November 2005
doc.: IEEE 802.22-05/0109r1
[WRAN PHY/MAC Proposal for TDD/FDD]
IEEE P802.22 Wireless RANs
Date: 2005-11-17
Authors:
Name
Company
Address
Phone
email
Chang-Joo Kim ETRI
Korea
+82-42-860-1230 cjkim@etri.re.kr
Hak-Sun Kim
Samsung
Electro-mechanics
Korea
+82-31-210-3500 hszic.kim@samsung.c
om
Joy Laskar
Georgia Institute
of Technology
USA
+1-404-894-5268 joy.laskar@ece.gatech
.edu
Notice: This document has been prepared to assist IEEE 802.22. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in
this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein.
Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE
Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit
others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.22.
Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures http://standards.ieee.org/guides/bylaws/sb-bylaws.pdf including the
statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to
patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard
is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair
Carl R. Stevenson as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being
developed within the IEEE 802.22 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at patcom@iee.org.
>
Submission
Slide 1
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Co-Authors
Name
Company
Address
Phone
email
Myung-Sun Song
ETRI
Korea
+82-42-860-5046
mssong@etri.re.kr
Soon-Ik Jeon
ETRI
Korea
+82-42-860-5947
sijeon@etri.re.kr
Gwang-Zeen Ko
ETRI
Korea
+82-42-860-4862
gogogo@etri.re.kr
Sung-Hyun Hwang
ETRI
Korea
+82-42-860-1133
shwang@etri.re.kr
Soon-Soo Oh
ETRI
Korea
+82-42-860-4974
ssoh@etri.re.kr
Bub-Joo Kang
ETRI
Korea
+82-42-860-5446
kbj64370@etri.re.kr
Chung Gu Kang
ETRI
Korea
+82-2-3290-3236
ccgkang@korea.ac.kr
KyungHi Chang
ETRI
Korea
+82-32-860-8422
khchang@inha.ac.kr
Yoan Shin
ETRI
Korea
+82-2-820-0632
yashin@e.ssu.ac.kr
Yun Hee Kim
ETRI
Korea
+82-31-201-3793
yheekim@khu.ac.kr
Kyesan Lee
ETRI
Korea
+82-31-201-2032
kyesan@khu.ac.kr
Moon Ho Lee
ETRI
Korea
+82-63-270-2463
moonho@chonbuk.ac.kr
Jeong Suk Lee
Samsung Electro-Mechanics
Korea
+82-31-210-3217
js0305.lee@samsung.com
Chang Ho Lee
Samsung Electro-Mechanics
Korea
+82-31-210-3217
changholee@samsung.com
Wangmyong Woo
Samsung Electro-Mechanics
Korea
+82-31-210-3217
wmwoo@samsung.com
Kyutae Lim
Georgia Institute of Technology
USA
+1-404-385-6008
ktlim @ece.gatech.edu
Youngsik Hur
Georgia Institute of Technology
USA
+1-404-385-6008
yshur @ece.gatech.edu
Submission
Slide 2
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Abstract
This contribution presents PHY/MAC protocol specification for CR-enabled
IEEE 802.22 WRAN system.
For PHY layer, this document clearly presents the characteristics of physical
layer, such as system parameters for WRAN, cognitive WRAN transceiver
architecture, OFDMA symbol time structure and parameters, frame structure
for TDD/FDD, subcarrier allocation and pilot pattern, channel coding and
modulation, spectral efficiency and minimum peak throughput, ranging type,
proposed spectrum sensing scheme, and performance analysis, etc.
For MAC layer, it suggests that the existing MAC standard, especially IEEE
802.16 specification, be adopted as a baseline. Some CR-enabled features,
including channel management, are introduced. Furthermore, CR-specific
MAC management messages or information elements are proposed for
modifying the current IEEE 802.16 specification as a baseline.
Submission
Slide 3
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Contents
Part I. PHY Layer
•
•
•
•
•
•
•
•
•
•
•
•
•
WRAN Hierarchy and Deployment Scenario.................................8
Proposed Key Features...................………………..............10
System Parameters for WRAN………………………..……………..11
WRAN Transceiver Architecture……………..............….……….14
OFDMA Parameters ....................................................……...…16
OFDMA Symbol Time Structure ..........................................18
Frame Structure and Parameters for TDD or FDD…………………19
Subchannelization, Preamble, and Pilot Pattern…………………..…23
Channel Coding and Modulation……………………………….….30
Data Rate and Spectral Efficiency………………………...………….36
Minimum Peak Throughput .................................................38
Additional Physical Layer Features…………………….…………39
Design Review………………………………..…………………40
Submission
Slide 4
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Contents
Part II. MAC Layer
•
•
•
•
•
•
•
•
•
•
Overview................…………………………………………………..45
Key Features of MAC………………………….....………………….46
MAC Support of PHY.............................................................. 47
Channel Management ................................................................48
Scanning Operation ...................................................................... 51
Scanning Scenario ........................................................................54
Cooperative Sensing Protocol ........................................................61
BS Coexistence Issue ................................................................... 63
Radio Resource Management………………….…………………….64
CR-Specific Messages & IE’s .........................................................68
Submission
Slide 5
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Contents
Part III. Spectrum Sensing Technologies
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Mission of Spectrum Sensing Block..…………….………………..70
Proposed Spectrum Sensing Technique………......……………….71
Proposed Sensing Scheme ……..................…………..…..72
Advantages…..............………………………………...…………....73
Coarse Spectrum Sensing......…………………..……………..…74
MRSS Schematics………………………….……………....…75
MRSS Simulation Results…………………………………….76
Fine Spectrum Sensing……...………………………………….77
AAC Schematics ....................................................... 78
AAC Implementation ...........................................................79
AAC Simulation Results ....................................................80
Resource for Spectrum Sensing ........................................... 81
Summary of Spectrum Sensing ...............................................82
References…………………………………………………..……….83
Abbreviations………………………………………………………...84
Submission
Slide 6
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
PART 1. PHY Layer
Submission
Slide 7
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
WRAN Hierarchy
Public IP Network
SD
Service Provider IP Network
HA
AAA
ACR
ACR
집
CPE
WRAN
BS
집
집
집
• AAA : Authentication, Authorization and Account Server
• ACR : Access Control Router HA : Home Agent
Submission
Slide 8
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Deployment Scenario
집
집
집
WRAN
Base Station
집
집
집
집
집
Wireless
MIC
집
집
집
집
집
집
집
집
집
집
TV Transmitter
WRAN
Base Station
집
집
집
집
집
집
WRAN
Repeater
집
집
Wireless
MIC
: WRAN Base Station
Typical ~33km
Max. 100km
집
집
집
집
집
집
집
집
집
집
집
집
집
집
집
: CPE
집
집
집
Submission
Slide 9
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
What We Have Proposed ….
