Transcript WiMAX

‫به نام خدا‬
An Overview of
Next Generation of Mobile WiMAX Technology
(802.16m)
.:. Class seminar .:.
Lecturer: Mohammad Aliasgari
Class presentation for the course: “Custom Implementation of DSP Systems”
All the materials are copy rights of their respective authors as listed in references.
Custom Implementation of DSP system
Spring 2010
Tehran University
1
Outline
Introduction
IEEE 802.16m
Mobile Wimax reference model
Protocol structure
Mobile Station State Diagram
Frame Structure
Modulation & Coding & Duplexing
Multi Antenna Technique in 802.16m
Reference
Custom Implementation of DSP system
Spring 2010
Tehran University
2
Introduction (Wireless Network)
Mobile
(e.g. GPRS)
Wireless
Network
Point to point
Fixed
Point to Multipoint
(e.g. 802.11)
Fig1. PTMP Network example [7]
Mobile 802.16e
Wimax
Fixed
802.16 (2004)
Custom Implementation of DSP system
Spring 2010
Tehran University
3
Introduction (Wimax : Fixed vs. Mobile)
[2]
Custom Implementation of DSP system
Spring 2010
Tehran University
4
Introduction (Terminology)
•BS: Base Station
•MS: Mobile Station
Cell configuration [7]
•Handover: In satellite communications it is the process of transferring
satellite control responsibility from one earth station to another without loss or
interruption of service. [8]
•Downlink: transmission channel that carries signals from a Base station
transmitter to mobile station.
•Uplink: transmission channel which carries signals from a mobile station to a
base station.
Custom Implementation of DSP system
Spring 2010
Tehran University
5
IEEE 802.16m
Since January 2007, the IEEE 802.16 Working Group has embarked on the
development of a new amendment of the IEEE 802.16 standard (i.e., IEEE
802.16m) as an advanced air interface to meet the requirements of the
International Telecommunication Union— Radio communication / International
Mobile Telecommunications (ITUR / IMT) [1]
Main Features [5]:
•Data transfer rates over the air excess of 1 Gb /s .
•Full compatible with existing Mobile wimax systems.
•Time to market advantage over other mobile broadband wireless technologies
•Enable roaming and seamless connectivity across IMT advanced requirements.
•Improving Coverage & performance by utilizing Multi hop relay architectures.
Custom Implementation of DSP system
Spring 2010
Tehran University
6
IEEE 802.16m & IMT-Advanced requirements
IEEE 802.16m & IMT-Advanced requirements [1]
Custom Implementation of DSP system
Spring 2010
Tehran University
7
Mobile Wimax reference model
•The reference system is defined as a system that compliant with IEEE802.16e
•Wimax network architecture specifies an end to end network.
Mobile WiMAX reference model [9]
Custom Implementation of DSP system
Spring 2010
Tehran University
8
Reference model
The WiMAX network reference model is composed of four logical parts:
[1]
• Mobile Stations (MS) , Comprises all user.
• Network Access Provider (NAP), Some of the functions included in the NAP
are: access service network (ASN), 802.16 interface with network entry and
handover, base stations, foreign agent, QoS and policy enforcement .
• Network Service Provider (NSP), Provides IP connectivity services. Some of
the functions included within the NSP are: connectivity service network (CSN),
home agent (HA), connectivity to the Internet, IP address management,
authentication, authorization.
• Internet, Provides Internet content to a user.
Custom Implementation of DSP system
Spring 2010
Tehran University
9
IEEE 802.16m protocol structure
Special feature
For 802.16m
MAC Common Part
sub layer (MAC CPS)
----------------------------
MAC = {CPS} U {CS}
----------------------------
Physical + MAC Layer
data control management
plane plane plane
WiMAX Protocol structure [3]
Custom Implementation of DSP system
Spring 2010
Tehran University
10
Radio Resource control & management functions
Here is some of important block functions of this part [1]:
Mobility management: This block scans neighbor BSs and decides whether
an MS should perform a handover operation.
Network entry management: This block controls initialization and access
procedures and generates management messages during initialization and
access procedures.
