March 2 006 Huawe i, Ne xtWav Slide 1 doc.: IEEE 802.22-06/0030r0 Submission IEEE 802.22 WRAN Standard PHY/MAC Proposal IEEE P802.22 Wireless RANs Date: 2006-03-06 N am e C om pany A ddress Phone em ail Soo-Y oung Chang H uaw ei 6000 JStreet, D ept EEE, Sacram ento, CA 95819-6019 1-916 278 6568 sychang@ ecs.csus.edu W endong H u STM icroelectronics 1060 E. Brokaw Rd. San Jose, CA 95131 1-408-467-8410 [email protected]Ram on K halona N extW ave 2075 LasPalm asD r Carlsbad, CA 92009 1-760-710-2063 rkhalona@ nextw avetel .com EliSofer Runcom 2 H achom a St. Rishon Lezion, Israel +972 544 997 996 elisofer@ runcom .co.il Authors: 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
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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 [email protected].>
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 2
doc.: IEEE 802.22-06/0030r0
Submission
Co-Authors
Name Company Address Phone email
Paul Piggin Cygnus
Jianwei Zhang Huawei
No. 98, Lane 91, Eshan Road, Pudong, Pudong Lujiazui Software Park,
In this presentation, we provide a technical overview of a full proposal for the Physical
(PHY) layer and the Medium Access Control (MAC) layer of the IEEE 802.22
Wireless Regional Networks (WRAN) Standard.
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 4
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Submission
PHY proposalPHY proposal
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 5
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Submission
What we have Proposed
Meeting Incumbents and SP`s Expectations
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 6
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Submission
OFDMA (Scalable FFT, 2k, 1k, 512) on both Uplink and Downlink enabling a highly flexible and dynamic network resource management, handling of multipath, efficient cellular rollout, efficient multiple access operation and handling of narrow channels (voice) as well as broadband channels (video, data).
Other key features:• Use of 6, 7 and 8 MHz channel BW or available separate TV
channels, optional use of 2 channels bonding • Power concentration (up to 15db) to boost selective sub-
channels to increase range• Efficient use of operator spectrum resources• Small data granularity (high statistical multiplexing gain)• Excellent reuse factor (close to 1)
High spectral efficiency in single/multi cell environment
Key design Considerations
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 7
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Submission
• Supports adaptive modulation on a per sub-channel basis• Excellent handling of interference -- Narrow band
interference is rejected through frequency domain processing, while Burst interference is rejected by virtue of the OFDMA symbol length and the per sub-channel interleaving
• OFDMA supports advanced ranging based on identification of CDMA codes
• Extremely efficient BW-Request mechanism (90%, CDMA over OFDMA)
Extremely low network and user equipment prices
Key design Considerations
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 8
doc.: IEEE 802.22-06/0030r0
Submission
System Parameters Parameters Specification Remark
Frequency range 54~862 MHz
System Capacity 75 Mbps (In a cell of 20 km radius) Satisfying user requirements
Based on typical deployment scenario using population density of 1.25 persons per 1 sq. km
Modulation QPSK, 16QAM, 64QAM On both Uplink and Downlink
Transmit power 4W EIRP per CPE According toFRD Requirement
Multiple Access Adaptive OFDMA on both Uplink and Downlink
FFT Mode 512, 1k and 2kModular Approach, reuse of the same modem in other available TV channels
Cyclic Prefix Mode 1/4, 1/8, 1/16, 1/32
Duplex TDD ( or FDD in the future)
Network topology p-to-mp
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 9
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Submission
1. System capacity versus range
• Minimum requirement for system capacity within a cell of 33km radius with density population of 1.25 persons/ sq. km versus 12 active users within the cell
2. Use of multiple TV channels may be useful (contiguous or not). (Note: 802 commented to the FCC that channel bonding SHOULD NOT be permitted to be persistent
Addressing inconsistencies in FRD
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 10
doc.: IEEE 802.22-06/0030r0
Submission
• Spectrum availability
• Effects of narrowband jamming
• Scalability
• HW Complexity
• Unintentional Denial of service
• Reuse of the spectrum
• Computational Complexity
• deployment in Large cells
• Macro Diversity
Part 1
Part 2• OFDMA based Proposal
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 11
doc.: IEEE 802.22-06/0030r0
Submission
Spectrum availability
Constraints on using 3channels bonding
• Three channels bonding is location dependant
• 3 channels bonding is not guaranteed in the future, incumbent services may expand (advent of HDTV), new regulatory scheme will admit new services. WIMAX Forum may succeed in migrating to UHF band and deployment in urban and semi-urban areas.
• In most cases, only partial use of the 3 channels bonding is possible
• SP`s should be assured of non interrupted service even within the constraints of WRAN deployment
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 12
doc.: IEEE 802.22-06/0030r0
Submission
3 Contiguous TV channels
Jamming will affect only one channel that can be mitigated by elimination of sub-carriers affected and regrouping again of the sub-channels
Effects of narrow band Jamming
• jamming or narrowband interference will effect all sub-channels spread over the entire bandwidth. Will need regrouping of the remaining sub-carriers into new sub--channels
3 Separate TV Channels
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 13
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Submission
Scalability
• Scalability is best served using Modular approach where the single channel attributes can be repeated in other available TV channels whether separate or contiguous . In other words, we recommend reuse of the same OFDMA modem on other available TV channels
• Economy of scale entails reuse of proven OFDMA modems to be shortly available meeting one of 16e profiles, such as WiBro, WiMAX )
• We have to realize that WRAN is operating on un-licensed band and as such there is no guarantee that 3 contiguous channels can be exploited most of the time
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 14
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Submission
HW ComplexityBoth BS and CPE
• Need for highly expensive Linear PA in the BS for each sector in channels bonding scenario
• Not to exceed EIRP of 4W on each TV channel will need a computational process to ensure that power boosting or power concentration on some Sub-channels (spread on the entire 3 channels) will not exceed the 4W average limit. This may raise concern of incumbents.