Adaptive
OFDMA
FDD/TDD
Known and proven technology
for broadband fixed/mobile wireless access
(e.g., IEEE 802.16d/e – WiBro in Korea)
• Adaptively scalable to spectrum availability
(1,2,3,4,6,7,8MHz bandwidth)
• New frame structure for CR-enabled operation
• Enhanced PHY features
- Cyclic prefix and cyclic postfix
- Adaptive pilot insertion
- Enhanced channel coding, e.g., LDPC
Submission
Slide 10
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
System Parameters: Proposed
Parameters
Specification
Frequency range
54~862 MHz
Service coverage
Typical range 33 km, Maximum 100 km
Bandwidth
1, 2, 3, 4, 5, 6, 7, 8 MHz
Data rate
Spectral Efficiency
Allows for deriving the sub-band
from a single TV channel
• Maximum: 30Mbps
• Minimum: 3Mbps
• Maximum: 0.5 bits/s/Hz
• Minimum: 5 bits/s/Hz
Bandwidth = 6MHz
Bandwidth = 1,2,3,4,5,6,7,8MHz
Modulation
BPSK, QPSK, 16QAM, 64QAM, 256QAM
Transmit power
Multiple Access
FFT Mode
Cyclic Prefix Mode
Cyclic Postfix Mode
Duplex
Default 4W EIRP
Adaptive OFDMA
2048, 4096, 8192
1/4, 1/8, 1/16, 1/32
1/64
TDD or FDD
• TDD: 5 ms or 10 ms
• FDD: 5.103 ms or 10.206 ms
Point-to-Multipoint Network
Frame Length
Network topology
Submission
Remark
Slide 11
Partial bandwidth allocation
To cope with pre-echo signal
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Adaptive OFDMA: Bandwidth Scalability
• Example
Incumbent or
other CR user
f
Unused
Submission
6 MHz
3 MHz
1 MHz
Slide 12
6 MHz
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Adaptive OFDMA: Bandwidth Scalability
• Example
Incumbent or
other CR user
f
6 MHz
Submission
12 MHz
Slide 13
6 MHz
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
WRAN Transceiver Architecture
Directive Antenna
Transmitter
(RF/IF)
PHY
(Baseband)
SW or
Duplexer
Receiver
(RF/IF)
Omni Antenna
MAC
Sensing Receiver
Coarse
“MRSS”
Low Speed
ADC
Fine
“AAC”
* MRSS : Multi-Resolution Spectrum Sensing
** AAC : Analog Autocorrelation
Submission
Slide 14
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
PHY (Baseband) Architecture
P/S
Guard
Insertion
S/P
Guard
Removal
IFFT
Preamble
&
Pilot
Insertion
Subcarrier
Allocator
S/P
FFT
Channel
Estimation
Subcarrier
Deallocator
P/S
Mapper
Puncturer
&
Interleaver
Encoder
Randomizer
Demapper
Deinterleaver
&
Depuncturer
Decoder
Derandomizer
Binary
Data
Channel
AWGN
Recovered
Data
Synchronization
Submission
Slide 15
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
OFDMA Parameters
Mode
2K
4K
8K
FFT Size
2048
4096
8192
Bandwidth
k MHz
(k = 1, 2, 3, 4, 5, 6, 7, 8)
k MHz
(k = 1, 2, 3, 4, 5, 6, 7, 8)
k MHz
(k = 1, 2, 3, 4, 5, 6, 7, 8)
Sampling Factor
8/7
8/7
8/7
No. of Used Subcarriers
(including pilot, but not
DC tones)
208 * k
416 * k
832 * k
Sampling Frequency
64/7 MHz
64/7 MHz
64/7 MHz
Subcarrier Spacing
4.464 kHz(***)
2.232 kHz
1.116 kHz
Occupied Bandwidth
4.464 kHz*208*k
2.232 kHz*416*k
1.116 kHz*832*k
Bandwidth Efficiency(*)
92.93 %
92.93 %
92.93 %
FFT Time
224 us
448 us
896 us
Cyclic Prefix Time(**)
56 us
112 us
224 us
Cyclic Postfix Time
3.5 us
-
-
OFDMA Symbol Time
283.5 us
560 us
1120 us
(*) Bandwidth Efficiency = Subcarrier Spacing * (Number of Used Subcarriers + 1)/BW
(**) It is assumed that cyclic prefix mode and cyclic postfix mode are 1/4 and 1/64, respectively.
(***) Italics indicate an approximated value.
Submission
Slide 16
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Advantages of Adaptive OFDMA Proposal
• Flexible Bandwidth Allocation
– To use the partial bandwidth (1,2,3,4,6,5,7,8MHz) adaptively,
depending on the channel state information (availability)
– To fully utilize available bandwidth under a unified PHY framework
• Single Sampling Frequency
– Sampling frequency is the same, i.e., 64/7MHz, for all FFT modes.
• Constant Subcarrier Spacing
– The subcarrier spacing is constant for all different channel
bandwidths  Robust to the frequency offset
Submission
Slide 17
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
OFDMA Symbol Time Structure
• Type I: Conventional
– 4K & 8K Modes
• Type II: Hybrid
– 2K Mode
Cyclic Prefix
Cyclic Postfix
Cyclic Prefix
Profile D
0
Mode
Cyclic Prefix
Time
2K
56 us
4K
112 us
Relative attenuation (dB)
-5
8K
224 us
-10
-15
-20
-25
-30
-10
-5
0
5
10
15
20
25
30
35
40
45
50
55
60
Excess delay (usec)
< 60us
Submission
Slide 18
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Frame Structure: TDD (1)
Spectrum Sensing
(sensing period = 100ms, quiet period=~5ms)
Submission
Slide 19
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Frame Structure: TDD (2)
• Frame Parameters
Frame Parameters
Frame Length(*)
10 ms
FFT Size
2048
4096
8192
OFDMA Symbol Time(**)
283.5 us
560 us
1120 us
OFDMA Symbols / Frame(**)
34 (DL:UL=23:11)
17 (DL:UL=12:5)
8 (DL:UL=6:2)
TTG Time
321 us
440 us
1000 us
RTG Time
40 us
40 us
40 us
Cell Coverage(***)
< 42.5 km
< 60.6 km
< 145.5 km
(*) It is assumed that frame length is 10 ms
(**) It is dependent on cyclic prefix mode and cyclic postfix mode. Here, it is assumed that cyclic prefix mode and
cyclic postfix mode are 1/4 and 1/64, respectively.
