5G India 2017 - Bharat Exhibitions 1...5G India 2017 Ramarao Anil Head – Product Support, Development & Applications Rohde & Schwarz India Pvt. Ltd. COMPANY RESTRICTED . ... Broadcast

Demystifying 5G, Massive MIMO and Challenges

5G India 2017

Ramarao Anil Head – Product Support, Development & Applications

Rohde & Schwarz India Pvt. Ltd.

COMPANY RESTRICTED

Agenda

ı 5G Vision

ı Why Virtualization & C-RAN ?

ı Why Massive MIMO ?

ı Challenges & OTA

ı Summary

COMPANY RESTRICTED

5G Vision: A Union of Spectral & Energy Efficiency

Radio: Spectral Efficiency Virtualization: Energy Efficiency

Automotive

Public Safety

E-Health

IoT

Smart City Ecosystem

Ultra-Dense Broadband

Broadcast Mobility

Advanced test equipment bridging between radio &

virtualization

Both capacity and power consumption are critical for 5G success

BS Locations

Expenses

Revenue

Traffic

Time

Growth

Mobile data explosion

Voice dominated

Why 5G? Capacity vs. Revenue Increased Capacity, Increased OPEX

Expenses

Revenue

Traffic

Time

Growth

Mobile data explosion

Voice dominated

Optimal Network

?

Drive profit by reducing expenses (energy efficiency)

BS Locations

Low data rates

on edges

Cell Edge

Uniform

Coverage

Why 5G? Power Consumption

2G GSM

830,000 Basestations

80 GWH (96 KWH per BTx)

3G TD-SCDMA

350,000 Basestations

13 GWH (37 KWH per BTx)

WiFi Data Offloading

4.2 Million Access Points

2 GWH Power consumption

4G TD-LTE

800,000 Basestations

16 GWH (20 KWH per BTx)

Cellular Network Energy Consumption (China) Radio Access Network Energy Consumption

CAPEX OPEX

Biggest CAPEX/OPEX Expense is Air

Conditioning

Example: China Mobile Network in

2013 consumed over 15 Billion KWH

31%

7% 41%

21%

O&M

Electricity

Site

rent

Tx

46% 51%

3%

Air

conditioners

Equipment

Source: IEEE Communications Magazine, Feb 2014

CMRI, “C-RAN: The Road Towards Green RAN,” Dec. 2013

Cellular Infrastructure Evolution to 5G Passive Antennas & Separate Radio Transceivers

Active Antenna System

Antenna + Integrated TRx

Massive MIMO: Requires new T&M paradigms

Traditional: 1G & 2G Distributed: 3G & 4G Centralized: 4.5G & 5G

0.45 to 1.9 GHz 0.7 to 3.6 GHz 3.4 to 6 GHz & 20 to 60 GHz

8 dual-polarized antennas 8+ dual-polarized passive antennas 128 to 512 active antennas

Peak data rate: 114 kbps Peak data rate: 150 Mbps Peak data rate: 10 Gbps

Energy Efficiency: C-RAN & Network Virtualization

Virtual Basestation Pool (Real-time Cloud BBU)

BS1: GSM Phy/Mac

BS2: LTE Phy/Mac

BS3: 5G Phy/Mac ...

RTOS RTOS RTOS ... Hypervisor

General Purpose Processor Platform

Distributed configurable wideband RRU

High bandwidth optical transport network

Centralized Control/Processing

Centralized processing resource pool that can support 10~1000 cells

Collaborative Radio

Multi-cell joint scheduling and processing

Real-Time Cloud

Target to open IT platform

Consolidate the processing resource into a cloud

Flexible multi-standard operation and migration

Clean System Target

Less power consuming

Lower OPEX

Fast system roll-out

-15% Capital Costs

-50% Operating Costs

-70% Power Consumption

Architecture Equipment Air Con Switching Battery Transmission Total

Traditional 0.65 kW 2.0 kW 0.2 kW 0.2 kW 0.2 kW 3.45 kW

Cloud Radio 0.55 kW 0.1 kW 0.2 kW 0.1 kW 0.2 kW 0.86 kW

CMRI, “C-RAN: The Road Towards Green RAN,” Dec. 2013

Easiest way to improve energy efficiency: more virtualization

Spectral Efficiency: Why MIMO?

Signal to Noise Ratio (S/N) Signal BW (Hz)

Capacity

(bits/second)

C = W N log2(1+SNR)

Number of Channels

•Use additional frequency bands in mmWave spectrum (24

to 110 GHz) for increased signal bandwidth up to 2 GHz

• Increase SNR of 5G waveforms and multiple access

• Implement Massive MIMO with multiple channels and

beamforming to improve SNR

Solutions: mmWave & Massive MIMO

Increased Capacity, Increased OPEX

Energy Efficiency: Why Massive?

Number of Antennas = 1

Number of BS transmit

antennas (Mt) 1

Normalized output power of

antennas

Normalized output power of

base station

Improve energy efficiency: more antennas

Number of UEs: 1

120 antennas per UE

120

...

PBS = 1 PBS = 0.008

Wasted

power

Source: IEEE Signal Processing Magazine, Jan 2013

Massive MIMO Beamforming Architectures

Analog Beamforming (ABF)

PA

ABF

Phase

shifters

N = 1

Ant 1

Ant M

...