• FRD does not support use of contiguous channel bonding on prolonged time
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 15
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Submission
Unintentional Denial of Service
• WRAN SP is expected to provide services on continual and fair basis, even with the use of one TV channel.
• SP should be capable of providing the needed capacity within his coverage area with the use of one TV channel and WRAN system should be deployed accordingly
• Users at the edge of the cells are therefore subject to an unintentional denial of service once one or two TV channels need to be vacated
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 16
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Submission
Reuse of the Spectrum
• Spectrum availability within the service area may not allow use of the 3 channels bonding or multiple TV channels
• WRAN Deployment will have to be based on reuse of the spectrum in adjacent cells within the coverage area and achieve reuse factor of 1
• Deployment in large cell to achieve range of 30km , in fact, negates SP business rationale
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 17
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Submission
Computational Complexity
• Managing a large base of sub-channels
• Frequent need for regrouping of the sub-carriers in face of band shrinkage due to interference, jamming or in case of vacation of one or two TV channels
• Modular approach where separate TV channels can be exploited can eliminate computing complexity. Other advantage is use of proven design and implementation of several 16e profiles.
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 18
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Submission
Deployment in large cells
• 3 Channel bonding cannot satisfy capacity requirement in large cell (33 km radius), considering population density within the cell as referred to in FRD • From the standpoint of Service Provider it is imperative to offer continuous service with the needed capacity within the cell with the use of only one TV channel, user satisfaction is important, sustainable service is important• Exhausting energy to reach few users located on the edge of the cell who happened to need the service in the same time is not really appealing to SP`s. • Capacity will have the upper hand in the game of trade offs between capacity and range. Range can be extended using repeaters. • Our expectation is that WRAN will also be deployed in semi-urban areas where more populated areas are expected, hence more cell capacity is needed.
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 19
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Submission
Deployment in large cells
30 km radius
Simple Business Model for rural area• Cell size of 30km radius- 28,260 Sq Km
• Population density, 1.25 persons/sq km.
• Estimate number of Households and businesses within the service area is 12,000.
• Assume a Penetration rate of 30%, 8% of the subscribers are active in the same time. Peak data rate on DL is 1.5Mbps and average data rate on the DL is 400Kbps.
• Capacity needed on the DL (assuming 75% use of cell capacity) will be 150Mbps
Highly conservative estimate of
capacity needed is 150Mbps
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 20
doc.: IEEE 802.22-06/0030r0
Submission
Proposed WRAN Base Station (6 Sectors Antenna Pattern)
• Use of antenna of 15 dBi gain
• Use of 3 separate TV channels
F1
F1F2
F2
F3
F3
• Offer better use of the spectrum,
• Low cost Linear PA for each sector,
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 21
doc.: IEEE 802.22-06/0030r0
Submission
Base Station Antenna Pattern
Commercial antenna of 15 dBi gain in the operating frequency
As the FFT size gets bigger, the spectral mask improves, the amount of Guard Interval needed to mitigate the channel reduces, and the phase noise demands increase (there is no implementation problem).
OFDM Spectrum
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 26
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Submission
Using OFDMA/TDMA, Sub Channels are allocated in the Frequency Domain, and OFDM Symbols allocated in the Time Domain.
OFDMA-TDMA Principles
TDMA
TDMA\OFDMA
t
N
m
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 27
doc.: IEEE 802.22-06/0030r0
Submission
DownLink OFDMA Symbol (example)
Total Frequency BandGuard Band Guard Band
Symbol PilotsSub-Channel Data Carriers
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 28
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Submission
PHY preliminary proposal
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 29
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Submission
Duplexing Technique
• TDD
Multiple Access Method
• TDMA/OFDMA
OFDM Symbols allocated by TDMA
Sub-Carriers within an OFDM Symbol allocated by OFDMA
Diversity
• Frequency, Time, Code, Space
Basics
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 30
doc.: IEEE 802.22-06/0030r0
Submission
TDD (Time Division Duplexing) Uses the same frequency for the Downlink and the Uplink.
In any configuration, the access method is OFDMA/TDMA .
F1 - Frequency band
UpLink
F1 - Frequency band
DownLink
Duplexing - Principles
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 31
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Submission
Frame Structure
Allowing Flexibility in DL/UL segmentation
3 possible Preamble structure
FCH and MAP transmitted in PUSC (for better coverage)
Flexible Subchannels allocation per sector on a frame by frame basis
All zones are flexible to produce any scenario needed (reuse =1, reuse < 1, STC/AAS)
Zone may be used as broadcast [SFN] with permutation adjustment
STC/AAS may be combined with regular mode of operation
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 32
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Submission
Preambles
3 possible Preamble structure, more than 114 preambles over all
Preambles are designed for low PAPR (about 5dB or less)
Preambles are boosted due to low PAPR
Preambles are used for channel estimation, frequency estimation, timing estimation and cell monitoring
(optional)• Block size depend on code/modulation/coding rate used
and HARQ usage• Block size is enlarged as allocation get bigger, limited by a
law to constrain decoder complexity (concatenation rules)• Bit-Interleaving over each encoded block
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 35
doc.: IEEE 802.22-06/0030r0
Submission
DownLink/UpLink Block Diagram
Randomiz-ation
Bitinterleaving
Sub-ChannelMapper
IFFT
De-Randomization
BitDeinterle-
aving
Sub-ChannelDemapper
and AdapterFFT
DownLink/UpLink Encoding and Modulation
DownLink/UpLink Demodulation and Decoding
DownLinkTx
Low MacData From MACand Adaptation
Layers
Sub-ChannelAllocation and
BoostingFEC Encoder
DownLinkRx
ChannelEstimation
Low MacData To MAC
and AdaptationLayers
FEC Decoder
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 36
doc.: IEEE 802.22-06/0030r0
Submission
• Dual binary CTC – The best solution for high coding gain using small blocks.– Reduced decoding power per bit compared to regular CTC.– Gives very good performance even for small number of iterations
Coding Schemes
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
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Submission
Down-Link
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 38
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Submission
There are two basic modes of operation:
• Reuse smaller than 1: Sub-Channels (SC) are divided up to 3 Logical-Bands PUSC (Partial use of SC), the structure enables each Logical-Band to have the frequency diversity properties of the full channel, but using only a part of the frequency carriers. The splitting will enable to boost the transmitted carriers on the expense of the un-transmitted carriers ~(4.8 dB)
• Reuse Of 1: Using PUSC or FUSC (Full use of SC) where all subchannels are used. Cell configuration differ by different permutation enabling a reuse of 1.