(***) Minimum TTG=round trip delay + tx to rx switching time, Minimum RTG = rx to tx switching time.
It is assumed that it takes 3.3 us for the waveform to reach 1 km and switching time is less than 40 us.
For Typical Range
(33 km)
Submission
Slide 20
For Maximum Range
(100 km)
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Frame Structure: FDD (1)
Submission
Slide 21
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Frame Structure: FDD (2)
• Frame Parameters
Frame Parameters
FFT Size
2048
4096
8192
Frame Length(*)
10.206 ms
10.080 ms
10.080 ms
OFDMA Symbol Time(**)
283.5 us
560 us
1120 us
OFDMA Symbols / Frame(**)
36
18
9
(*) It is assumed that frame length is about 10 ms
(**) It is dependent on cyclic prefix mode and cyclic postfix mode.
Here, it is assumed that cyclic prefix is 1/4 and cyclic postfix mode is 1/64 for 2K mode only.
Submission
Slide 22
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Subchannelization (1)
Subcarrier Allocation
Distributed
Subcarrier permutation
Adjacent
Subcarrier Permutation
Scattered type
Band type
BIN
Band #1
Band #1
BIN
Band #2
Band #3
Band #2
Band #4
…
Band #3
Band #5
…
User 0
User 1
…
…
User 0
User 2
User 1
Band #24
User 2
User 3
Band #48
Symbol
Submission
Slide 23
Symbol
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Subchannelization (2)
• Type of subchannelization is determined by channel quality information
Adjacent
Subcarrier Permutation
Distributed
Subcarrier permutation
• Each subchannel consists of a
group of adjacent subcarriers
• Bands in good state are selected
for data transmission
• Multiuser diversity
• Require more feedback
information than distributed
subcarrier allocation type
Submission
• Each subchannel consists of
distributed subcarriers within an
OFDM symbol
• Only the average CINR over all
subcarriers is required
• For users with high frequency
selectivity or far distant users
Slide 24
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Subchannelization (3)
• Band-Type Adjacent Subcarrier Allocation
– To achieve the multi-user diversity gain
– Multiple bins allocated to each user
(Bin denotes a group of adjacent subcarriers).
BIN
Band #1
Band #2
Band #3
…
…
User 0
User 1
Band #24
User 2
Symbol
Submission
Slide 25
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Subchannelization (4)
• Scattered-Type Adjacent Subcarrier Allocation
– To achieve the multi-user diversity gain
– Only one bin allocated to each user
Band #1
BIN
Band #2
Band #3
Band #4
Band #5
…
User 0
…
User 1
User 2
User 3
Band #48
Symbol
Submission
Slide 26
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Subchannelization (5)
• Distributed Subcarrier Allocation
– Subcarriers are pseudo-randomly selected for frequency diversity
Number of used subcarriers
Subcarriers
Pilot subcarriers
...
Data subcarriers
...
Groups
G0
G1
G2
...
GN
...
Subchannels
Submission
Slide 27
S0
S1
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
SM
November 2005
doc.: IEEE 802.22-05/0109r1
Preamble
• Preamble has the repetition pattern in the time domain:
– Time synchronization
– Frequency synchronization
– Cell ID detection
– Channel estimation
• Preamble is modulated using a boosted BPSK modulation
Submission
Slide 28
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Pilot Pattern
• Pilot pattern is varied with channel condition:
- Adaptively rotated pilot pattern
- Channel estimation by preamble or pilot, depending on power boosting
• Pilot subcarriers are modulated using a boosted BPSK
modulation
Preamble
OFDMA Symbol Direction
Data
Subcarrier
Subcarrier Direction
Direction
Pilot
Subcarrier
Period(variable)
Pilot
Subcarrier
Period(variable)
Pilot Symbol
Period(variable)
Pilot Symbol
Period(variable)
Pilot Symbol
Period(variable)
Boosted Pilot
Submission
Slide 29
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Channel Coding (1)
• Coding Scheme
–
–
–
–
LDPC Code
Convolutional Turbo Code
Convolutional Code
Concatenated Code : BCH+LDPC (CC or CTC)
• Code Rates
– For LDPC, R = 1/2, 2/3, 3/4, 5/6, 7/8 can be supported
– For CTC, R = 1/3, 1/2, 2/3, 3/4, 5/6, 7/8 can be supported
– For CC, R = 1/2, 2/3, 3/4, 5/6, 7/8 can be supported
Submission
Slide 30
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Channel Coding (2)
• LDPC Encoder
• CTC Encoder
– Duo-binary CTC
output
A
A
B
B
1
CTC
Interleaver
Constituent
Encoder
2
C1
Y1W1
C2
Y2W2
ST
p1
Information bits
ST
ET-1
A
 1
T-1
B
p2
switch
Systematic part
C
H matrix
A
S1
S2
S3
n  m
m  p
A
B
T  I
D
E
p
B
p
p
Parity part
Y
W
C
Submission
Slide 31
m  p
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Channel Coding (3)
• CTC Decoder
Le2 (u )
2

2

yk

yp
2 1
MAP
INT
decoder L (u )
e1
2
2
S/P 
2
ys
MAP
decoder
INT
2

2
DEINT
û k
y 2p
• LDPC Decoder
memQ
_even
B
B
memR
_even
A
memQ
_odd
B
B
memR
_odd
A: Bit_to_Check block ; memQ(even,odd):implement a pair of message buffers alternating between R/W
B: Check_to_Bit block ; memR(even,odd): implement a pair of message buffers alternating between R/W
Submission
Slide 32
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Channel Coding (4)
• Performance Comparison: CTC vs. LDPC
- Code rate of 1/2 over WRAN channel model C
