1. Professor Andrea Goldsmith
EE 359: Wireless Communications
Professor Andrea Goldsmith

2. Outline Course Basics Course Syllabus The Wireless Vision
Technical Challenges
Current Wireless Systems
Spectrum Regulation and Standards
Emerging Wireless Systems

3. Course Information* People
Instructor: Andrea Goldsmith, Packard 371, OHs: MW after class and by appt.
TAs: Mainak Chowdhury, and Milind Rao,
Discussion Tues 4-5 pm (televised) or 5-6pm
OHs: Tues after discussion (Mainak), Wed 5-6pm, Thur 9:30-10:30 (Milind), location TBA.
OHs (ideally via Piazza): Thursday 2-4 pm. Piazza website:
Class Administrator: Pat Oshiro, Packard 365, Homework dropoff: Th by 5 pm.
*See web or handout for more details

4. Course Information Nuts and Bolts
Prerequisites: EE279 or equivalent (Digital Communications)
Required Textbook: Wireless Communications (by me), CUP
Available at bookstore (out of stock) or Amazon
Extra credit for finding typos/mistakes/suggestions (2nd ed. soon!)
Supplemental texts on 1 day reserve at Engineering Library.
Class Homepage:
All handouts, announcements, homeworks, etc. posted to website
“Lectures” link continuously updates topics, handouts, and reading
Class Mailing List: (automatic for on-campus registered students).
Guest list for SCPD and auditors: send Mainak/Milind to sign up.
Sending mail to reaches me and TAs.

5. Course Information Policies
Grading: Two Options
No Project (3 units): HW – 30%, 2 Exams – 30%, 40%
Project (4 units): HWs- 20%, Exams - 25%, 30%, Project - 25%
HWs: assigned Thurs, due following Thurs 5pm (starts 9/25)
Homeworks lose 33% credit per day late, lowest HW dropped
Up to 3 students can collaborate and turn in one HW writeup
Collaboration means all collaborators work out all problems together
Unpermitted collaboration or aid (e.g. solns for the book or from prior years) is an honor code violation and will be dealt with strictly.
Exams:
Midterm week of 11/3. (It will be scheduled outside class time; the duration is 2 hours.) Final on 12/8 from 8:30-11:30 am.
Exams must be taken at scheduled time, unless a course conflicts

6. Course Information Projects
The term project (for students electing to do a project) is a research project related to any topic in wireless
Two people may collaborate if you convince me the sum of the parts is greater than each individually
A 1 page proposal is due 10/24 at 5 pm.
5-10 hours of work typical for proposal
Project website must be created and proposal posted there
The project is due by 5 pm on 12/6 (on website)
20-40 hours of work after proposal is typical for a project
Suggested topics in project handout
Anything related to wireless or application of wireless techniques ok.

7. Course Syllabus Overview of Wireless Communications
Path Loss, Shadowing, and Fading Models
Capacity of Wireless Channels
Digital Modulation and its Performance
Adaptive Modulation
Diversity
MIMO Systems
Multicarrier Modulation
Spread Spectrum
Intro to Wireless Networks (EE360)