Reuse
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 39
doc.: IEEE 802.22-06/0030r0
Submission
• The Carriers of each Sub-Channel are spread all over the usable frequency for best frequency diversity.
• The allocation by permutation gives an excellent Reuse factor - almost 1.
• The allocation by permutation give an excellent interference spreading and averaging.
Using Special Permutations for carrier allocation
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 40
doc.: IEEE 802.22-06/0030r0
Submission
DownLink Allocation example
(each color - different allocation)
FCH
Time
Sub-channel
16
0
0 2 4 6 10 12 14 16 18 20 22 24 26 28 30
Frame start (n) Frame start (n+1)
DL UL
Pream
ble
DL
and
UL
MA
P
328
Burst#1
Burst #3
Burst #2
Burst #7
34 36 38 40 42
Burst #4
Burst #5
Burst #6
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 41
doc.: IEEE 802.22-06/0030r0
Submission
• Forward APC per Sub-Channel• Improves the coverage and reduces the interference
between sectors in both Uplink and Downlink• Enabling the same link budget in the Uplink, for a much
(CTC)/BTC, with coding rates = ½, 2/3, ¾, 5/6 • Additional repetition coding of X2, X4 and X6• QPSK, 16QAM, 64QAM adaptive modulation• Different Preamble structure for each sector• Pilots embedded within the Symbol Structure(FUSC), or
associated per allocation of subchannels (PUSC).• 60 Sub-Channels of 48 data subcarriers each (PUSC), for 2k
FFT• 32 Sub-Channels of 48 data carriers each (FUSC), for 2kFFT
DownLink Specification
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 44
doc.: IEEE 802.22-06/0030r0
Submission
• Slot Structure is defined differently in each mode: one Sub-channel in the Frequency domain and 1 OFDMA time symbols in the time domain (FUSC), one Sub-Channel in the frequency domain and two OFDMA symbols in the time domain (PUSC). Each slot consists of 48 data modulated carriers.
• Adaptive Modulation and Coding per Allocation in the Down-Link
• Forward APC controlling (+9dB) – (-18dB) digital gain on the transmitted Sub-Channel
DownLink Specification
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 45
doc.: IEEE 802.22-06/0030r0
Submission
DownLink 1
Planned for best Speed / delay spread performance
Each Cluster can be estimated by itself (self contained)
Major Groups include 24/16 clusters (12/8 Subchannels), for an overall 60 Subchannels
60 permutations are possible
Subchannel carriers are spread all over the specific Major Group’s clusters using RS permutation
Clusters are spread all over the spectrum using a permutation
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 46
doc.: IEEE 802.22-06/0030r0
Submission
DownLink 2
Planned for best Speed / delay spread performance
Planned for a reuse of 1
Pilot periodicity of 2 symbols
32 Subchannels per symbol
32 permutations are possible
Subchannel carriers are spread all over the spectrum using RS series
All Symbol is estimated as a contiguous block
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 47
doc.: IEEE 802.22-06/0030r0
Submission
Total Frequency band
Guard Band
Guard Band
cluster 0 cluster 1
cluster 2cluster 3
cluster 119cluster 118
1. Dividing the subcarriers into 120 physical clusters. Each cluster contains 14 adjunct subcarriers:
• The CDMA like synchronization is achieved by allocating several of the usable Sub-Channels for the Ranging process, the logic unit they consist is called a Ranging Sub-Channel.
• Onto the Ranging Sub-Channel users modulate a Pseudo Noise (PN) sequence using BPSK modulation
• The Base Station detects the different sequences and uses the CIR that he derives from the sequences for:– Time and power synchronization– Decide on the user modulation and coding
Using CDMA like modulation for Ranging
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 58
doc.: IEEE 802.22-06/0030r0
Submission
Ranging Signals
• Using CDMA over OFDMA modulation• ranging designed for Reuse of 1 and Reuse <1• Short ranging is used for BW request and periodic ranging• Amount of Codes for each purpose is set by the MAC• Each sector has its own ranging codes• Using 144 Subcarriers as the basic transmission block (6
data Subchannels of the mandatory UL mode)• BPSK modulation onto used carriers
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 59
doc.: IEEE 802.22-06/0030r0
Submission
• Using the CDMA over OFDMA ranging method enables:• A very robust mechanism for ranging• The same mechanism for timing and power ranging• A very efficient mechanism for maintenance ranging• A very efficient mechanism for bandwidth request• Latency is improved by factor of 4, efficiency by factor of 6
Ranging Efficiency
0 1 2 3 4 5 6 7 8 9 100
0.5
1
1.5
2
2.5
Collision expectation value
Su
ce
ssfu
l B
W r
eq
ue
sts
pe
r slo
t
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 60
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Submission
Hybrid ARQ (HARQ)
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 61
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Submission
• To be used to overcome unknown channel conditions. • Whenever the first transmitted block fails to decode, the
decoder use the ACK/NACK protocol to request additional portion of the encoded block.
