Millimeter wave technology enables 5G communication by utilizing spectrum in the 30-300 GHz range. It allows for significantly wider channel bandwidths than 4G. Issues include high propagation losses that can be mitigated by beamforming and network densification. Initial 5G deployments may use a hybrid system with millimeter wave for high-speed data and 4G for control to address challenges like device power constraints. Narrow beams reduce interference but make initial access difficult, requiring techniques like MIMO. Building penetration is limited at millimeter wave frequencies.

1. Millimeter Wave
Millimeter Wave Enabling 5G Communication

2. Presented BY
Abdul Qudoos
BSEE(IIUI)
MSEE(FAST-NU)-In Progress

3. What Technologies will 5G contain/Introduced.
The three big technologies 5G will contain are mentioned below.
• Ultra-densification
• Millimeter wave
• MIMO(Multi-input-multi-output)

4. Basic/Expected Requirements for 5G
• Aggregate data rate or area capacity.
It is the total amount data the network can serve in bits/s per unit area.
This will increase 1000x from 4G to 5G.
• EDGE Rate or 5% rate.
It is the worst data rate an user except to receive with in network
coverage area. In 5G it will be vary from 100 Mbps to 1Gbps.However it
is very challenging as 4G users only get 5% of 100 Mbps in worst case
scenario.

5. Basic/Expected Requirements for 5G
• Peak Rate
Peak rate is the best data rate a user can receive which likely to be in the range of 10 of Gbps.
KEY TECHNOLOGIES TO GET TO 1000× DATA RATE
• Extreme densification and offloading to improve the area
spectral efficiency. Put differently, more active nodes per
unit area and Hz.
• Increased bandwidth, primarily by moving toward and
into mmWave spectrum but also by making better use
of WiFi’s unlicensed spectrum in the 5-GHz band. Altogether,
more Hz.
• Increased spectral efficiency, primarily through advances
in MIMO, to support more bits/s/Hz per node.

6. Millimeter Wave
• Millimeter wave range varies from 30-300 Ghz
• Millimeter wave spectrum would allow service providers to
significantly expand the channel bandwidth far beyond the 20 MHZ
channel as used by customers in 4G.

7. Why it was better than previous Technologies
• Millimeter wave was highly integrative with any any 5G air interface
and spectrum together with LTE and WIFI to provide high rate
coverage.
• In millimeter wave we use MIMO scheme which uses large number of
antennas for beamforming. Large number of antennas enable
transmitter and receiver beamforming with high gains.
• A beam at 80 GHz will have about 30 dB more gain (narrower beam)
than a beam at 2.4 GHz if the antenna areas are kept constant.

8. Why Millimeter wave
• 4G(LTE) is deployed and reaching maturity now with only small incremental
improvements were possible we have to move towards 5G.
• There is an need for network virtualization and greater energy efficiency.
• Terrestrial wireless networks have restricted their operations to the slim
range of microwave frequencies from several hundred MHZ to few Ghz
which corresponds to the wavelength in the range of few centimeters up to
about a meter.This spectrum is usually known as beachfront spectrum and
become fully occupied now.
• Moreover today cellular systems are limited to carrier frequency spectrum
ranging between 700MHz and 2.6 GHz which is fully saturated.

9. Issues related to millimeter wave/Propagation
Losses
• Path Loss:
If we increase carrier frequency in the range of 3GHZ to 300GHZ it will
add an path loss of 20DB regardless of the transmit receive distance.
Other main challenge was to control steer antennas so they can collect
or produce energy productively.
Blocking:
As the transmit-receive distance grows path loss should take place will
be 20DB/Decade(10 times increase in frequency)under LOS
propagation but drops to 40Db/Dacade plus an addltional blocking loss
of 15 to 20 db.

10. Conclusion related to propagation losses
• The propagation losses describe above will be controllable by using
steer antennas to use guided beam.