8. No lectures Wed 9/24, Mon 10/20, Wed 11/12
Date
Topic
Required Reading
Introduction 1
9/22
Overview of Wireless Communications
Chapter 1 and Appendix D
Wireless Channel Models
2*-3
9/26*,9/29
Path Loss and Shadowing Models
Lec 2: Section 2.1 to 2.6
Lec 3: Section 2.7 to 2.10
4-5
10/1,10/6
Statistical Fading Models, Narrowband Fading
Lec 4: Section 3.1 to 3.2.1
Lec 5: Section 3.1 to 3.2 6
10/8
Wideband Fading Models
Section 3.2 to 3.3
Impact of Fading and ISI on Wireless Performance 7
10/13
Capacity of Wireless Channels
Chapter 4
8,9*,10
10/15,10/22, 10/24*
Digital Modulation and its Performance
Lec 8: Chapter 5
Lec 9-10: Chapter 6
Flat-Fading Countermeasures 11
10/27
Diversity
Chapter 7 12
10/29
Adaptive Modulation
Section 9.1 to 9.2 MT
Week of 11/3
Midterm (outside class time)
Chapters 2 to 7 13
11/3
Practical Considerations in Adaptive Modulation
Section 9.3
14,15,16*
11/5,11/10, 11/17
Multiple Input/Output Systems (MIMO)
Chapter 10 & Appendix C
ISI Countermeasures 17
11/19
Equalization, Multicarrier Systems
Chapter 18
11/21*
Multicarrier Modulation and OFDM
Chapter
Multiuser Systems 19
12/1
Spread Spectrum and CDMA
Chapter 13 20
12/3
Overview of multiuser systems & networks
Course summary
Sections 14.1 to 14.4, 15.1 to 15.2, 16.1 to 16.3
Final
12/8
8:30-11:30 am
No lectures Wed 9/24, Mon 10/20, Wed 11/12

9. Class Rescheduling
9/24 (this Wed) moved to 9/26 (this Fri), 9:30-10:45, 102 Thornton (w/donuts)
10/20 (Mon) rescheduled to Fri 10/24, tentatively 9:30-10:45am, 102 Thornton (w/donuts)
11/12 (Wed) rescheduled to Fri 11/21, tentatively 9:30-10:45am, 102 Thornton (w/donuts)
May have optional advanced topics lecture the last week of classes (evening or lunch, w/ pizza)

10. Wireless History Ancient Systems: Smoke Signals, Carrier Pigeons, …
Radio invented in the 1880s by Marconi
Many sophisticated military radio systems were developed during and after WW2
Cellular has enjoyed exponential growth since 1988, with almost 5 billion users worldwide today
Ignited the wireless revolution
Voice, data, and multimedia ubiquitous
Use in third world countries growing rapidly
Wifi also enjoying tremendous success and growth
Wide area networks (e.g. Wimax) and short-range systems other than Bluetooth (e.g. UWB) less successful

11. Future Wireless Networks
Ubiquitous Communication Among People and Devices
Next-generation Cellular
Wireless Internet Access
Wireless Multimedia
Sensor Networks
Smart Homes/Spaces
Automated Highways
In-Body Networks
All this and more …

12. Challenges Network Challenges Device Challenges
Scarce/bifurcated spectrum
Demanding/diverse applications
Heterogeneous networks
High-performance requirements
Reliability and coverage
Device Challenges
Size, Power, Cost
Multiple Antennas in Silicon
Multiradio Integration
Coexistance
Cellular
Apps
Processor BT
Media
GPS
WLAN
Wimax
DVB-H
FM/XM

13. Software-Defined (SD) Radio:
Is this the solution to the device challenges? BT
A/D
FM/XM
Cellular
GPS
A/D
DVB-H
DSP
Apps
Processor
A/D
WLAN
Media
Processor
Wimax
A/D
Wideband antennas and A/Ds span BW of desired signals
DSP programmed to process desired signal: no specialized HW
Today, this is not cost, size, or power efficient
Compressed sensing may be a solution for sparse signals

14. Current Wireless Systems
Cellular Systems
Wireless LANs
WiGig and mmWave Communications
Cognitive Radios
Satellite Systems
Zigbee radios

15. Driving Constraint in Wireless System Design: Scarce Spectrum
$$$
Licensed Bands Scarce & Expensive

16. Spectral Reuse Due to its scarcity, spectrum is reusedBS
In licensed bands
and unlicensed bands
Wifi, BT, UWB,…
Cellular
Reuse introduces interference

17. Cellular Systems: Reuse channels to maximize capacity
Geographic region divided into cells
Frequency/timeslots/codes reused at spatially-separated locations.
Co-channel interference between same color cells (reuse 1 common now).
Base stations/MTSOs coordinate handoff and control functions
Shrinking cell size increases capacity, as well as networking burden
BASE
STATION
MTSO