• Second transmission of the block may be a repetition of the first one and/or additional parity bits.
• The decoder combines the sum of all transmission and attempts to decode. This scheme is repeated until successful or dropped by the MAC layer.
• Incremental Redundancy (IR) and Chase combining H-ARQ schemes.
– Use two receive chains– Combine the signals in the frequency domain– Equivalent channel response combines the best of both receive chains
• Diversity gain is 5-20dB (omni antennas)
Antenna #2
Antenna #1
Frequency
Amplitude(dB)
Frequency
Amplitude(dB)
Combined
Combine twoantennas
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 65
doc.: IEEE 802.22-06/0030r0
Submission
Txdiversityencoder
IFFT DACFilter RF
IFFT DACFilter RF
Subcarrier modulation
IFFT input packing
Tx
Rx
RF DAC Filter FFT Diversity Combiner
Sub-channel demod.
Log-Likelihood
ratiosDecoder
STC
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 66
doc.: IEEE 802.22-06/0030r0
Submission
RF DAC Filter FFT
Sub-channel demod.
Log-Likelihood
ratiosDecoder
Rx
RF DAC Filter FFT Diversity Combiner
IFFT DACFilter RF Subcarrier modulation
Sub-Channel Allocation Tx
Receive Diversity
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 67
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Submission
Power Amplifier Efficiency
PAPR Reduction
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 68
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Submission
• In the Up Stream due to Sub-Channel allocation (29 carriers from 1711 usable per OFDM symbol) a 17.7dB gain is achieved for one Sub-Channel allocation, an additional 1-2dB gain is achieved due to lower crest factor for the Upstream.
• Due to relatively high PAPR (8-10dB) a RF amplifier linearization technology will be used to minimize the need of power backoff from the RF amplifier
Combined A-XNN and OFDMA gives the optimal solution for WRAN
• No need for higher supply voltage - • Double (or more) power output per transistor
=> Savings in Silicon “real estate”.
Power Amplifier Efficiency
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 71
doc.: IEEE 802.22-06/0030r0
Submission
• OFDMA-2048, 64-QAM PAR is 8.0dB @10-11
– requires 8.0dB backoff
• A-XNNR can reduce backoff to 3.5 - 4dB:
– Increases PA efficiency by >50%
– 100-200% more output power per transistor
Power Amplifier Efficiency
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 72
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Submission
Simulation Results
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 73
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Submission
WRAN expected performance Illustrated Example
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 74
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Submission
• Subscriber Units at the Current OFDMA Symbol = 3
• Sub-Channels Allocated to Subscriber-Unit #1 = 12
• Sub-Channels Allocated to Subscriber-Unit #2 = 9
• Sub-Channels Allocated to Subscriber-Unit #3 = 6
• Number Of New Subscriber-Units Requesting Services = 3
All Subscriber Units Suffer Different Multi-Paths and different Attenuation's
WRAN expected performance
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 75
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Submission
• Constellation at the Base Station
WRAN expected Performance
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 76
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Submission
• Users Separation
WRAN expected Performance
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 77
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Submission
• User Estimation
-2 -1.5 -1 -0.5 0 0.5 1 1.5 2
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
Constellation to Estiamte
-2 -1.5 -1 -0.5 0 0.5 1 1.5 2
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
Estimated vec
WRAN Expected Performance - Results
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 78
doc.: IEEE 802.22-06/0030r0
Submission
-2 -1.5 -1 -0.5 0 0.5 1 1.5 2
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
Constellation to Estiamte
-2 -1.5 -1 -0.5 0 0.5 1 1.5 2
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
Estimated vec
• User Estimation
WRAN expected Performance - Results
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 79
doc.: IEEE 802.22-06/0030r0
Submission
-2 -1.5 -1 -0.5 0 0.5 1 1.5 2
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
Constellation to Estiamte
-2 -1.5 -1 -0.5 0 0.5 1 1.5 2
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
Estimated vec
• User Estimation
WRAN expected Performance - Results
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 80
doc.: IEEE 802.22-06/0030r0
Submission
0 20 40 60 80 100 120 1400
50
100
150
200
250
300Despreading on All Users
• Finding New CPE`s-Units Requesting Services, Using the Ranging Pilots (CDMA/OFDM Techniques)
WRAN expected performance - Results
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 81
doc.: IEEE 802.22-06/0030r0
Submission
Using a Reuse Factor of 1
By allocating different Sub-Channels to different sectors we can reach a reuse factor of 1 with up to 12 sectors (changing the polarity enhances the performance)
HorizontalSub-hannel
s Set 1F1
VerticalSub-hannel
s Set 1F1 V
ertic
alS
ub-h
anne
ls
Set
2F
1
Hor
izon
tal
Sub
-han
nel
s S
et 2
F1
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 82
doc.: IEEE 802.22-06/0030r0
Submission
Coverage Patterns1 frequency, 2 frequencies
1 Frequency C/I = 2 - 10 dB
2 FrequenciesC/I = 10 -29 dB
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 83
doc.: IEEE 802.22-06/0030r0
Submission
Coverage Patterns3 frequencies, 6 frequencies
3 Frequencies C/I = 18-30 dB
6 FrequenciesC/I = 22-30+ dB
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 84
doc.: IEEE 802.22-06/0030r0
Submission
Applicable Spectrum mask (DVB-RCT System) OFDMA based UpLink , 2kFFT
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 85
doc.: IEEE 802.22-06/0030r0
Submission
Working with Different Interferers
Partial Band Jamming and Coexistence with IEEE802.11a, HiperLAN2 systems –
• Interference detection combined with smart ECC, enabling erasures on disturbed carriers
• The OFDMA (2k mode) has a 15dB “processing gain” against wide band Jammers or other 802.11a, HiperLAN2 interferers
carrier of largeFFT size
Power = P'
Frequency
carrier of smallFFT size
Power = P'
for the large sizeFFT we get
dBJammeraOFDMA
N
S1511.802
for the Small sizeFFT we get
dBJammerOFDMAa
N
S011.802
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 86
doc.: IEEE 802.22-06/0030r0
Submission
RF Sensing ProposalRF Sensing Proposal
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 87
doc.: IEEE 802.22-06/0030r0
Submission
BACKGROUND
• Spectrum usage of TV broadcast industries– the average TV market in the United States uses approximately 7 high-power channels of the
67 that it is allocated. This leaves an abundance of free channels that could be used for wireless access.