Radio Resource control & management [3]
Custom Implementation of DSP system
Spring 2010
Tehran University
11
Radio Resource control & management functions
System configuration management: This block manages systemconfiguration parameters and generates broadcast-control messages, such as a
DL/UL channel descriptor.
Connection management: This block allocates connection identifiers (CIDs)
during initialization/handover service-flow creation procedures.
Location management: This block supports location-based service (LBS),
generates messages including the LBS information, and manages the locationupdate operation during idle mode.
Idle mode management: This block controls idle-mode operation and
generates the paging-advertisement message .
Custom Implementation of DSP system
Spring 2010
Tehran University
12
MAC functions
Here is some of important block functions of this part [1]:
Sleep mode management: This block handles sleep mode operation and
generates management messages related to sleep operation and can
communicate with the scheduler block to operate properly according to the sleep
period.
Quality of service : This block performs rate control based on QoS input
parameters from the connection management function for each connection.
Scheduling & resource mplexing: This block schedules and multiplexes packets
based on the properties of the connections.
Automatic repeat request : This block performs the MAC ARQ function.
Fragmentation/packing : This block performs the fragmentation or packing of
MSDUs based on input from the scheduler block.
Custom Implementation of DSP system
Spring 2010
Tehran University
13
802.16m special features
New features for 802.16m standard [1]:
Relay function: Relay functionality and packet routing in relay networks.
Self organization & self optimization : a plug-and-play form of operation for
an indoor BS.
Multi carrier function: Control and operation of a number of adjacent or
non-adjacent radio-frequency (RF) carriers where the RF carriers can be
assigned to unicast and/or multicast and broadcast services.
Custom Implementation of DSP system
Spring 2010
Tehran University
14
Generalization of protocol structure for 802.16m
From perspective of MS, the carrier utilize
In multi carrier system can divided into two
categories: [1]
A primary RF carrier is the carrier that is used
by the BS & the MS to exchange traffic & full
PHY/MAC control information.
A secondary RF carrier is an additional
carrier that the BS may use for traffic
allocations for mobile stations capable of
multicarrier support.
Multi carrier system [1]
Custom Implementation of DSP system
Spring 2010
Tehran University
15
IEEE 802.16m Mobile Station State Diagram
A mobile state diagram is a
set of state and procedures
which MS transits when
operating in the system.
Special feature for 802.16m
IEEE 802.16m State diagram [1]
Custom Implementation of DSP system
Spring 2010
Tehran University
16
IEEE 802.16m Mobile Station State Diagram[1]
Initialization state: A state where an MS without any connection performs cell
selection by scanning and synchronizing to a BS preamble and acquires the systemconfiguration information through the DL and UL channel descriptors.
Access state: A state where the MS performs network entry to the selected BS. The MS
performs the initial ranging process to obtain UL synchronization. Next, the MS performs
basic capability negotiation with the BS. Then, the MS performs the authentication and
authorization procedure. Next, the MS performs the registration process. The mobile
station receives user identification as part of the access-state procedures.
Connected state: A state consisting of the following modes: sleep mode, active mode,
and scanning mode. During the connected state, the MS maintains at least one
connection as established during the access state, of the MS, the MS or the BS can
request a transition to sleep mode. Also, the MS can scan neighbor BSs to reselect a cell
that provides more robust and reliable services.
Custom Implementation of DSP system
Spring 2010
Tehran University
17
IEEE 802.16m Mobile Station State Diagram
Idle state: state comprising two separate modes, paging-available mode and paging
unavailable mode. During the idle state, the MS can attempt power saving by switching
between paging-available mode and paging-unavailable mode. In the paging-available
mode, the MS can be paged by the BS.