0
10
16QAM
QPSK
64QAM
256QAM
-2
10
Blue1
-4
10
BER
Blue2
-6
10
WRAN
Channel
profile C
Multi-path
Fading
-8
6-Paths
Carrier=617MHz
Dopper=0.10
200 Frames
-10
Blue1:
Blue2:
Red1:
Red2:
10
10
Submission
0
Red1
Red2
1/2Turbo message 728 bits
1/2Turbo message 1456 bits
1/2LDPC H size 728*1456
1/2LDPC H size 1456*2912
5
10
15
Eb/No(dB)
Slide 33
20
25
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Channel Coding (5)
• Performance Comparison: CTC vs. LDPC
- Code rate of 2/3 over WRAN channel model C
0
10
QPSK
16QAM
64QAM
256QAM
-1
10
-2
10
Blue1
-3
BER
10
-4
10
-5
10
-6
10
-7
10
Submission
Blue2
Multi-path fading
WRAN Channel profile C
6-Paths
Carrier=617MHz
Dopper=0.10
200 Frames
Red1
Red2
Blue1:2/3Turbo message bits 728
Blue2:2/3Turbo message bits 1456
Red1:2/3 LDPC H size 364*1092
Red2:2/3 LDPC H size 728*2184
5
10
15
Eb/No(dB)
Slide 34
20
25
30
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Modulation
Subcarrier Type
Modulation
Preamble/Pilot
BPSK
Control Channel
BPSK or QPSK
DL
Spread-BPSK (optional), QPSK, 16QAM,
64QAM, 256QAM
UL
QPSK, 16QAM, 64QAM
Traffic
Submission
Slide 35
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Data Rate
•
•
•
•
•
Bandwidth = 6MHz
Pilots and quiet periods are NOT accounted
FFT size = 2048
Cyclic prefix mode = 1/4
cyclic postfix mode = 1/64
Code Rate
Unit: Mbps
7/8
5/6
3/4
2/3
1/2
256QAM
30.8
29.37
26.4
23.43
17.6
64QAM
23.1
22.0
19.8
17.6
13.2
16QAM
15.4
14.63
13.2
11.77
8.8
QPSK
7.7
7.37
6.6
5.83
4.4
Modulation
Data Rate = No. of used subcarriers * code rate * no. of bits per modulation symbol/OFDM symbol time
Submission
Slide 36
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Spectral Efficiency
•
•
•
•
•
Bandwidth = 1,2,3,4,5,6,7,8 MHz
Pilots and quiet periods are NOT accounted
FFT size = 2048
Cyclic prefix mode = 1/4
cyclic postfix mode = 1/64
Code Rate
Unit : bps/Hz
7/8
5/6
3/4
2/3
1/2
256QAM
5.16
4.89
4.40
3.91
2.93
64QAM
3.85
3.67
3.30
2.93
2.20
16QAM
2.57
2.45
2.20
1.96
1.47
QPSK
1.28
1.22
1.10
0.98
0.73
Modulation
Spectral Efficiency = No. of used subcarrier*code rate*no. of bits per modulation symbol/OFDM symbol time/BW
The proposal meets the spectral efficiency in the SRD:
min 0.5 bps/Hz, max 5 bps/Hz or better
Submission
Slide 37
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Minimum Peak Throughput
•
•
•
•
•
•
Bandwidth = 6MHz
Pilots and quiet periods are NOT accounted
FFT size = 2048
Cyclic prefix mode = 1/4
cyclic postfix mode = 1/64
No. of CPE’s = 512 CPE’s/oversubscription ratio 50 ~ 11 CPE’s
Unit : Mbps
Code Rate
Modulation
256QAM
64QAM
16QAM
QPSK
7/8
5/6
3/4
2/3
1/2
2.80
2.10
1.40
0.70
2.67
2.00
1.33
0.67
2.40
1.80
1.20
0.60
2.13
1.60
1.07
0.53
1.60
1.20
0.80
0.40
Min. Peak Throughput = No. of used subcarriers*code rate*no. of bits per modulation symbol/OFDM symbol time/no. of CPE’s
 The proposal meets the minimum peak throughput in the SRD:
1.5 Mbps (DL) and 384 kbps (UL)
Submission
Slide 38
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Additional Physical Layer Features
• Stationary Beam Forming with Dynamic Channel
Allocation
• Transmit/Receive Diversity
• Robust DL Channel for Public Safety using SpreadBPSK
• Efficient Sleep Mode Operation
Submission
Slide 39
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Design Review: PHY Layer
 Checking the functional requirements for IEEE 802.22 WRAN
WRAN Functional
Requirements
Our Proposal
Minimum
Data Rate
DL: 1.5 Mbps/subscriber DL:2.8 Mbps/subscriber
UL: 384 kbps/subscriber UL:400 kbps/subscriber
Service
Coverage
Typical: 33 km
Maximum: 100 km
Typical: 42.5 km(2K mode), 60.6 km(4K mode)
Maximum: 145.5km(8K mode) (*)
Spectral
Efficiency
Minimum: 0.5 bits/s/Hz
Maximum: 5 bits/s/Hz
Minimum: 0.73 bits/s/Hz
Maximum: 5.16 bits/s/Hz
Maximum Pre-echo: 3 us
Excess Delay Post-echo: 60 us
Pre-echo: 3.5 us (2K mode)
Post-echo: 112 us(4K mode), 224 us (8K mode)
(*) It is calculated from the point of view of TTG time, not from link budget.
Submission
Slide 40
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
PART 2. MAC Layer
Submission
Slide 41
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Can you believe that we do not need any
new MAC protocol for CR system?
Whether you believe or not, the existing MAC protocol
can be employed in CR system as it is!!!
It can be done by introducing only one new message
with some modification in the existing control signal
First of all, you have to understand what
makes CR system so complicated!
Submission
Slide 42
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
What Makes CR System so Complicated?
• CASE 1: IU detected by both BS and CPE
IU(Fy)
TV
 Immediately rendezvous
CPE(Fx,Fy)  CPE(Fx,,Fz]
BS(Fx,Fy)  BS(Fx,Fz)
집
CPE(Fx,Fy)
BS(Fx,Fy)
• CASE 2: What if IU can be detected by either BS or CPE only?
TV
4 different
cases
Interference detected in
IU = U/L
IU = D/L
Case (i)
Case (ii)
Case (iii)
Case (iv)
집
IU
BS
detected by CPE
Submission
Slide 43
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
What is Our Idea, then?
Key Idea: Implicit Signal-based Cooperative Sensing
Everything looks fine,
so let me keep it up….
집
I found IU just had appeared,
so I now have to search for new band….