– With both the House and the Senate having recently passed bills requiring television broadcasts to switch from analog to digital sometime in early 2009, the 700-MHz band (channels 52 to 69) will be cleared of programming and moved to lower frequencies (channels 2 to 51). The 700-MHz band will be set aside for public-safety emergency transponders and for bidding by wireless networks.
in this proposal only channels 2 to 51 are considered.• Three possible ways suggested in one article to protect interference with incumbent
users– Listen-Before-Talk (LBT)– Geolocation/Database: GPS receivers installed in CPEs– Local beacon: locally transmitted signal used to identify incumbent users
Unused Digital TV Channels Could Increase U.S. Wireless Access, Federal action could allow unused channels at lower frequencies to be used for unlicensed wireless networks, Eric S. Crouch, Medill News Service, PC World, Saturday, November 19, 2005, http://www.washingtonpost.com/wp-dyn/content/article/2005/11/18/AR2005111800083_pf.html
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 88
doc.: IEEE 802.22-06/0030r0
Submission
CHANNEL AVAILABILITY
• Questioned whether there will be significant channel availability for unlicensed use in major urban areas during the DTV transition.
– There is likely to be substantial channel availability during transition.– The issue of channel availability during the DTV transition is likely to be short-lived.– In rural areas, there is spectrum available now and there will be for the foreseeable future.
• Bill Rose’s email to 22 email reflector, Wed, November 23, 2005 10:05 am – “The analysis shows that even in congested markets like Dallas/Ft. Worth, 40 percent of the
TV channel spectrum will remain unused after America's DTV transition. In more rural markets like Juneau, Alaska, as much as 74 percent will be available.”
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 89
doc.: IEEE 802.22-06/0030r0
Submission
TV CHANNELS IN U.S.
• Currently with 6 MHz bandwidth for each channel,– VHF low band: Chs 2-6 54-88 MHz
• In this proposal, channels after DTV transition are considered.– Enough channels are expected to be maintained for WRAN.
• For other bandwidths – 7 and 8 MHz – the system concept can also be applied by changing system parameters.
* Ch 37 is reserved for radio astronomy
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 90
doc.: IEEE 802.22-06/0030r0
Submission
SPECTRA OF TV CHANNELS
Analyzing the Signal Quality of NTSC and ATSC Television RF Signals.htm, Glen Kropuenske, Sencore
NTSC and DTV signal spectra
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 91
doc.: IEEE 802.22-06/0030r0
Submission
NTSC TELEVISION BAND
Conventional Analog Television - An Introduction
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 92
doc.: IEEE 802.22-06/0030r0
Submission
DTV PILOT FREQUENCY
Conventional Analog Television - An IntroductionPresented at the IEEE Broadcast Technical Society 49th Symposium September 24, 1999
Henry Fries and Brett JenkinsThales Broadcast & Multimedia, Inc.
Southwick, MA
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 93
doc.: IEEE 802.22-06/0030r0
Submission
DTV SIGNAL VIEWED ON A SPECTRUM ANALYZER
Conventional Analog Television - An IntroductionPresented at the IEEE Broadcast Technical Society 49th Symposium September 24, 1999
Henry Fries and Brett JenkinsThales Broadcast & Multimedia, Inc.
Southwick, MA
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 94
doc.: IEEE 802.22-06/0030r0
Submission
DTV OUT-OF-BAND“SHOULDERS”
Conventional Analog Television - An IntroductionPresented at the IEEE Broadcast Technical Society 49th Symposium September 24, 1999
Henry Fries and Brett JenkinsThales Broadcast & Multimedia, Inc.
Southwick, MA
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 95
doc.: IEEE 802.22-06/0030r0
Submission
VSB TV PARAMETERS (1)
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 96
doc.: IEEE 802.22-06/0030r0
Submission
VSB TV PARAMETERS (2)
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 97
doc.: IEEE 802.22-06/0030r0
Submission
PROTECTION OF PART 74 DEVICES (1)
• Most microphones use analog modulation (FM)• Bandwidth:200 KHz• Power: max. 250 mW (24 dBm) in UHF band
– But usually operate at less than 50 mW– Ex. Power 10 mW, antenna gain -10 dBi, body absorption 27 dB, range 100 m, then
mim. received power level: -95 dBm• Required WRAN CPE out-of-band emission level to protect Part 74
devices: 6.2 uV/m (15.8 dBuV/m measured at 3 m in 120 KHz)• Path loss needed between microphone receiver and L-E devices beyond 1
m (required D/U = 20 dB)– High power WRAN devices (4 W): 129 dB– Low power L-E devices (100 mW): 113 dB
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 98
doc.: IEEE 802.22-06/0030r0
Submission
PROTECTION OF PART 74 DEVICES (2)
• Mitigation techniques– Dynamic frequency selection (DFS)
• Sensing, detection, DFS network behavior to avoid hidden nodes• Practical sensing threshold: -107 dBm in 200 KHz• Max. sensing distance for
– Unfaded microphone: 8.7 Km (free space)– Faded (27 dB) microphone: 400 m (free space)
• Interference margin at edge of sensing contour for faded microphone:– High power WRAN devices (4W): -56.1 dB– Low power L-E devices (100 mW): -40.4 dB
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 99
doc.: IEEE 802.22-06/0030r0
Submission
METHOD 1 (1) SENSING INCUMBENT SIGNALS
• TV band signal sensing for one channel band– Use only spectral components – not time domain components
• Less sensitive on other parameters used to design TV band tuners – for example, Phase noise, etc.
