Real-Time Experiments with a Scalable MIMO-OFDM Air · PDF file1 © Nokia Siemens Networks Dr. Thomas Haustein / December 2007 Real-Time Experiments with a Scalable MIMO-OFDM Air-Interface

1 © Nokia Siemens Networks Dr. Thomas Haustein / December 2007

Real-Time Experiments with a Scalable MIMO-OFDM Air-Interface –

Outdoor Measurements in Typical Urban Environments

PANU & MITSE workshop17th December 2007

Dr. Thomas Haustein, Dr. Egon SchulzCOO RTP PT RST CT Munich


Scalable MIMO OFDMA demonstrator

3 GSM World Congress

Barcelona, 2007

ITU Telecom World

Hong Kong, 2006

Experimental UE

Carrier Frequency: 2.6 GHz (UMTS Extension band)Duplex: FDDScalable Bandwidth: 20 MHz, 10 MHz, 5 MHzData rate @ 20 MHz: 200Mbps (DL), >50 Mbps (UL) Transmission Time Interval (TTI): 0.5 msModulation schemes:

Downlink OFDMA (64QAM, 16QAM, QPSK)Uplink SC-FDMA (16QAM, QPSK, BPSK)

Antenna techniques:Downlink 2x2 MIMOUplink 2x2 MIMO, SDMA, Rx-Diversity

CQI based Link Adaptation (DL) Time, Frequency, Space

Portable 19 inch / 3HULocal Management Terminal

LSUEuropean Road Show Outdoor MeasurementsBerlin, October 2007


Base Station

Antennas developed with Kathrein: 1900-2700 MHz

Formfactors

UE 19’’ rack

LMT


Baseband and RF

A Flexible Hardware Concept


LTE nodeB


LTE nodeB

RF-units

Duamco

LSU – LTE Server Unit


LTE User Equipment


LTE User Equipment

Touchpanel for UE control

Gigabit Ethernet hub for clients

USB for LMT & Firmware upload


LMT – the Local Maintenance Terminal Online Features & Measurement modes

Received power per antenna pair

Impuls responses in f-domainper antenna pair

Reconstructed QAM symbols from Tx 1 & Tx 2

Bit-loading map per Tx antenna

Uncoded & coded BER DL CFO

Rate per UE and aggregated rate at BS


MIMO-OFDM Experiments

Measurements in Outdoor ScenariosFirst Steps towards Cellular LTE


Outdoor Measurements Single User & Multi-User Scenarios

•Single User transmission DL: – DL 2x2 MIMO, fast link adaptation in DL, 20 MHz– UL 1x2 MRC, DFT pre-coding, QPSK, 5MHz– UE works in closed loop mode– Lists of CQI values, Rates, BERs and channel measurements are

recorded

• MU Scheduling in DL:– 1 BS, 2 UEs using 1 Tx each in UL, TDMA & QPSK for control

channel– 2 UEs calculate individual link adaptation in DL (prefered MCS

choice, MIMO mode, CQI)– Scheduler at BS decides frequency adaptive resource alloc. (e.g.

max rate or Prop Fair)


Outdoor Measurements Measurement Equipment


Adaptive Multi-Antenna Gains in Outdoor Scenarios

Measurements near NSN facilities in Munich

A

B

C


Single and dual stream selection and achieved sum throughput in scenario

Distribution of single stream and dual stream selection

Allocated Modulation on RBs and Tx antennas

Ach

ieve

d R

ate

[Mbi

t/s]

A

B

C

SIMO Tx1SIMO Tx2MIMO

Ach

ieve

d R

ate

[Mbi

t/s]

A

B

C


Adaptive Multi-Antenna Gains in Outdoor ScenariosMeasured throughput distribution in scenario


Adaptive Multi-Antenna Gains in Outdoor ScenariosThroughput Distribution and MIMO Selection Probability

-- dual stream / MIMO

-- single stream

Balance PointThroughput Balance Point:Dual-Stream allocated RBsachieve same throughput as single stream alloceted RBs, but dual stream mode has higher spectral efficiency.

Selection Balance Point:Number of RBs in Dual-Stream is equal to those in single stream mode. Multiuser diversity will shift thisposition towards lower SNR.


Multi-user Transmission Scenarios

BS

Downlink •UEs measure the downlink channel quality based on the pilots transmitted from the base station

•Each UE is calculating MCS and MIMO modes for each RB considering the applied MIMO detector


Multi-user Transmission Scenarios

BS

Downlink

•CQI values are fed back to the base station via a dedicated control channel.

•The BS scheduler is performing the frequency adaptive resource allocation and transmitting the final resource map to all UEs.

data

feedback channel

data

MIMOradio channel

adaptive Tx

Rx withrealtimesignal

processing

frequency


Multi-user Scheduling with Link AdaptationProposed MCS levels from UE0 Scheduler Input

----- single stream----- dual stream / MIMO


Multi-user Scheduling with Link Adaptation Proposed MCS levels from UE1 Scheduler Input

----- single stream----- dual stream / MIMO


Multi-User Scheduling – Scheduler Output with Proportional Fair Scheduling including SDMA

data from measurement 17


Multi User Scheduling – Results BERs

UE 1

UE 0


LTE-Outdoor ExperimentsMulti-User Scheduling

2 UEs moved at the NSN facilities in MunichMultipath environment, no LOS to BS


LTE-Outdoor ExperimentsResults in Multi-User Scheduling


Outdoor Measurements in Berlin


Multi-Antenna Gains in Outdoor Scenarios– Campus Scenario: 2,6 GHz, BW: 20 MHz, BS @ 60 m height

BS BS

v~3-5 km/h MIMO/SIMOSISO


Measured Throughput with different Multi-Antenna Configurations

•Configurations: -Campus scenario -2 UEs co-located in one car -x-pol. Rx antennas at UEs-pedestrian speed -MIMO: 2Tx, 2Rx -frequency adaptive LA


Measured Throughput of copplarized vs. cross-polarized Tx-Antennas at nodeB

•Configurations: -Campus scenario -2 UEs co-located in one car -x-pol. Rx antennas at UEs-pedestrian speed -MIMO: 2Tx, 2Rx -frequency adaptive LA


Measurement of coplanar vs. cross-polarized Antennas Polarization & Multi-user Gain


BS Site: HHI Building

Early LTE MeasurementsScaleNet Demonstrator

Berlin, Nov 2007

COO RTP PT RST

MIMO/SIMO

DLink

900 m

600 m

300 m

Ernst Reuter Platz

Urban, 5 – 40 km/h20 MHz, 2.6 GHz, Tx power: 34 dBm11 dBi antenna gainAdaptive MIMO


Single Sector Coverage MIMO supporting areas in the sector

-- Single Stream-- Dual Stream / MIMO

300 m

600 m

900 m

Urban, 5 – 40 km/h20 MHz, 2.6 GHz, Tx power: 34 dBm11 dBi antenna gainAdaptive MIMO

Early LTE MeasurementsScaleNet Demonstrator

Berlin, Nov 2007

COO RTP PT RST

BS Site: HHI Building

Ernst Reuter Platz


Thank you for your attention !

Documents

Real-Time Experiments with a Scalable MIMO-OFDM Air · PDF file1 © Nokia Siemens Networks Dr. Thomas Haustein / December 2007 Real-Time Experiments with a Scalable MIMO-OFDM Air-Interface