18. Future Cellular Phones
Burden for this performance is on the backbone network
Everything wireless in one device BS
Phone
System
San Francisco
Paris
Nth-Gen
Cellular
Internet
LTE backbone is the Internet
Much better performance and reliability than today
- Gbps rates, low latency, 99% coverage indoors and out

19. 4G/LTE Cellular Much higher data rates than 3G (50-100 Mbps)
3G systems has 384 Kbps peak rates
Greater spectral efficiency (bits/s/Hz)
More bandwidth, adaptive OFDM-MIMO, reduced interference
Flexible use of up to 100 MHz of spectrum
20 MHz spectrum allocation common
Low packet latency (<5ms).
Reduced cost-per-bit
All IP network

20. Careful what you wish for…
Exponential Mobile Data Growth
Leading to massive spectrum deficit
Source: FCC
Source: Unstrung Pyramid Research 2010
Growth in mobile data, massive spectrum deficit and stagnant revenues require technical and political breakthroughs for ongoing success of cellular

21. Number of Connected Objects Expected to Reach 50bn by 2020
On the Horizon:
“The Internet of Things”
Number of Connected Objects Expected to Reach 50bn by 2020

22. Are we at the Shannon limit of the Physical Layer?
We don’t know the Shannon capacity of most wireless channels
Time-varying channels with no/imperfect CSI
Channels and networks with feedback
Channels with delay/energy/HW constraints.
Channels with interference or relays
Cellular systems
Ad-hoc/peer-to-peer networks
Multicast/common information networks

23. Rethinking “Cells” in Cellular
How should cellular
systems be designed?
Coop
MIMO
Small
Cell
Relay
Will gains in practice be
big or incremental; in
capacity or coverage?
DAS
Traditional cellular design “interference-limited”
MIMO/multiuser detection can remove interference
Cooperating BSs form a MIMO array: what is a cell?
Relays change cell shape and boundaries
Distributed antennas move BS towards cell boundary
Small cells create a cell within a cell
Mobile cooperation via relays, virtual MIMO, network coding.

24. Are small cells the solution to increase cellular system capacity?
Yes, with reuse one and adaptive techniques (Alouini/Goldsmith 1999)
A=.25D2p
Area Spectral Efficiency
S/I increases with reuse distance (increases link capacity).
Tradeoff between reuse distance and link spectral efficiency (bps/Hz).
Area Spectral Efficiency: Ae=SRi/(.25D2p) bps/Hz/Km2.

25. 10x CAPACITY Improvement
The Future Cellular Network: Hierarchical Architecture
Today’s architecture
3M Macrocells serving 5 billion users
Anticipated 1M small cells per year
10x Lower COST/Mbps (?)
10x CAPACITY Improvement
Near 100% COVERAGE
MACRO: solving initial coverage issue, existing network
PICO: solving street, enterprise & home coverage/capacity issue
Macrocell
Picocell
Femtocell
Future systems require Self-Organization (SON) and WiFi Offload

26. SON Premise and Architecture
Mobile Gateway
Or Cloud
Node Installation
Initial Measurements
Self Optimization
Self Healing
Self Configuration
Measurement
SON
Server
SoN Server
IP Network X2 X2 SW
Agent X2 X2
SON is part of 3GPP/LTE standard
Small cells not widely deployed today
Small cell BS
Macrocell BS

27. Green” Cellular Networks
Pico/Femto
How should cellular
systems be redesigned
for minimum energy?
Coop
MIMO
Relay
DAS
Research indicates that
significant savings is possible
Minimize energy at both the mobile and base station via
New Infrastuctures: cell size, BS placement, DAS, Picos, relays
New Protocols: Cell Zooming, Coop MIMO, RRM, Scheduling, Sleeping, Relaying
Low-Power (Green) Radios: Radio Architectures, Modulation, coding, MIMO

28. Wifi Networks Multimedia Everywhere, Without Wires
Wifi is today’s small cell
802.11ac
Streaming video
Gbps data rates
High reliability
Coverage inside and out
Wireless HDTV
and Gaming