– Use FFT transform of received TV band signals at the receiver for only one TV band or a few bands• After wide band tuning and down converting or down converting and low pass filtering
– One example• BW=F=6 MHz for one band case• Sampling interval T=1/B=1/6 us, sampling rate=BW=6 MHz• Frequency resolution (or frequency separation) F0=3 KHz• Time period T0=1/F0=1/3 ms• Number of samples needed N0=T0/T= 2 KHz• Needs 2K point FFTs
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 100
doc.: IEEE 802.22-06/0030r0
Submission
METHOD 1 (2) SENSING INCUMBENT SIGNALS
T00
t
T
F0
f
F0
Sense antenna
LNAcos2fptwhere fp: left edge freq. of the channel
LPF ADC FFT detector
Discrete Fourier Transform
Sense Receiver Structure
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 101
doc.: IEEE 802.22-06/0030r0
Submission
METHOD 1 (3) SENSING INCUMBENT SIGNALS
• Sensing procedure for TV signals– Several to many frequency components taken in a 6 MHz band depending on the sensing
accuracy• for ex., F50, F103, F200, F417, and F1200
– Compare these values• Correlation method: compare the shape of spectrum of received signals
– Calculate correlations with pre-stored values for NTSC and DTV signals– If one of these values is larger than predetermined values, the judgment is that NTSC or DTV signal
exists.• Pilot detection method: check whether a pilot signal exists
– Calculate the ratio of pilot component to another component– If F417/F1200 > thn, this signal is NTSC– If F103/F1200 > thd, this signal is DTV
– Average frequency component values for several symbol periods to have better sensing results
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 102
doc.: IEEE 802.22-06/0030r0
Submission
METHOD 1 (4) SENSING INCUMBENT SIGNALS
• Sensing procedure for wireless microphone signals– Two types of wireless microphone systems according to frequency usage
• Single frequency systems• Frequency agile systems
– Wireless systems should NOT be operated on the same frequency as a local TV station. • Only open (unoccupied) frequencies should be used. In the U.S., each major city has different local TV stations.
– Microphone signal detection procedure: sensing the spectral components using FFT devices• For ex., for every 3 KHz in a 6 MHz band a spectral component is measured and compared with other components: two comparison
methods used for DTC and NTSC signals can be applied• If considerable components in a 200 KHz band exist, a wireless microphone is considered to be operated in that band:
– For the previous case, if consecutive six components spaced equally in 200 KHz have considerable amount of energy, a microphone signal is detected.
• Or much correlation with stored microphone signals exists, a wireless microphone is considered to be operated in that band.
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 103
doc.: IEEE 802.22-06/0030r0
Submission
METHOD 2 (1)
SENSING INCUMBENT SIGNALS
• After DTV transition in the U.S.,– VHF low band: Chs 2-6 54-88 MHz– VHF high band: Chs 7-13 174-216 MHz– UHF band: Chs 14-51 470-698 MHz *
• n consecutive bands in VHF High or UHF band selected for WRAN services– The whole band of n bands is divided into n*l subbands
• Each band has l subbands; each subband has 6000/l KHz bandwidth– At receiver, the received signal after down conversion is inputted to a l*n point FFT
• By comparing FFT output signals, currently operated incumbent users can be identified and categorized – NTSC, DTV, or Part 74 devices
• With this method all incumbent signal throughout the whole band (n TV bands) can be detected simultaneously
– Periodically all CPEs and BSs can do this sensing to update the list of active incumbent users
* Ch 37 is reserved for radio astronomy
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 104
doc.: IEEE 802.22-06/0030r0
Submission
METHOD 2 (2) SENSING INCUMBENT SIGNALS
• NTSC signal sensing– After down conversion with (fp+1.25) MHz frequency shift, the received signal is inputted to
l*n point FFT devices– Compare the FFT outputs
• DTV signal sensing– After down conversion with (fp+0.30944) MHz frequency shift, the received signal is inputted
to l*n point FFT devices– Compare the FFT outputs
• Part 74 device sensing– After down conversion with fp MHz frequency shift, the received signal is inputted to l*n point
FFT devices– Compare the FFT outputs
• Various comparison methods can be considered– Correlation method or pilot detection method used in Method 1 is suggested for TV signals – If some consecutive strong components in 200 KHz exist, Part 74 device is considered to
operate in this band. Or correlation method will be applied for Part 74 device signals.
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 105
doc.: IEEE 802.22-06/0030r0
Submission
METHOD 2 (3) SENSING INCUMBENT SIGNALS
• Select k consecutive bands out of n bands
f
Band 0 Band 1 Band k-1Selected bands
subband 0subband 1
subband 2
subband l-1
WRAN Incumbent user WRANWRAN/incumbent
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 106
doc.: IEEE 802.22-06/0030r0
Submission
SPECTRAL CORRELATION (EXAMPLE)
8 measured spectral components
Using 8 measured components, a correlation is calculated.