11. Issues/Challenges with Millimeter Wave
• Another challenge with millimeter-wave is the low efficiency of RF devices
such as power amplifiers and multi-antenna arrays with current
technology.
• A solution to avoid multi-antenna arrays at the MMB base station is to use
fixed beams or sectors with horn antennas.
• Horn antennas can provide similar gains and beam widths as sector
antennas in current cellular systems in a cost-effective manner.
• The mobile station receiver still needs to use a multi-antenna array to form
a beamforming pattern toward the base station.
• As the mobile station moves around, beamforming weights can be adjusted
so that the beam is always pointing toward the base station.

12. Issues/Challenges with Millimeter Wave
• However, the cost of implementing one RF chain per antenna can be
prohibitive, especially given the large number of antennas in MMB.
With analog baseband beamforming or RF beamforming, one or a few
RF chains can be used.
• In that case, the number of data streams that can be transmitted is
limited by the number of RF chains.
• These approaches require fewer RF components and are typically
chosen for low cost/low-power solutions.

13. Issues/Challenges with Millimeter Wave
• Moreover, due to low efficiency of millimeter-wave power amplifiers
with the current technology, battery power consumption is another
issue for mobile station transmitter beamforming.
• To reduce the cost and complexity of mobile stations, a phased
approach where initial deployments are hybrid MMB + 4G systems
with downlink-only transmission in the millimeter-wave band can be
considered.
• This removes the requirement for mobile stations to transmit in the
millimeter-wave band.

14. Narrow Beam Communication
• A wireless system build for narrow and focused beam is not simple
but it will mitigate the interference effects compared to the
traditional beamforming schemes.
• Millimeter waveform will use narrow beamforming scheme which will
decrease interference compared to 4G and their main concern is that
millimeter wave systems will left with noise limited system after
interference mitigation.
• A key challenge with narrow beam system is the difficulty in
establishing associations between user and BS’s both for initial access
and for handoff.

15. Narrow Beam
Communication
• As it is difficult to scan all the
angular positions to discover MS
by BS.This challenging problem is
solved by using multi input multi
output antennas(MIMO).

16. Combination of 3G and 4G to avoid above
problems(Hybrid + 4G System)
• All the problems described above can be mitigated using legacy 4G
network and 5G combined where we used small BSs with large legacy
base stations.
• Control plane will be control by legacy base stations and and data
transmission will be done through millimeter wave using phantom
cells and small basestations. If data lost during transmission it will
recover through retransmissions as control plane remain established
with microwave frequencies through main base stations.

17. Combination of 3G and 4G to avoid above
problems(Hybrid + 4G System)
• Initial synchronization signals including primary and secondary
synchronization signals will be communicate through legacy base station
which contains context information, received power and channel
information.
• There are three synchronization signals will be sent by the legacy base
station to the user equipment.
• After synchronization was done the legacy base station will inform the
user equipment about the millimeter wave cell and all the data
communication will held through millimeter base station.
• The connection between legacy base station and user equipment is done
through a plane called control plane and the connection between the
millimeter base station and the user is done through a plane called user
plane.

18. Combination of 3G and 4G to avoid above
problems(Hybrid + 4G System)

19. Hardware Issues
• As digital to analog converter and analog to digital converter requires
enormous bandwidth so it become unfeasible in case for digital
beamforming to design it for every antenna as we are implementing
MIMO in our millimeter wave communication.
• We can use an old fashion analog phase shifters and hybrid structures
where group of antennas only shared a single A/D.

20. Millimeter wave experiments in Manhattan &
New York

21. Millimeter wave
attenuation with rain
Intensity
• Raindrops are
roughly the same
size as theradio
wavelengths
(millimeters) and
therefore cause
scattering of the
radio signal.

22. Point to Ponder
• A mechanism such as supporting emergency communications over
cellular bands when millimeter-wave communications are disrupted
by heavy rains should be considered as part of the MMB system
design.
• MBB system has been briefed in coming slides.