29. Wireless Local Area Networks (WLANs)
1011
0101
Internet
Access
Point
WLANs connect “local” computers (100m range)
Breaks data into packets
Channel access shared (random access + backoff)
Backbone Internet provides best-effort service
Poor performance in some apps (e.g. video)

30. Wireless LAN Standards
802.11b (Old – 1990s)
Standard for 2.4GHz ISM band (80 MHz)
Direct sequence spread spectrum (DSSS)
Speeds of 11 Mbps, approx. 500 ft range
802.11a/g (Middle Age– mid-late 1990s)
Standard for 5GHz band (300 MHz)/also 2.4GHz
OFDM in 20 MHz with adaptive rate/codes
Speeds of 54 Mbps, approx ft range
802.11n/ac (Current)
Standard in 2.4 GHz and 5 GHz band
Adaptive OFDM /MIMO in 20/40/80/160 MHz
Antennas: 2-4, up to 8
Speeds up to 600Mbps/10 Gbps, approx. 200 ft range
Other advances in packetization, antenna use, multiuser MIMO
Many
WLAN
cards
have
(a/b/g/n)

31. Why does WiFi performance suck?
Carrier Sense Multiple Access:
if another WiFi signal
detected, random backoff
Collision Detection: if collision
detected, resend
The WiFi standard lacks good mechanisms to mitigate interference, especially in dense AP deployments
Multiple access protocol (CSMA/CD) from 1970s
Static channel assignment, power levels, and carrier sensing thresholds
In such deployments WiFi systems exhibit poor spectrum reuse and significant contention among APs and clients
Result is low throughput and a poor user experience

32. Why not use SoN for WiFi?
- Channel Selection
- Power Control
- etc.
SoN
Controller
SoN-for-WiFi: dynamic self-organization network software to manage of WiFi APs.
Allows for capacity/coverage/interference mitigation tradeoffs.
Also provides network analytics and planning.

33. In fact, why not use SoN for all wireless networks?
TV White Space &
Cognitive Radio
Vehicle networks
mmWave networks

34. Software-Defined Wireless Network (SDWN) Architecture
Video
App layer
Security
Vehicular
Networks
M2M
Health
Freq.
Allocation
Power
Control
Self
Healing
ICIC
QoS
Opt. CS
Threshold
SW layer
UNIFIED CONTROL PLANE
HW Layer
WiFi
Cellular
mmWave
Cognitive Radio

35. WiGig and mmWave WiGig mmWave Standard operating in 60 GHz band
Data rates of 7-25 Gbps
Bandwidth of around 10 GHz (unregulated)
Range of around 10m (can be extended)
Uses/extends MAC Layer
Applications include PC peripherals and displays for HDTVs, monitors & projectors
mmWave
Couples 60GHz with massive MIMO and better MAC
Promises long-range communication w/Gbps data rates
Hardware, propagation and system design challenges
Much research on this topic today

36. Satellite Systems Cover very large areas Different orbit heights
GEOs (39000 Km) versus LEOs (2000 Km)
Optimized for one-way transmission
Radio (XM, Sirius) and movie (SatTV, DVB/S) broadcasts
Most two-way systems went bankrupt
Global Positioning System (GPS) ubiquitous
Satellite signals used to pinpoint location
Popular in cell phones, PDAs, and navigation devices

37. IEEE 802.15.4/ZigBee Radios Low-Rate WPAN
Data rates of 20, 40, 250 Kbps
Support for large mesh networking or star clusters
Support for low latency devices
CSMA-CA channel access
Very low power consumption
Frequency of operation in ISM bands
Focus is primarily on low power sensor networks

38. Spectrum Regulation Spectrum a scarce public resource, hence allocated
Spectral allocation in US controlled by FCC (commercial) or OSM (defense)
FCC auctions spectral blocks for set applications.
Some spectrum set aside for universal use
Worldwide spectrum controlled by ITU-R
Regulation is a necessary evil.
Innovations in regulation being considered worldwide
in multiple cognitive radio paradigms

39. Standards Interacting systems require standardization
Companies want their systems adopted as standard
Alternatively try for de-facto standards
Standards determined by TIA/CTIA in US
IEEE standards often adopted
Process fraught with inefficiencies and conflicts
Worldwide standards determined by ITU-T
In Europe, ETSI is equivalent of IEEE
Standards for current systems are summarized in Appendix D.