By the way, do he know about that?
Submission
Slide 44
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Overview
• Rendezvous Procedure for Band Switching
IU = UL or DL
Detected in Fx?
IU = UL or DL
Detected in Fx?
No
Implicit/Explicit
Signaling
Yes
Band Change:
Fx  Fy
Acknowledged
from CPE?
Searching for Fy
Yes
Rendezvous?
Yes
Initialized in Fy?
No
No
Submission
Yes
Slide 45
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Key Features of MAC
• Minimal changes in the IEEE 802.16d MAC specification
- To adopt the existing MAC specification with additional CR-enabled
MAC features
• Channel management
- To define CR-specific channel sets
• Scanning operation
- To support cooperative (distributed) sensing with implicit signaling
 No control channel required!
• Radio resource management
- Channel grouping for MAP overhead reduction in the multi-FA system
- Active set update to maximize the average system throughput
Submission
Slide 46
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
MAC Support of PHY
• Frame Structure :TDD
100 ms superframe
10 (5) ms
Frame #0
Frame #1
-CQI channel region
- UL_MAP allocation
Preamble
region
RTG
UL Bursts #1
DL Bursts #3
- DL burst allocation
- UL burst allocation
UL
Frame # 9
(#19)
DL Bursts #2
DLMAP
ULMAP
Frame #8
(#18)
UL Bursts #0
FCH
DL Bursts#1
- BR/Periodic
ranging
Frame #3
TTG
DL
- Frame control
- CH grouping /
matching
- Initial ranging
region
Frame #2
UL Bursts #2
UL Control ( ACK,..)
DL Bursts #4
Ranging
Submission
Slide 47
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Channel Management (1)
• Channel Set: Definitions
-
Active set 1: a set of used channels for a certain CPE
Active set 2: a set of used channels for a certain BS
Candidate set: a set of five clean channels available for a certain CPE or BS
Occupied set: a set of occupied channels by incumbent user which a certain CPE finds
Disallowed Set: a set of channels whose access are not allowed by regulation
Null set : a set of channels that are not classified as one of above five sets
* Note: The allowed set is defined by union of candidate set and null set depending on
channel’s SIR level
• Channel Set Maintenance
- Each BS maintains five channel sets: Active 1, Active 2, Occupied, Candidate, Null
- Each CPE maintains four channel sets: Active 1, Active 2, Candidate, Occupied
- Each set is updated in every interval of quiet period (either at a fixed interval or
aperiodic interval) and notified in DCD.
Submission
Slide 48
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Channel Management (2)
• Transition diagram for channel set
 The channel becomes useless as incumbent service
appears.
 Incumbent service releases the channel, but
classified as a member of candidate set as quality
goes above a given threshold.
 Incumbent service releases the channel, but
classified as a member of null set as quality goes
below a given threshold.
 The channel is classified as a member of candidate
set as quality goes above a given threshold.
 The channel becomes active as quality goes above
a given threshold.
 The channel is classified as a member of null set
as quality goes below a given threshold.
 The channel is released due to the finish of its usage.
Submission
Slide 49
Null Set
6
6
3
4
1
Active Set
5
7
1
1
Candidate Set
Occupied Set
2
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Channel Management (3)
• Modified DCD
– To update the channel sets in a broadcast message
Field
Note
………
Number of DL_Channels
for (i=1; Number of DL Channels) {
To specify all channels that CR-BS can use
Channel ID }
Number of active set 2 channels
for (i=1; Number of active set 2 channels) {
To specify the channel IDs of active set 2
Channel ID}
Number of occupied set channels
for (i=1; Number of occupied set channels) {
To specify occupied set channel IDs
Channel ID}
Number of CPEs
for (i=1; Number of CPEs) {
(CPE_ID, channel ID)
}
To specify the channel IDs of the candidate
set for individual CPE
………
Submission
Slide 50
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Scanning Operation: Overview (1)
• Rendezvous Procedure for Band Switching
IU = UL or DL
Detected in Fx?
IU = UL or DL
Detected in Fx?
No
Implicit/Explicit
Signaling
Yes
Band Change:
Fx  Fy
Acknowledged
from CPE?
Searching for Fy
Yes
Rendezvous?
Yes
Initialized in Fy?
No
No
Submission
Yes
Slide 51
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Scanning Operation: Overview (2)
• Network Entry & Initialization
Scan for
Downlink Channel
CPE Authorization &
Key Exchange
Downlink Sy nch.
Es tablis hed
CPE Authorization
Complete
Obtain Uplink
Parameters
Regis ter
with BS
Es tablis h
Time of Day
Normal
Uplink Parameters
Acquired
Regis tration
Complete
Time of Day
Es tablis hed
Traffic
connectio
n
request
Ranging & Automatic
Adjus tments
Es tablis h I P
Connectiv ity
Ranging & Automatic
Adjus tments Complete
IP
Complete
Negotiate Bas ic
Capabiliities
Update Channel
Set Information
Es tablis h Prov is ioned
Connections
Bas ic Capabilities
Negotiated
Channel Set
Updated
Operational
Pow er on
System access
(Netw ork entry)
Initialization
Traffic
connection
setup
DSA
User data
transm ission
Connection
established
Submission
Slide 52
Trans fer Operational
Parameters
Trans fer
Complete
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Scanning Operation: Overview (3)
• Normal Operation
BS
CPE
QP
Fx:MAP
QP
Superframe
CR-SCAN-RSP
Fx:MAP
..
.
- Message field
..
.
QP
Fx:MAP
CR-SCAN-RSP
• Scan response Message: CR-SCAN-RSP
- Every quiet period, CPE must respond
with their scanning results.
- The scanning results include C/I
measurement, spectrum set management
parameters, etc.
QP
Field
Management message type
= xxx
Note
Number of channels for
which CPE performs
scanning
Number of
channels_to_scan
for (i=1; Number of
channels_to_scan) {
Channel ID
Scanning method refers to
the channel measurement
types, e.g., CIR and IU
detection.
Scanning method
Scanning result }
Submission
Slide 53
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Scanning Scenario: IU = D/L - BS
• Normal Operation
QP
Fx:MAP
BS
TV
Transmitter
QP
QP
D
집
Superframe
CR-SCAN-RSP
Fx:MAP
CPE
QP
Fx:Null
Time-out
IU  D/L
CPE
Fx:Null
집
집
..
.
Fx:Null
집
..
.
WRAN
Base Station
집
집
..
