Mobile Communications Systems

1

• Mobile Communications Systems

2
Mobile Communications

• Principle of Operation
• Frequency reuse - cell
• Cluster - Interference
• Sector - Directional antenna
• Hand off across boundary
• Mobile switching
• PSTN
• Issues
• Co-channel interference
• Adjacent channel rejection
• Multi-path and fading

http//www.privateline.com/Cellbasics/Cellbasics.h
tml
3
Mobile Communications History

• 1976 - Bell Mobile Phone
• 1979 - NTT/Japan
• 1983 - Advanced Mobile Phone System (AMPS)
• 850 MHz, 50 MHz bandwidth
• FDMA, 30 kHz channel, 832 channels
• 1989 - Groupe Spècial Mobile in Europe
• 900 MHz
• 200 kHz channel, TDMA by 8 users
• 1991 - Digital Cellular System (DCS)
• 1.8 GHz
• 1993 - Code-Division Multiple-Access (CDMA)
• 1.25 MHz channel
• 1994 - GSM in US, Global System for Mobile
  Communications''
• 1995 Personal Communications Services (PCS)
• 1.9 GHz, 120 MHz bandwidth
• 2000 - 3G

4
Mode

• Analog
• AMPS
• Digital
• TDMA (IS-54)
• GSM and DCS 1800
• http//www.iec.org/online/tutorials/gsm/
• CDMA (IS-95, CDMA2000, 1xEV)
• IDEN
• Voice coder
• http//people.qualcomm.com/karn/voicedemo/

5
Signaling

• AMPS
• 30 kHz band 1 user frequency reuse 7
• FM, FSK
• TDMA
• 30 kHz band 3 users frequency reuse 7
• DQPSK
• GSM
• 200 kHz band 8 users frequency reuse 3
• TDM
• GMSK
• http//www.emc.york.ac.uk/reports/linkpcp/appD.pd
  f
• CDMA
• 1.25 MHz band 20 users frequency reuse 1
• QPSK, OQPSK
• Power control http//www.cdg.org/technology/cdma_t
  echnology/a_ross/cdmarevolution.asp

6
Frequency Band

• North America
• 824-894 (850) MHz
• 1850-1990 (1900) MHz
• 806-869 MHz Nextel
• International
• 880-960 (900) MHz
• 1710-1880 (1800) MHz

7
Generation

• Analog Voice
• 1G
• Digital Voice and Data
• 2G
• 7-28.8 kbps
• 2.5G
• 50-144 kbps
• General Packet Radio Service
• Enhanced Data Rates for Global Evolution (EDGE)
• CDMA2000 1x
• 3G
• 384 kbps 2 Mbps
• Universal Mobile Communications System (UMTS)
• Evolution Data Only (EV-DO), Data and Voice
  (EV-DV)
• 4G
• http//www.mthr.org.uk/documents/meetings/nov_200
  2/speaker_abstracts/m_capstick.pdf

8
Handset

• Block Diagram
• Keypad
• Display
• RF
• Voice
• Data
• Interface
• Control
• Antenna
• Products
• http//www.lairdtech.com/pages/products/Centurion-
  Overview.asp?sourcewww.centurion.com
• Chipset
• RF transceiver, analog audio, digital data,
• application processor

9
Base Station

• Cellular Tower
• Directional Antenna
• Transceiver
• Base band
• Interface

10
Control

• Authentication, Authorization, and Accounting
• Database
• Home location register
• Visitor location register
• Equipment identifier
• Authentication

11
MIMO

• Muti Input and Multi Output
• Multiple antennas
• Space Time Code
• Reference
• http//ieeexplore.ieee.org/iel5/49/26726/01192168.
  pdf?tparnumber1192168isnumber26726

12
Alamouti Space Time Code
University of Newcastle
13

• Wireless Networking

14
Wireless Data and Networking

• Wi-Fi
• IEEE802.11b and g, 2.4 GHz
• IEEE802.11a, 5.2 GHz
• Introduction and signaling
• http//www.sss-mag.com/pdf/802_11g_whitepaper.pdf
• Bluetooth
• IEEE802.15.1
• Introduction
• http//www.wirelessdevnet.com/channels/bluetooth/f
  eatures/bluetooth.html
• Class 1 (20 dBm), 2 (4 dBm), 3 (0 dBm)
• Networking Piconet, Scatternet
• http//www.site.uottawa.ca/ivan/T3-bluetooth.pdf
• Zigbee
• http//www.zigbee.org/en/resources/SlidePresentat
  ions
• IEEE802.15.4
• Low cost

15
Comparison
 
http//www.firstcontactengineering.com/fce_compari
son.htm
16
Spectrum

• Industrial Scientific Medicine (ISM) Band
  2400-2483.5 MHz
• Interference
• http//www.mwee.com/showArticle.jhtml?articleID16
  3700631

17
Wireless Networks

• Security
• WAPI
• MIMO
• Dynamic Wireless Network With Extended Range
• Ad hoc
• Infrastructure
• Wireless Sensor Network
• Node Characteristics
• Low power
• Mobile
• Numerous

18

• Radio Frequency Identification

19
RFID

• Principle of Operation
• Active tag
• Passive tag
• Inductive coupling
• Back scattering
• Applications
• Inventory
• Access control
• Identification
• Smart card
• Toll collection
• Reference
• http//people.interaction-ivrea.it/c.noessel/RFID/
  RFID_research.pdf

20
Frequency and Applications
21
Components

• Reader
• Tag

22
Block Diagrams

• Tag

Universität Rostock
23
Block Diagrams

• Reader

Universität Rostock
24
Circuits

• Coil
• http//ww1.microchip.com/downloads/en/appnotes/006
  78b.pdf
• http//www.mwrf.com/Articles/Print.cfm?ArticleID5
  474
• Circuit
• http//www.linear.com/pc/downloadDocument.do?navId
  H0,C1,C1011,C1097,P2324,D11297

25
Issues

• Multi-Tag Collision
• Slotted Aloha
• Binary search
• Database Management
• http//www.oracle.com/technologies/rfid/index.html