N = 1, M antennas

Ant 1

...

Ant p

Ant q

...

Ant M

Digital Beamforming (DBF)

N TRx = M antennas

TRx 1 Ant 1

Ant M

DBF

Base-

band

beam-

forming

TRx N

Hybrid Beamforming (HBF)

N < M

From Analog .... ... To Digital

p

Probe

gm Cm

mth antenna circulator or switch

Measurement

equipment

Receive RF chain

Transmit RF chain Tn

Rn

nth TRx module Single Transceiver + Antenna

... To Hybrid

x(t)

x1(t)

xN(t)

TRx 1

DBF

Base-

band

beam-

forming

TRx N

x1(t)

xN(t)

ABF

1

ABF

N

Hardware Perspective: Massive MIMO = Beamforming + MIMO

M =

4 T

ransc

eiver

s x3(t)

x1(t)

x2(t)

x4(t)

MIMO Array: M Data Streams Beamforming Array: 1 Data Stream

x1(t) TRx +

Multi-User MIMO Increase SINR and capacity for each user

i.e. UE1: 16 ant BF with 16x2 MIMO

UE2: 32 ant BF with 8x2 MIMO

Massive arrays of 128 to 1024 active antenna elements

Massive MIMO: Combine Beamforming + MIMO = MU-MIMO with M antennas >> # of UEs

Massive MIMO Challenges

Data

Bottleneck

Calibration Mutual

Coupling Irregular

Arrays

Reduced MU-MIMO Reduced Capacity Grating Lobes Increased Costs

CPRI Bottleneck

Complexity

Increased Costs

RFIC

FPGA

Digital IQ

TR

x

RFIC

Active Antenna Arrays: The Calibration Problem

Phase/Magnitude/Frequency Tolerances (Static & Dynamic)

RFIC RFIC

LO FPGA

Digital IQ

RF Feeding Network

Dynamic Thermal Effects in PAs

Timing Errors in ADCs

Frequency Drift Between Modules

General

Manufacturing Tolerances of

Components & Thermal Effects

Phase Shifter Tolerances

Group Delay Variations

Mutual Coupling vs. Network Capacity Solution: Measurement with multi-port VNA

Up to 288 elements

0.4λ 1.2λ

Source: Signal Processing Magazine, IEEE, Jan 2013

In order to maintain capacity, square antenna arrays require

more spacing to reduce antenna mutual coupling

R&S®ZNBT

All S-parameters

0 to 8.5 GHz

Problem: Antenna mutual coupling reduces capacity

True simultaneous 24-port measurement

+ R&S®ZN-Z84

Massive MIMO = Complex Basestations

Wideband: PA

and Filter Banks

Mutual Coupling

Isolation

Adaptive Self-

Calibration

Fiber Multiplexing

mmWave = Non-

CMOS components

Beamforming

Architecture

128 element AAS prototypes: Complexity increased by 8 times

LO FPGA

Digital IQ

RFIC

Heat

Dissipation

Clock

Synchronization

Fiber

Transceivers

Receiver +

DSP/FPGA

RFIC

Passive vs. Active Antennas: Why OTA?

Passive Antenna Active Antenna

Outer enclosure: Radome

Antenna + Feeding Network

Outer enclosure

RF I/O ports

Outer enclosure: Radome

Antenna + Feeding Network

Outer enclosure

RF Transceiver Boards + Filters

Shielding + Heatsink

CPRI + FPGA Board

Input/Output: Radiated Signal

Input/Output: RF Signal Input/Output: Digital IQ BB Data

Input/Output: Radiated Signal

Front Radome

Rear Radome/Heatsink

Basestation Field Distributions

Basestation 8 Element Array at 2.69 GHz

Near-field region

phase & magnitude

Required chamber size for far-field

AUT size (D) Frequency Chamber size

0.5 meters 6 GHz 10 meters

0.5 meters 30 GHz 50 meters

1.0 meter 6 GHz 40 meters

Very near-field

region (< 0.6m)

Near: Phase + Magnitude Far: Magnitude

Far-field vs. near-field

Far field

magnitude

2D2 / λ = 4.1 m

OTA Measurements for 5G Active & Passive Antennas

Reference

Antenna

Measurement

Antenna

Active

Antenna

System

DUT

Phase Shifter

φ = [0, ± π/2, π]

Frequency range: 0.4 to 110 GHz

Passive Antenna

Measurements Active

Antennas

R&S®ZVA

R&S®SMW200A

R&S®ZVA

Measurement Setup for 3D Antenna Pattern: 24 GHz DUT

Shielded Chamber

R&S®DST200

R&S®FSW Signal and

Spectrum Analyzer

Measurement Equipment

R&S®AMS32

Measurement SW

Measurement Scenarios

OTA measurements for R&D and sample testing in production

Benchtop Beamforming

Measurements: R&S®TS7124

Shielded chamber

(R&S®TS7124)

Vivaldi probe

27.5 to 75 GHz

Measurement Equipment

Measurement Scenarios

60 GHz (and mmWave) will not have antenna connectors

OTA measurements will be mandatory for production

R&S®NRPM

2D Beam-Steering 3D Beam-Steering

R&S®TS7124

RF antenna array

beam forming/

electronic sector

selection

“If you want to go fast, go alone.

If you want to go far, go together!” African proverb