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 107
doc.: IEEE 802.22-06/0030r0
Submission
PROPOSED RECEIVER STRUCTURE
• At receiver, data receiving and incumbent signal sensing are executed simultaneously.
– Without having separate receiving and processing branches– Using sensing method 2– If more precise sensing is needed, sensing method 1 may be applied with an additional
signal processing block – needs one more ADC and FFT.
receive antenna
LNAcos2fptwhere fp: left edge freq. of the channel (or whole target band)
LPF ADC FFT
detector
demod
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 108
doc.: IEEE 802.22-06/0030r0
Submission
ADVANTEGES OVER OTHER PROPOSED SCHEMES
• Advantage over energy detection including MRSS– At one measurement, all frequency components can be extracted: whole frequency
band can be covered for one FFT symbol duration : faster than MRSS which uses sweep oscillators.
– Correlation detection not energy detection: more intelligent sensing than MRSS
• Advantage over cyclostationary feature sensing– Can detect Part 74 device signals while cyclostationary sensors can not detect them
while NTSC and DTV signals can be detected relatively much easier than Part 74 signals.
• Advantage over other proposed schemes– Need not more hardware to sense: can use OFDM receiving blocks: only a detector
should be added for sensing– Faster and simpler than other proposed schemes
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 109
doc.: IEEE 802.22-06/0030r0
Submission
Tuner
AGC-RF
SAW6MHz BW AMP
IF OUT
IF 36MHz
Freq InfoFrom WRAN
Modem
BPFLNA
NF=7dB
470-860MHz
From Processor
A/D10b
Demod.FFTTo Processor
To Analyze AndReport
Signal Signatures
Alternative WRAN Sensing scheme
• Scanning of +/- 8 channels from both sides of WRAN operating channel
• 50 steps of 2MHz each fed to the tuner
• Extracting signal signature within the scanned band will take 15 msec
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 110
doc.: IEEE 802.22-06/0030r0
Submission
MAC ProposalMAC Proposal
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 111
doc.: IEEE 802.22-06/0030r0
Submission
MAC Proposal Outline
• Network Entry and Initialization– 802.16 based solutions
• Class of Services and Quality of Services– 802.16 based solutions
• Support for Interference Mitigation and Coexistence– New solutions proposed
• OA&M Support– To be defined
• Base Station and CPE Address Space– 802.16 based solutions
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 112
doc.: IEEE 802.22-06/0030r0
Submission
Support for Interference Mitigation and Coexistence
• Protections of licensed incumbent services– 802.22 Sensing Algorithm– RF Sensing and DFS Control– DFS Messaging Control
• LE systems coexistence and sharing– Spectrum sharing mechanism– Inter-system communications
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 113
doc.: IEEE 802.22-06/0030r0
Submission
Protections of Licensed Incumbent Services
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 114
doc.: IEEE 802.22-06/0030r0
Submission
Tenets for Incumbent Protection• Whenever possible, make use of database
information containing channel availability information (location-dependent)
• Maintain a “candidate set” of available channels in case current channel needs to be vacated
• Periodically monitor channel (s) currently in use (i.e., “in service” monitoring)
• Sensing parameters (channel availability check time, etc.) to be optimized for agile service deployment
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 115
doc.: IEEE 802.22-06/0030r0
Submission
Sharing Frequency Bands in 802.16
• Section 6.3.15 of the 802.16-2004 provides information on DFS
• Facilitates spectrum sharing in license-exempt spectrum• Provides for primary user detection and avoidance,
uniform spreading in the band of operation and TPC (tx power control)
• Primary users – defined by regulation to take priority in the band(s)
• Defining the use of aspects of DFS for ACS (Adaptive Channel Selection) for avoiding general other user or system interference.
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 116
doc.: IEEE 802.22-06/0030r0
Submission
DFS in 802.16
Within 802.16-2004 (section 6.3.15) plus cor1 the DFS procedures, for detection of Primary User of the license-exempt bands, provide for the following:
• Testing channels for primary users• Discontinuing operations after detecting primary users• Detecting primary users• Scheduling for channel testing• Requesting and reporting of measurements• Selecting and advertising a new channel
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 117
doc.: IEEE 802.22-06/0030r0
Submission
802.22 Sensing Algorithm
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 118
doc.: IEEE 802.22-06/0030r0
Submission
Service initiation30 sec Channel
Availability Check on next channel
Available?
Choose a different channel
No
In service monitoring of operating channel
YesDetection above
threshold?**
No
Stop transmission
Yes
Select and change to new available* channel in 2 secs with ≤100 ms
transmission time
Channel unavailable for 10 minutes
Log of channel availability
* Available means the channel passes the channel availability check test
Start 10 minute timer
Available?
Yes
No
Background In Service Monitoring (on non-
operational channels)
Background 30 sec Channel Availability
Check
Begin operation on available* channel in 2
secs with ≤100 ms transmission time
** Detection is required within 2 secs of incumbent signal beginning operation
on the channel. Probability of detection ≥ 90%, false alarm rate of ≤ 10%
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 119
doc.: IEEE 802.22-06/0030r0
Submission
RF Sensing and DFS Control
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 120
doc.: IEEE 802.22-06/0030r0
Submission
RF Sensing and DFS Control
• Objectives– Licensed incumbent protection guarantee– QoS Satisfactory for 802.22 systems
• Possible Solutions– RF sensing separated with data transmissions– RF sensing overlapped with data transmissions
• Advantages– Reliable RF sensing (no self-interference)
• Disadvantages– Data services interruption
• Transmission Latency
– Potential low system utilization• System throughput
periodsense
DFSsensesystem T
TTU
_
1
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 124
doc.: IEEE 802.22-06/0030r0
Submission
Simultaneous Selective RF Sensing
• Proposed Solution for RF Sensing Control– Selective RF Sensing with simultaneous data
transmissions
• Properties– Non-interrupted data transmissions– “Full” system utilization– RF sensing performed on selective spectrum
that reliable sensing can be achieved
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 125
doc.: IEEE 802.22-06/0030r0
Submission
Selective RF Sensing
• Guard bands – guarantee reliable sensing– Variable, depending on sensing techniques, tx power, incumbent, etc.