.
Fz:MAP
Fz:MAP
..
.
집
QP
QP
집
Fx:MAP
QP
CPE
집
CR-SCAN-RSP
Submission
Slide 54
Fz:MAP
CR-SCAN-RSP
Fz:MAP
QP
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
Initialization
BS
• Implicit Band Switching
November 2005
doc.: IEEE 802.22-05/0109r1
Scanning Scenario: IU = D/L - CPE (1)
• Normal Operation
Fx:MAP
TV
Transmitter
QP
Fx:MAP
집
Fx:MAP
Time-out
Superframe
D
QP
QP
CR-SCAN-RSP
집
집
..
.
CPE
Fx:MAP[SCAN-REQ]
Fx:MAP[SCAN-REQ]
집
..
.
WRAN
Base Station
집
집
Fz:MAP
..
.
Fz:MAP
집
QP
..
.
집
Fx:MAP
QP
CPE
집
QP
Fz:MAP
CR-SCAN-RSP
QP
CR-SCAN-RSP
Fz:MAP
Submission
Slide 55
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
Time-out (Ranging)
QP
BS
IU  D/L
CPE
Initialization
BS
• Implicit Band Switching
November 2005
doc.: IEEE 802.22-05/0109r1
Scanning Scenario: IU = D/L - CPE (2)
• Implicit Band Switching
BS
CPE
Time-out
Fx:MAP[SCAN-REQ]
Fx:MAP[SCAN-REQ]
Fz:MAP
..
.
Fz:MAP
QP
Fz:MAP
CR-SCAN-RSP
Fz:MAP
..
.
Initialization
QP
Fx:MAP
Time-out (Ranging)
D
QP
• CR-SCAN-REQ_IE in UL-MAP
- New information element is included
in the UL-MAP for fast implicit signaling
(short implicit scanning)
-
UL-MAP Information Element
Field
Extended UIUC
Broadcasting/unicasting
Duration
Quiet period length
CID
Broadcasting/Primary CID
Number of
channels_to_scan
Number of channels for which
CPE performs scanning
for (i=1; Number of
channels_to_scan) {
Channel ID
QP
}
Scanning method
Data region
Submission
Note
Slide 56
Scanning method refers to
the channel measurement
type, e.g., CIR.
Resource allocation for Scan
response (PHY dependent)
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Scanning Scenario: IU = U/L - BS (1)
• Implicit Band Switching
• Normal Operation
BS
BS
CPE
CPE
TV
Transmitter
QP
Fx:MAP
QP
QP
U
Fx:MAP
QP
집
집
Fx:MAP[SCAN-REQ]
집
..
.
..
.
집
WRAN
Base Station
집
집
..
.
Fy:MAP
Fy:MAP
..
.
Fy:MAP
QP
집
QP
Fx:MAP
QP
QP
집
CPE
집
CR-SCAN-RSP
Submission
CR-SCAN-RSP
Slide 57
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
Initialization
Superframe
Fx:MAP
Time-out
Fx:MAP[SCAN-REQ]
CR-SCAN-RSP
November 2005
doc.: IEEE 802.22-05/0109r1
Scanning Scenario: IU = U/L - BS (2)
• Explicit Band Switching
• Band Change Request Message:
CR-CHANGE-REQ
CPE
QP
U
..
.
Fx:MAP[SCAN-REQ]
Fy:MAP
..
.
Fy:MAP
QP
CR-SCAN-RSP
An explicit message to direct a
corresponding band to move to new band
- Message field
QP
Fx:CR-CHANGE-REQ
Fy:MAP
QP
-
Initialization
BS
Field
Note
Management message
type = xxx
Current channel ID
The band (TDD: one band,
FDD: band pair) in which IU
has appeared.
New Channel ID
The band (TDD: one band ,
FDD: band pair) to which CR
system is moved.
Remaining channel
move time
Reason code
Submission
Slide 58
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Scanning Scenario: IU = U/L - CPE
• Implicit Band Switching
• Normal Operation
BS
BS
CPE
TV
Transmitter
QP
Fx:MAP
CPE
U
QP
QP
Fx:MAP
QP
Time-out
집
Fx:MAP
집
Fx:MAP[SCAN-REQ]
Fx:MAP[SCAN-REQ]
집
..
.
..
.
집
WRAN
Base Station
집
Fz:MAP
..
.
집
Fz:MAP
..
.
집
QP
Fx:MAP
QP
QP
집
CPE
집
CR-SCAN-RSP
Submission
Fz:MAP
QP
CR-SCAN-RSP
Fz:MAP
Slide 59
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
Initialization
Superframe
CR-SCAN-RSP
November 2005
doc.: IEEE 802.22-05/0109r1
Scanning Scenario: IU = U/L - CPE (3)
• Long periodic scanning vs. short implicit scanning
- Short implicit scanning
- Long periodic scanning
BS
BS
CPE
IU  D/L
Fx:MAP
U
QP
TV
Transmitter
U
QP
CPE
QP
Fx:MAP
QP
Fx:MAP
Time-out
집
Fx:MAP[SCAN-REQ]
Fx:MAP[SCAN-REQ]
집
..
.
..
.
집
WRAN
Base Station
집
Fz:MAP
..
.
집
Fz:MAP
QP
집
Fx:MAP
QP
QP
집
CPE
집
Fz:MAP
QP
CR-SCAN-RSP
Fz:MAP
Fx:MAP
Submission
..
.
Slide 60
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
Initialization
Time-out
Superframe
집
November 2005
doc.: IEEE 802.22-05/0109r1
Cooperative Sensing Protocol: BS
Periodic sensing
report start
Received sensing
result
IU detected by
BS in D/L
IU detected by
BS in U/L
No IU detected
by BS
Waiting for CRSCAN-REP
Start timer T1
Start timer T4
Waiting for CRSCAN-REP
Or periodic ranging
Start timer T3
Start timer T2
Time out T4
Time out T1
Transmit CRSCAN-REQ_IE
Received
CR-SCAN-RSP
Time out T2
IU detected by
BS in U/L
Received periodic
ranging
Time out T3
Time out T4
Rendezvous
End
Transmit CRSCAN-REQ_IE
Rendezvous
Submission
Rendezvous
IU detected by
BS in D/L
Rendezvous
Slide 61
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Cooperative Sensing Protocol: CPE
Periodic sensing
report start
Sensing result
Is received
IU detected by
CPE in U/L
Rendezvous
No IU detected
by CPE
IU detected by
CPE in D/L
Waiting UL-MAP
for
CR_SCAN_REP
Start timer T3
Start timer T5
Periodic
ranging
Time out T3
UL MAP received
Time out T5
CR-SCAN-REQ_IE
received
Rendezvous
Transmit CRSCAN-RSP
End
Submission
IU detected by
CPE In D/L
Rendezvous
Slide 62
IU detected by
CPE In U/L
Rendezvous
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
BS Coexistence Issue
• BS coexistence problem may not be typical, because
– BS coverage is typically large.