23. Millimeter wave attenuation with rain intensity
• As Today cell size in urban environment is of the order 200 m so surely
millimeter wave will overcome the attenuation issues.
• As seen above the 25MM/hr rain which is equal to 1 inch/Hr will cause an
attenuation of 7db/km at 28 Ghz which is equal to 1.4db of attenuation for
the size of an cell approximately equal to 200m.
• Small cells can be used namely small excess points which decrease the
distance between transmitters an users which results in lower propagation
losses higher data rate and increase spectral efficiency.
• Moreover tiny wavelength of millimeter wave allow hundreds of antenna
elements to be placed in an array on a small area on base station and
smaal cells will ensure that mm-wave frequencies will overcome rain
attenuation.

24. 28 GHZ Building Penetration and reflection
Measurement
• Penetration and reaction measurements for com-mon materials were
conducted at three locations at the NY campus in New York City: (a)
the 10th floor of 2 MetroTechCenter (MTC) in Brooklyn, (b) the
Othmer Residence Hall(ORH) in Brooklyn, and (c) Warren Weaver Hall
(WWH) in Manhattan.

25. Penetration and Reflection Measurement

26. Conclusion
from above
figure
• This illustrates the fact that building penetration
of mm-waves will be difficult for outdoor
transmitters, thus pro-viding high isolation
between outdoor and indoor networks. On the
other hand, common indoor materials such as
clear non-tinted glass and drywall only have 3.6
dB and 6.8 dB of losses, respectively, which are
relatively low.

27. Experimental Place

28. MAP of
Penetration
Measurement

29. Conclusion
• As shown in Fig. 4,multiple indoor obstructions in an office building
environ-ment were characterized using 8 RX locations, in which each RX
location was selected to determine penetration through increasing layers
of obstructions. Partition layers included multiple walls, doors, cubicles,
and an elevator bank (RX 8) . We used lower TX power which limited the
maximum measurable path loss to about 169 dB.

30. Foliage Losses
• we plot penetration losses for
foliage depth of 5, 10, 20, and
40m. We note, for example,
that at 80 GHz frequency and
10 m foliage penetration, the
loss can be about 23.5 dB,
which is about 15 dB higher
than the loss at 3 GHz
frequency.

31. Doppler and Multipath
• Assuming a rich scattering environment and omnidirectional
antennas, the maximum Doppler shift for carrier frequency of 3–60
GHz with mobility of 3–350km/h ranges from 10 Hz to 20 kHz.
• The Dopplershift values of incoming waves on different angles at the
receiver are different, resulting in a phenomenon called Doppler
spread.
• In the case of MMB, the narrow beams at the transmitter and
receiver will significantly reduce angular spread of the incoming
waves, which in turn reduces the Doppler spread.

32. Doppler and Multipath
• Therefore, the time-domain variation of an MMB channel is likely to
be much less than that observed by omnidirectional antennas in a
rich scattering environment.
• With narrow transmitter and receiver beams, the multipath
components of millimeter waves are limited.
• Studies show that the root meansquare (RMS) of the power delay
profile (PDP)of a millimeter-wave channel in an urban environment is
1–10 ns, and the coherent bandwidth of the channel is around 10–
100 MHz

33. MMB Network
• with a site-to-site distance of 500 m
and a range of 1 km for an MMB link,
an MMB mobile station can access up
to 14 MMB base stations on the grid
• With the high density of MMB base
stations, the cost to connect every
MMB base station via a wired
network can be significant. One
solution to mitigate the cost (and
expedite the deployment)is to allow
some MMB base stations to connect
to the backhaul via other MMB base
stations

34. MBB Frame Structure

35. MBB Frame Structure
• The cyclic prefix (CP) is chosen to be 520 ns, which gives sufficient
margin in accommodating the longest path.
• The subcarrier spacing is chosen to be 480 kHz, small enough to stay
within the coherent bandwidth of most multipath channels expected
in MMB.