIMO 2x2 vs. SU-MIMO 2x2 9 cells 3 Cell avg 1.55%Cell-edge 19.84%
JT SU-MIMO 4x2 vs. SU-MIMO 4x2 9 cells 3 Cell avg 1.12%Cell-edge 13.49%
JT MU-MIMO 2x2 vs. MU-MIMO 2x2 9 cells 3 Cell avg 13.53%Cell-edge 40.50%
JT MU-MIMO 4x2 vs. MU-MIMO 4x2 9 cells 5 Cell avg 11.40%Cell-edge 28.87%
> 9 cells 1 Cell avg -9.15%
Cell-edge 34.34%
cross-polarized antenna
numberofsources
averagerelativegain
CS/CB SU-MIMO 2x2 vs. SU-MIMO 2x2 1 Cell avg 1.46%Cell-edge 2.86%
CS/CB SU-MIMO 4x2 vs. SU-MIMO 4x2 5 Cell avg 5.65%Cell-edge 16.68%
CS/CB MU-MIMO 2x2 vs. MU-MIMO 2x2 9 cells 3 Cell avg 3.71%Cell-edge 5.17%
> 9 cells 2 Cell avg 0.86%Cell-edge 15.21%
CS/CB MU-MIMO 4x2 vs. MU-MIMO 4x2 9 cells 7 Cell avg 3.63%Cell-edge 11.66%
> 9 cells 2 Cell avg 1.09%Cell-edge 17.32%
JT SU-MIMO 2x2 vs. SU-MIMO 2x2 9 cells 2 Cell avg 2.19%Cell-edge 14.80%
JT SU-MIMO 4x2 vs. SU-MIMO 4x2 9 cells 5 Cell avg 3.57%
Cell-edge 21.78%JT MU-MIMO 2x2 vs. MU-MIMO 2x2 9 cells 7 Cell avg 4.07%
Cell-edge 40.72%> 9 cells 1 Cell avg 3.57%
Cell-edge 18.57%JT MU-MIMO 4x2 vs. MU-MIMO 4x2 9 cells 7 Cell avg 8.70%
Cell-edge 31.35%> 9 cells 1 Cell avg 6.86%
JT: Joint Transmission (Multi-Cell Tx) CS/CB: Co-ordinated Scheduling & Beamforming
2x2 Single User MIMO
R8
2012
3GPP Study item in release 11 LTE 3GPP TR 36.819 V11.0.0 (2011-09) captures these simulation results. CoMP/ICIC techniques in particular improve cell edge performances. Slow but steady evolution in Spectral Efficiencies, at the expense of complexity.
2x2 Multi User MIMO
R9 Dual Layer Beamforming (R9) Azimuth Plane Coherent Beamforming
Emphasis on UE only having 2x
Antennas
4x2 Single User/Multi Cell MIMO (CoMP)
R10
2015 Tx1
Higher-order Azimuth Plane Coherent Beamforming
Tx2
4x2 Multi User/Multi Cell MIMO (CoMP)
R11
2018 Tx1
Tx2
1.4
1.8 2.3
2.5 2.7 3.5
3.0 3.4 4.0
Spectral Efficiency (bps/Hz)
Copyright © 2012 Quintel. All rights reserved. Quintel Confidential.
MIMO Spectral Efficiency Evolution in LTE Dual Layer Beamforming in LTE Release 9
• With 3GPP Release 9 (TD-LTE) and Release 10 (FDD), a feature called “Dual Layer Beamforming” allows the LTE Downlink shared traffic channel to use 2x2 Spatial Multiplexing MIMO plus Adaptive Beamforming.
• With 4xPA’s (i.e. a 4T4R Base Station) you can transmit a signal on two feeders; each signal carrying the same information but having different phase weights.
• Example shown left, where different LTE Physical resource Blocks (i.e. different groups of LTE OFDM Sub-Tones) are delivered with different Azimuthally Beamformed patterns.
• Each user receives their respective signals via individual optimal Beamformed patterns.
• Beamforming in this way improves overall C/I which in turns ensures that Spatial Multiplexing occurs more often.
+45 -45
4T4R Base Station
+45 -45
Base Pattern of each array
Azimuthal Beamformed Patterns created for different users
(using different Physical Resource Blocks in Time & Frequency)
Copyright © 2012 Quintel. All rights reserved. Quintel Confidential.
MIMO Engineering & Innovation Back to the Future: Space Diversity for Spectral Efficiency?
Quintel Dualband 8 Port Antennas (698-894MHz/1710-2170MHz)
6x Independent Tilts
LTE-AWS
UMTS 850
GSM 1900
GSM 850
LTE 700
UMTS 1900
700/850/1900 Combiners
700/850/1900 Combiners
700/850/1900 Combiners
700/850/1900 Combiners
700/850/1900 Combiners
700/850/1900 Combiners
700/850/1900 Combiners
700/850/1900 Combiners
Hybrid Space+Polz Diversity For all services
2x2 MIMO LTE(AWS) Remote Head Solution shown
• For 2x Antennas per sector. • Quintel solution allows initial 2x2 MIMO with
either: – Conventional X-Polar only, or – Spatially Separated orthogonal Polarisations
• Upgrade to 4x4 MIMO on 700 and AWS bands • Patented technique and application.