– Not many BS’s are required when CR is deployed in rural area.
• BS-to-BS wireless communication needs much cost
– BS needs exactly two times transmit power than normal
communication (BS to CPE).
– Needs special MAC protocol or special entity (e.g., relay CPE) for
medium access coordinator between BS and BS.
– The doubled transmit power is more likely to worsen the hidden IU
problem.
– BS-to-BS frame synchronization is essential.
 Wired based communication is more preferable !!
Submission
Slide 63
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Radio Resource Management
for Multi-FA System (1)
• Multi-FA Resource Allocation
UL
DL
1
2
3
1’
N
2’
3’
N’
6MHz
MAP
DL
Burst#4
Burst#5
Burst#2
DL
Burst #3
time
Burst #1
MAP
Multi-FA Resource Allocation:
FA-1 MAP + FA-3 MAP
Burst #6
BS
1’
3’
1
3
MAP overhead for
Specifying multi-FA
allocation
3’
3
CPE 1
Submission
1’
1
Slide 64
3’
1’
3
1
CPE 3
CPE 2
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Radio Resource Management
for Multi-FA System (2)
• FA Grouping and Matching
DL
1
2
UL
3
1’
N
2’
3’
N’
6MHz
FA-1 MAP
Burst#4
Multi-FA Resource Allocation by FA Grouping:
FA-1 MAP + FA-3 MAP
DL
Burst#5
Burst#2
DL
Burst #3
time
Burst #1
FA-3 MAP
Burst #6
FA
Matching
BS
FA
Matching
1’
3’
1
3’
CPE 1
3
3
FA Matching:
To select (UL and
DL) active set 1 for
individual CPE
Submission
FA Grouping:
To select a group of
CPE’s that are assigned
to the same FA
Slide 65
CPE 3
CPE 2
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Radio Resource Management
for Multi-FA System (3)
• Active Set Update & FA Regrouping
BS
3’
3
3’
3
QP
CR-SCAN-RSP
F3:MAP[SCAN-REQ]
CR-SCAN-RSP[FA1]
CPE 3
CPE 2
Fx:DL-MAPPrefix[CHG=1]
CPE 2: Active
Set 1 changed
(FA3FA1)
BS
1’
1
CPE 1
1’
1
3’
3
F1:MAP
..
..
F1:MAP
..
..
Initialization
1’
1
CPE 1
CPE 2
BS
F1:MAP
CPE 3
FA Regrouping
Submission
CPE 2
Slide 66
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Radio Resource Management
for Multi-FA System (4)
• CR-GROUP-CHG Information Element
CPE 2
BS
- DL-MAP Information Element
QP
CR-SCAN-RSP
F3:MAP[SCAN-REQ]
CR-SCAN-RSP[FA1]
Fx:CR-GROUP-CHG
..
..
F1:MAP
..
..
Initialization
F1:MAP
Field
Extended DIUC
Number of CPEs_to_update
for (i=1; Number of
CPEs_to_update) {
CPE CID
Group ID
DL channel ID
UL channel ID
}
Note
Primary CID
New group ID
New group DL
New group UL
F1:MAP
Submission
Slide 67
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
CR-Specific Messages & IE’s
Type
New
Messages
Message or IE
CR-SCAN-RSP
Usage
Note
Scan response
message
CR-CHANGE-REQ
Band switch
request
Optional
CR-SCAN-REQ
Scan request
Information
Element
To be included in
UL-MAP
CR-GROUP-CHG
Group change To be included in
DL-MAP
Modified
Message
DCD[spectrum
set]
Spectrum set
information
Submission
Slide 68
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
PART 3. Spectrum Sensing Technologies
Submission
Slide 69
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Mission of Spectrum Sensing Block
•
•
•
•
•
•
Provide spectrum occupancy information to MAC
Identify type of incoming signal
Fast tracking time to improve data throughput
Flexible resolution for adaptive and scaling searching
Simple computation for low power
Easy implementation for low cost
Submission
Slide 70
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Proposed Spectrum Sensing Technique
• Features
–
–
–
–
Sensing block is separated from transceiver
Multiple sensing strategy : Coarse and Fine
Sensing while in communication and not in communication
Critical computation is performed at analog domain
• Proposed Sensing Technique
– Multi-Resolution Spectrum Sensing (MRSS) : Coarse sensing, detect
existence of signal
– Analog Autocorrelation (AAC) : Fine sensing, categorize the signal type
Submission
Slide 71
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Proposed Sensing Scheme
Directive Antenna
Transmitter
(RF/IF)
PHY
(Baseband)
SW or
Duplexer
Receiver
(RF/IF)
Omni Antenna
MAC
Sensing Receiver
Coarse
“MRSS”
Low Speed
ADC
Fine
“AAC”
Submission
Slide 72
Spectrum
Recognition
Algorithm
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Advantages
• Sensing block is separated from transceiver
– The sensing block is separated from PHY and controlled by MAC
– Sensing can be performed without waking-up PHY
– Sensing is performed, while not in using, as well as in using
• Multiple sensing strategy
– Two step sensing : The coarse sensing for spectrum occupancy and fine sensing for
identifying incoming signal
– Reduce the false detect rate
• Wavelet based sensing architecture
– Flexibility in sensing resolution and speed
– RF Filter is not required on the sensing path
– Relaxing RF components constraint, linearity and noise
• Critical computation is performed at analog domain
–
–
–
–
Submission
No significant computation, such as FFT nor Correlation, in the baseband
Faster recognition time
Drastically reduce power consumption
Require very low speed/low resolution ADC
Slide 73
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Coarse Spectrum Sensing
Multi-Resolution Spectrum Sensing (MRSS)
• MRSS detect spectral components of incoming signal by the Fourier
Transform.
• Fourier Transform is performed in analog domain.
• MRSS may utilize wavelet transforms as the basis function of the
Fourier Transform.