• Adaptive spectrum selection for RF sensing– Optimizing the sensing reliability and QoS using intelligent control
algorithms
– Band to sense, number of channels to sense
Spectrum in useGuard band Spectrum being sensedSpectrum being sensed Guard band
Frequency
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 126
doc.: IEEE 802.22-06/0030r0
Submission
Selective RF Sensing• Provide flexibility of strategic channel selection for
RF sensing, optimizing:– RF sensing performance
– QoS of 802.22 systems
• Flexibility of channel selection– Channels to be sensed
• Channels with less probability of incumbent occupancy
– Number of channels to be sensed
– Size of the Guard band• Positive, negative, infinite
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 127
doc.: IEEE 802.22-06/0030r0
Submission
Dynamic Frequency Hopping with Simultaneous Selective RF Sensing
Initial Sensing
Validation time of CH A
Transmitting on CH ASensing on CH ([0, A-n],
[A+n, N])
Less than Grace Period
Validation time of CH B
Less than Grace Period
Transmitting on CH BSensing on CH ([0, B-n],
[B+n, N])
Time
• Validation time – The latest time a channel is validated to be vacant• Grace period – The maximum period of time a incumbent can tolerate interference for LE operations, from the beginning of the incumbent’s operations
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 128
doc.: IEEE 802.22-06/0030r0
Submission
Dynamic Frequency Hopping
• A 802.22 system cognitively and continuously switches operation frequencies for data transmissions.
• Both frequency selections and the length of an operation period on a channel are determined dynamically in runtime by a cognitive engine.
• A 802.22 system transmits data on a frequency for an operation period (DFH Operation Period) whose length is varied and shall not exceed the grace period.
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 129
doc.: IEEE 802.22-06/0030r0
Submission
Dynamic Frequency Hopping
• A 802.22 system performs both data transmissions on a channel, say Channel A, and RF sensing on channels [0, A-n] and channel [A+n, N] in each operation period– Channel “0” and Channel “N”
• Lower bound and upper bound of the sensing spectrum
– “n” is the number of channels in the guard band
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 130
doc.: IEEE 802.22-06/0030r0
Submission
DFH Operation Cycle
• During a DFH operation cycle– BS schedules the system to switch (hop) to channel (set) A
– BS and CPEs perform data transmissions on channel (set) A
– BS performs, and schedules CPEs to perform spectrum sensing on channel [0, A-n] and [A+n, N]
– CPEs report sensing measurement results
– BS performs report processing
– BS performs channel selection and acquisition
– BS announces DFS decision for the next operation cycle
• Verifying the Feasibility of Non-Exclusive Channel Sharing– Channel sharing through transmission power control
(TPC) such that 802.22 systems sharing the same channel do not cause harmful interference to one another
– Non-exclusive spectrum sharing method is feasible as long as the maximum achievable signal-to-interference-ratio (SIR) on the selected channel is higher than the required SIR of the 802.22 for the supported services
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 164
doc.: IEEE 802.22-06/0030r0
Submission
On-Demand Spectrum Contention (ODSC) Algorithm
• Channel Contention for Exclusive Channel Sharing – Facilitated by Inter-System Coordination through
• Associated with one BS (service BS) through service connections;
• Associated with another BS (coexistence BS) through coexistence connections – Coexistence communications
only
BS0 BS1
CPE0
CPE1CPE2
Service connections Coexist connections
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 187
doc.: IEEE 802.22-06/0030r0
Submission
Co-existence Connections• Regular connections
– Carry co-existence communications only
• Established and maintained – Between a bridge CPE and the coexistence BS (C-BS) on
request by the service BS (S-BS)
– Between two BSs • if S-BS is within the arrange of C-BS
• S-BS behaves as a CPE of C-BS in such case)
– On channels occupied by the coexistence BS
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 188
doc.: IEEE 802.22-06/0030r0
Submission
Co-existence Connections
• Establishments/maintenances are performed along with service data transmission– Ranging, connection acquisition– Controlled by S-BS and shall be guaranteed
that they are not co-scheduled with service communications
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 189
doc.: IEEE 802.22-06/0030r0
Submission
LCC Between Two Base Stations
Bridge CPE (associated with BS1)
Serviceconnections
Co-existenceconnection
Co-existenceconnection
BS0 BS1
March 2006
Huawei, NextWave, Runcom, STMicroelectronics
Slide 190
doc.: IEEE 802.22-06/0030r0
Submission
Over-the-Air Co-existence Communications
• S-BS communicates with C-BS for co-existence via B-CPE as a relay
– Communications via Service connection + coexistence connection
– S-BS controls the coexistence operations between B-CPE and C-BS
Conclusion (MAC)• Complete, efficient, and flexible MAC solutions for
interference mitigation and coexistence support• Protections of licensed incumbent services
– Sensing Algorithm based on Database and RF Sensing– RF Sensing Control: Selective Simultaneous RF Sensing– DFS Control: Dynamic Frequency Hopping– DFS Messaging Control based on 802.16 MAC Messages
• LE systems coexistence and sharing– Spectrum sharing mechanism using ODSC– Inter-system communications using LCC