40. Emerging Systems* Cognitive radio networks
Ad hoc/mesh wireless networks
Sensor networks
Distributed control networks
The smart grid
Biomedical networks
*Can have a bonus lecture on this topic late in the quarter if there is interest

41. Cognitive Radios
CRRx
NCRRx
NCRTx
CRTx
NCR IP CR
MIMO Cognitive Underlay
Cognitive Overlay
Cognitive radios support new users in existing crowded spectrum without degrading licensed users
Utilize advanced communication and DSP techniques
Coupled with novel spectrum allocation policies
Multiple paradigms
(MIMO) Underlay (interference below a threshold)
Interweave finds/uses unused time/freq/space slots
Overlay (overhears/relays primary message while cancelling interference it causes to cognitive receiver)

42. Compressed Sensing in Communications
Compressed sensing ideas have found widespread application in signal processing and other areas
Basic premise: exploit sparsity to approximate high-dimensional system/signal in a few dimensions.
We ask: how can sparsity be exploited to reduce the complexity of communication system design
Sparse signals: e.g. white-space detection
Sparse samples: e.g. sub-Nyquist sampling
Sparse users: e.g. reduced-dimension multiuser detection
Sparse state space: e.g reduced-dimension network control

43. Ad-Hoc Networks Peer-to-peer communications Routing can be multihop.
No backbone infrastructure or centralized control
Routing can be multihop.
Topology is dynamic.
Fully connected with different link SINRs
Open questions
Fundamental capacity region
Resource allocation (power, rate, spectrum, etc.)
Routing
-No backbone: nodes must self-configure into a network.
-In principle all nodes can communicate with all other nodes, but multihop routing can reduce the interference associated with direct transmission.
-Topology dynamic since nodes move around and link characteristics change.
-Applications: appliances and entertainment units in the home, community networks that bypass the Internet. Military networks for robust flexible easily-deployed network (every soldier is a node).

44. Wireless Sensor Networks
Data Collection and Distributed Control
Smart homes/buildings
Smart structures
Search and rescue
Homeland security
Event detection
Battlefield surveillance
Energy (transmit and processing) is the driving constraint
Data flows to centralized location (joint compression)
Low per-node rates but tens to thousands of nodes
Intelligence is in the network rather than in the devices

45. Distributed Control over Wireless
Automated Vehicles
- Cars
- Airplanes/UAVs
- Insect flyers
Interdisciplinary design approach
Control requires fast, accurate, and reliable feedback.
Wireless networks introduce delay and loss
Need reliable networks and robust controllers
Mostly open problems
: Many design challenges

46. The Smart Grid: Fusion of Sensing, Control, Communications
Open problems:
- Optimize sensor placement in the grid
- New designs for energy routing and distribution
- Develop control strategies to robustify the grid
- Look at electric cars for storage and path planning
carbonmetrics.eu

47. Applications in Health, Biomedicine and Neuroscience
Neuro/Bioscience
EKG signal reception/modeling
Brain information theory
Nerve network (re)configuration
Implants to monitor/generate signals
In-brain sensor networks
SP/Comm applied to bioscience
Body-Area
Networks
Doctor-on-a-chip
Wireless
Network
Recovery from
Nerve Damage

48. Main Points
The wireless vision encompasses many exciting systems and applications
Technical challenges transcend across all layers of the system design.
Existing and emerging systems provide excellent quality for certain applications but poor interoperability.
Innovative wireless design needed for mmWave systems, massive MIMO, SDWN, and Internet of Things connectivity
Standards and spectral allocation heavily impact the evolution of wireless technology