Custom Implementation of DSP system
Spring 2010
Tehran University
18
Frame Structure : Super Frame[1]
Super Frame is new concept introduced in IEEE 802.16m
Radio frame
to decrease the air link access Latency,
each radio frames are Divided into a
number of sub frames
six OFDMA symbols
seven OFDMA symbols
Super frame structure [1]
five OFDMA symbols
By this structure, air link access latency reduce from 18.5 ms to less than 5 ms .[5]
Custom Implementation of DSP system
Spring 2010
Tehran University
19
Modulation , Coding ,Multiplexing & Duplexing
Multiplexing: OFDM
IEEE 802.16 (e & m) >> OFDMA (1024 subcarrier) , SOFDMA (variable subcarrier)
Frequency Division Multiplexing [10]
Orthogonal Frequency Division Multiplexing [10]
Orthogonal Frequency Division Multiple Access [11]
Custom Implementation of DSP system
Spring 2010
Tehran University
20
Modulation , Coding ,Multiplexing & Duplexing
IEEE 802.16m supports quadrature - phase shift keying (QPSK), 16-QAM, and
64-QAM modulation schemes in the DL and UL .
For having lower error packet
rate, except Adaptive Modulation
, IEEE 802.16m use Constellation
diagram Rearrangement in
retransmission [1]
A constellation diagram for 8-PSK. [12]
A constellation diagram for
rectangular 16-QAM. [12]
A constellation diagram is a representation of a signal modulated by a digital modulation
scheme such as quadrature amplitude modulation. It displays the signal as a twodimensional scatter diagram in the complex plane at symbol sampling instants. [12]
Custom Implementation of DSP system
Spring 2010
Tehran University
21
Modulation , Coding ,Multiplexing & Duplexing
Coding
A convolutional Code (convolutional Turbo Code) is
a type of error-correcting code in which each m-bit
information symbol (each m-bit string) to be
encoded is transformed into an n-bit symbol,
where m/n is the code rate (n ≥ m). [13]
[1]
Custom Implementation of DSP system
Spring 2010
Tehran University
22
Modulation , Coding ,Multiplexing & Duplexing
Duplexing: A duplex communication system is a system composed of two connected
parties or devices that can communicate with one another in both directions. [1]
-TDD: time division Duplexing
-FDD: Frequency division duplexing
-HFDD
Structure of advanced preamble[4]
Custom Implementation of DSP system
Spring 2010
Tehran University
23
Multi Antenna Technique in 802.16m
Spatial multiplexing for increasing capacity of channel
Multi Antenna scheme[6]
Custom Implementation of DSP system
Spring 2010
Tehran University
24
Multi Antenna Technique in 802.16m
Illustration of DL MIMO structure [1]
Custom Implementation of DSP system
Spring 2010
Tehran University
25
Reference
[1] Sassan Ahmadi, Intel Corporation, “An Overview of Next-Generation Mobile WiMAX Technology”,
IEEE Communications Magazine, June 2009
[2] WiMAX Forum, “Mobile System Profile, Release 1.0 Approved Specification” ,May 2010 ;
http://www.wimaxforum.org/technology/documents
[3] IEEE 802.16m-08/003r7, “IEEE 802.16m System Description Document” , May 2010 ;
http://ieee802.org/ 16/tgm/index.html
[4] Frank, A Ibikunle, "Security Issues in Mobile WiMAX (IEEE 802.16e)", 2009 IEEE Mobile WiMAX
Symposium
[5] Klodiana Zaka, Naveed Ahmed, M Ibrar-ul-Haq, M. Irfan Anis, Basil Faria, “Performance Analysis and
Throughput Optimization in IEEE 802.16 WiMax Standard”, IEEE2009
[6] http://en.wikipedia.org/wiki/MIMO#Multi-user_types , May 2010
[7] http://www.wimax.com/commentary/wimax_weekly/1-2-fixed-broadband-wireless-market-driversand-applications , May 2010
[8] http://en.wikipedia.org/wiki/Handover , May 2010
[9] WiMAX Forum, “Network Architecture Stage 2–3,” Rel.1, v. 1.2, May 2010;
http://www.wimaxforum.org/technology/documents ,May 2010
[10] http://plcmodems.blogspot.com/2006/01/ofdm_20.html , May 2010
[11] www.conniq.com/WiMAX , May 2010
[12] http://en.wikipedia.org/wiki/Constellation_diagram , May 2010
[13] http://en.wikipedia.org/wiki/Convolutional_code ,May 2010
Custom Implementation of DSP system
Spring 2010
Tehran University
26