A Spectral Efficiency Technique
2x2 MIMO LTE700
“Back to the Future” Solution
Quintel MultiServ Antenna
Quintel MultiServ Antenna
Modelling and capacity of polarized MIMO channels Mikael Coldrey Ericsson Research, Ericsson AB, SWEDEN 1dB Spectral Efficiency Gains
1998 IEEE Paper 1dB Diversity Gains
Copyright © 2012 Quintel. All rights reserved. Quintel Confidential.
Antenna Innovation What could be achieved?
• Multi dimensional applications covering • Optimisation of different access technologies in same freq band • Optimising individual RF channels within same standard • Enhancing cell throughput on network or cluster basis.
Spectral Efficiency
Techniques
Elevation Beamforming
Copyright © 2012 Quintel. All rights reserved. Quintel Confidential.
Antenna Hardware Evolution?
• There are Active Antennas which are purely active, offering 1x box at the top of the mast.
• Then, there’s a roadmap for Active Antennas which also will promise adaption of the (vertical) beam pattern on a per Physical Resource Block (PRB) or user resolution basis.
• The latter being a focus of a lot of OEM vendors right now; fits with slim line antennas for Western markets.
• Quintel are offering a complimentary solution delivering smart (adaptive) coherent Beamforming in radio channels where full complex vector control of each antenna element isn’t necessary.
Bas
eban
d/D
AC
/RF
Sta
ges
Opt
ical
Fib
re
Active Adaptive Antenna
Baseband Server
Innovation: Quintel
Multi-Band Capable Offers Active/Smart
antenna type features Completely Passive
Opt
ical
Fib
re
Baseband Server
Qui
ntel
Cor
pora
te F
eed
BB-RF
Dual-PA IRU
Full Complex vector control at each element
(Fully Active Adaptive Array)
Copyright © 2012 Quintel. All rights reserved. Quintel Confidential.
Qui
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Net
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Cor
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N
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Qui
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5o )
Pha
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Shi
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T R T T R T
Dynamic (adaptive) tilting (per user) for LTE Uplink Independent Static Tilt for LTE Downlink
+45 -45
LTE eNB (2T/4R Configuration)
T R T R
RxD3 RxD4
R
A Solution for Spectral Efficiency MultiWav - Adaptive Elevation Beamforming (Uplink only)
Tx/Rx2 Tx/Rx1
• Connecting a 2T4R Base Station as shown with 4-way Maximal Ratio Combiner (MRC), rather than usual 2-way MRC.
• MRC algorithm simply applies weights and phase delays to the 4x Rx inputs to maximize C/I, and will do this on a per channel (per user) basis at baseband.
• Applying phase delays to within each of the Rx differential pairs is simply creating a coherent beam (tilt) toward/from each user/terminal, and then applying phase/weights between +45 and -45 is then standard 2-way Rx diversity.
LTE Downlink LTE Uplink (Adaptive)
T R
4-Way MRC
T R
Σ
R
Spectral Efficiency Techniques
Copyright © 2012 Quintel. All rights reserved. Quintel Confidential.
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LTE (R9+) 4T4R
+45A +45B -45A -45B
Beamforming in Elevation across each A&B ports
Spatial Multiplexing up to Rank 2 across +45 and -45 BF pairs
Dynamic Beamform/Tilting for LTE
Interference
UE
A Solution for Spectral Efficiency MultiWav - Adaptive Elevation Beamforming (Up & Downlink)
Can be a 2T4R eNodeB (giving Uplink adaptive coherent Beamforming)
0
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0 100 200 300 400 500
LTE 2GHz/20MHz 2x2 Config Flat Earth 3x19 cell geometry
(25m Ht x 500m Cell Radii) Monte-Carlo Simulation
Mbps (y) vs. Dist in m (x) Blue – No Elevation BF
Red – With Elevation BF
Copyright © 2012 Quintel. All rights reserved. Quintel Confidential.
Uplink throughput for Azimuth (CLA-2X) and
Elevation (Quintel) plane adaptive Beamsteering
Quintel technology has been researching this area and has developed a novel antenna design which effectively introduces a new 4x port Base Station antenna option for consideration. It is logically the same as the CLA-2X antenna configuration but performs coherent Beamsteering on a per UE or UE group basis in the Elevation plane, rather than Azimuth plane, and is based on a completely passive traditional column array, rather than an Active phased Array solution.
Copyright © 2012 Quintel. All rights reserved. Quintel Confidential.
Qui
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Qui
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Pha
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Shi
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9 8 9 8 9 8 9 8
GSM900, UMTS900
LTE800
4xTx/Rx
+45 -45
Dynamic Beamform/Tilting for LTE800 RET for 900
2xTx/Rx
• One 4T4R plus one 2T2R base station example shown
• Quintel advantage is that a single column array lends itself to dual-array (dual-band) topology readily. A side-by-side column array (conventional Azimuthal Beamforming) may prove difficult to make dual-band.
• Quintel can also offer our conventional independent (static) tilt for legacy services as illustrated left, as per our MultiServ product approach.
• Potentially, beamforming in elevation could prove more effective than beamforming in Azimuth, due to the fact interference comes from one direction (the horizon) rather than multiple directions as in Azimuth.
Quintel Elevation Beamforming Antenna Legacy support plus Adaptive Elevation Beamforming
Space Efficiency Techniques
Spectral Efficiency Techniques
And
Copyright © 2012 Quintel. All rights reserved. Quintel Confidential.
Thank You!
When wireless is pushed to the limit the answer isn’t more of the same
The answer is more innovation