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LOS Throughput Measurements in Real-Time with a 128-Antenna Massive MIMO TestbedPaul HarrisSiming Zhang, Mark Beach, Evangelos Mellios, Andrew Nix, Simon Armour, Angela Doufexi, Karl Nieman, Nikhil KundargiCommunication Systems and Networks Group University of Bristol, Bristol, UK http://www.bristol.ac.uk/engineering/research/csn/

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.1

SummarySystem Overview

Measurement Setup

Experimental Results

Conclusions

Ongoing Work2

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.The Massive MIMO Concept3

Ultimate Spatial ResolutionIncreased spectral efficiency and network capacityAccurate spatial multiplexing

Time

Space

UplinkDownlinkUplinkUplinkUplinkDownlinkDownlinkDownlink

Cellular View

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.NI Based BIO Massive MIMO test-bed4128 Programmable Radio Heads (4 racks of 32 radios)

TD-LTE like PHY (20 MHz BW)

1.2 6.0GHz Carrier (3.51GHz used)

Centralised MMSE, ZF and MRC/MRT MIMO Processing

Supports up to 12 User Clients (Full FPGA Processing)

24 user clients (decimated processing)

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.Functional Overview5

Distributed FPGA Processing with PCIe links

Compact Computer

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.Linear Decoding/Precoding

6

MGS Full QR Decomposition

Partial parallel systolic array

One detection matrix per 12 subcarrier resource block

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.MIMO ProcessorWide Data Path 128 x 12 Linear DetectorComputes 128 x 12 by 128 x 1 matrix vector multiply in 160 ns24 Million times per second7

12 x 128128 x 112 x 1 32 x 1 (4) 12 x 32 (4)

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.Frame Schedule

8

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.Initial Indoor Deployment9

5.4m Linear Array with half-wavelength spacing

Client Separation 2.5 6

Equal and fixed UE Tx Gains

LOS Conditions

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.Initial Indoor Deployment10

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.CDF Plots of SVS

11Scenario 1-3 in ascending order of LOS distance. 200ms capture interval for 3 minutes. Averaged across frequency.

Exploitation of azimuth spreadClosest scenario is the worst for 32 elements

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

12Scenario 2 (12.5m Straight Line). 200ms capture interval for 3 minutes. Averaged across frequency and time.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.Real-Time Channel Information13

Eigen StructureIndividual Spatial Stream Rx MagnitudePower Delay profilesFrequency Domain profiles

Fading over the array caused by stairwell

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.12 Streams of 256-QAM

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IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.2nd Phase Deployment (11th May 2016)15

24.8m

3.51 GHz Patch Array24 UEs2.5 spacingPresented at SiPS 2016, Dallas.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.22 User Gram Matrix

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IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.22 Streams of 256-QAMWith the same frame structure as before this equates to 145.6 bits/s/Hz (uncoded sum rate of 2.915 Gbps)

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User InactiveUser Inactive

131 bits/s/Hz144 bits/s/Hz145.7 bits/s/Hz

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.ConclusionsAverage ratio of composite channel gain to inter-user correlation observed to be 10 dB or more for a ratio of up to 6:1 basestation antennas to users

Azimuth dominated array configurations could improve close range LOS performance

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IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.Ongoing Work19

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.Acknowledgements and Thanks toPost Graduate Students: Wael Boukley Hasan, Siming Zhang, Henry Brice & Benny Chitambira

Academic Colleagues & post graduates at Lund University: Steffen Malkowsky, Joao Vieira, Liang Liu, Ove Edfurs & Fredrik Tufvesson

Academic Colleagues at Bristol: Mark Beach, Andrew Nix, Evangelos Mellios, Angela Doufexi and Simon Armour

NI Staff: Karl Nieman, Nikhil Kundargi, Ian Wong, Leif Johansson & James Kimery

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IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.Thank YouAny questions?

Communication Systems and Networks Group University of Bristol, Bristol, UK http://www.bristol.ac.uk/engineering/research/csn/

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.

IEEE Globecom, WCS.10: Channel Measurements and Modeling5th December 2016, Washington D.C.