• Bandwidth, resolution and center frequency can be controlled by
wavelet function
Submission
Slide 74
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
MRSS Schematics
y (t )  x(t )  w(t )
T
  x( ) w(t   )d
0
X
x(t)
Driver Amp

z(t)
y(t)
ADC
CLK#2
w(t)
CLK#1
v(t)*fLO(t)
Timing
Clock
MAC
Wavelet
Generator
Submission
Slide 75
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
MRSS Simulation Results (example)
40
-50
20
-60
0
-70
-20
-80
PSD (dB)
Power Spectrum Magnitude (dB)
Wireless Microphone (FM) Signal
-40
-90
-60
-100
-80
-110
-100
0
0.2
0.4
0.6
0.8
1
1.2
Frequency
1.4
1.6
1.8
2
x 10
The spectrum of the wireless
microphone signal
Submission
-120
6
0
0.2
0.4
0.6
0.8
1
1.2
Frequency (Hz)
1.4
1.6
1.8
2
x 10
6
The corresponding signal spectrum
detected with the MRSS technique
Slide 76
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Fine Spectrum Sensing
Analog Autocorrelation (AAC)
• Recognize the periodic features of the input signals
unique for each modulation format or frame structure
• Auto correlation is done at the analog domain
• AAC can recognize the following input signals :
• IS-95, WCDMA, EDGE, GSM, Wi-Fi, Wi-MAX,
Zigbee, Bluetooth, Digital TV (ATSC, DVB), and
like
Submission
Slide 77
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
AAC Schematics
Sensing Antenna
x(t)
Multiplication
Integrate
FIR
Low
Speed
ADC
Delay Td
x(t-Td))
Decision
Making
Submission
Slide 78
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
AAC Implementation
• An input RF signal x(t) is divided and delayed by a certain
delay value Td.
• The correlation between the original input signal x(t) and
the delayed signal x(t- Td) is performed at analog domain.
• If the resulting integrator output shows sharp pulse, that Td
indicates the feature of the incoming signal.
• Since AAC is performed at analog domain, low speed
ADC is sufficient.
Submission
Slide 79
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
AAC Simulation Results (Example)
OFDM Signal
(3)
(1)
(2)
(3)
(1)
(2)
Multiplier Output Waveform
Submission
FIR Output Waveform
Slide 80
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Resource for Spectrum Sensing (Example)
• Freq. for searching : 50-850MHz (800MHz span)
• Wf(3dB BW of Gaussian frequency window) : 8MHz
• Wt(3dB Time window size) = 0.0625 usec
• Applied time pulse window = Wt x 3 =0.1875
• No. of freq. point : 100 points
• No. Freq. sweeping : 10 times (for signal processing)
% ADC sampling frequency can be adjusted to meet total sweeping time.
Optimized for Low power
Optimized for Speed
•Sampling freq. = 5.33Ms/s
•Time for one sweep = 18.75usec
•Time for 10 sweep = 0.1875msec
•Resolution = 6 bit, dynamic range= 36 dB
•Additional SNR improvement = 10dB
Submission
•Sampling freq. = 500 Ks/s
•Time for one sweep = 0.2 msec
•Time for 10 sweeps = 2 msec
•Resolution = 6 bit, dynamic range= 36 dB
•Additional SNR improvement = 10dB
Slide 81
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Summary of Spectrum Sensing Block
Specification
ADC resolution
6 bit (MRSS)
1-3 bit (AAC)
ADC sampling time
>5M sample/sec (MRSS)
>120 k sample/sec (AAC)
Sensing time
< 1 m sec (while in communication)
< 4 m sec (while not in communication)
Sensing threshold
<-110 dB
Baseband processing in
PHY
No significant computation, such as FFT nor
Convolution, is required at the baseband.
Baseband processing in
MAC
Noise reduction, harmonic suppressions
Submission
Slide 82
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
References
[1] IEEE Standard for Local and Metropolitan Area Network-Part 16: Air
Interface for Fixed Broadband Wireless Access Systems, IEEE Std.
802.16-2004
[2] Digital Video Broadcasting(DVB); Framing Structure, Channel
Coding and Modulation for Digital Terrestrial Television, ETSI EN
300 744 V1.5.1(2004-06)
[3] Transmission System for Digital Terrestrial Television Broadcasting,
ARIB STD-B31 V1.5
[4] IEEE Standard for Local and Metropolitan Area Networks-Part 11:
Wireless LAN Medium Access Control(MAC) and Physical
Layer(PHY) Specifications, IEEE Std 802.11a-1999
[5] IEEE Std 802.11h-2003 (Amendment to IEEE Std 802.11, 1999 Edn.
(Reaff 2003)) Publication Date: 2003
Submission
Slide 83
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT
November 2005
doc.: IEEE 802.22-05/0109r1
Abbreviations
AAC
BE
BR
BS
CC
CID
CoS
CPE
CQI
CR
CRC
CTC
DCD
DFS
DL
DSA
EC
FA
FCH
FDD
HT
IE
Submission
Analog AutoCorrelation
Best Effort
Bandwidth Request
Base Station
Convolutional Code
Connection IDentifier
Class of Service
Consumer Premise Equipment
Channel Quality Indicator
Cognitive Radio
Cyclic Redundancy Check
Convolutional Turbo Code
Downlink Channel Descriptor
Dynamic Frequency Selection
Downlink
Dynamic Service Addition
Encryption Control
Frequency Allocation
Frame Control Header
Frequency Division Duplexing
Header Type
Information Element
IU
LDPC
MAC
MRSS
nrtPS
OFDMA
PDU
PHSI
PHY
PU
QoS
RRM
RTG
rtPS
SDU
TDD
TTG
UCD
UGS
UL
WRAN
Slide 84
Incumbent User
Low Density Perity Check
Medium Access Control
Multi-Resolution Spectrum Sensing
non real time Polling Service
Orthogonal Frequency Division Multiple Access
Protocol Data Unit
Packet Header Suppression Indicator
PHYsical layer
Primary User
Quality of Service
Radio Resource Management
Receive/Transmit Transtion Gap
real time Polling Service
Service Data Unit
Time Division Duplexing
Transmit/Receive Transition Gap
Uplink Channel Descriptor
Unsolicited Grant Service
Uplink
Wireless Regional Area Network
C.J.Kim/ETRI, H.S.Kim/SEM, J.Laskar/GT