submission doc.: ieee 11-11-1564-00-00ahr0 november 2011 klaus doppler, nokiaslide 1 sequence design...

Submission

doc.: IEEE 11-11-1564-00-00ahr0November 2011

Klaus Doppler, NokiaSlide 1

Sequence design for parallel ACK

• Date: 2011-09-15

Name Affiliations Address Phone email Taejoon Kim Nokia 2054 University

Ave, Suite 600 Berkeley, CA 94703

+15102196813

[email protected]

Zhong-Yi Jin Nokia +16502846138

[email protected]

Sayantan Choudhury

Nokia +15105999268

[email protected]

Klaus Doppler Nokia +15104232458

[email protected]

HongKun Li Nokia [email protected]

Authors:

Submission



Abstract

• Parallel ACK is crucial to the success of Probe and Pull MAC

• This presentation gives more details on the parallel ACK design for 802.11ah

Submission

doc.: IEEE 11-11-1564-00-00ahr0

Klaus Doppler, Nokia

Parallel ACK Mechanism [1]

• STAs having data to send transmits ACKs concurrently (in time-aligned manner)

• Detection at AP impaired by parallel ACKs

Need methods for resolving parallel ACKsSlide 3

November 2011

SIFS

ProbeAP

STA1 ACK

STA2 ACK

STA3

STA4 ACK

PullSIFS

have data to send

have data to send

have data to send

Submission

doc.: IEEE 11-11-1564-00-00ahr0


Parallel ACKs

• Parallel ACKs are separated in code-domain

• Sequence ID identifies STA ID

Slide 4

November 2011

Time for ACK frame

Sequence 1 (STA 1)

Sequence 2 (STA 2)

Sequence 3 (STA 3)

Sequence 4 (STA 4)

Code-domain

Submission

doc.: IEEE 11-11-1564-00-00ahr0


Sequence for STA Identification (1/2)

• Zadoff-Chu sequence ,

• Properties? Zero cyclic autocorrelation

? Minimum cyclic cross-correlation If is relative prime with ,

Slide 5

November 2011

root of sequence integer

length of sequence

Cyclic shift by k

If is prime, the condition is guaranteed

Submission

doc.: IEEE 11-11-1564-00-00ahr0


Sequence for STA Identification (2/2)

• Zero cyclic autocorrelation implies? Cyclic shifts of , i.e., are orthogonal for

? Maximum orthogonal ZC sequences from a single root

• Minimum cyclic cross-correlation implies? If , cyclic cross-correlation between and , where and , has

• Root values and amount of cyclic shifts characterize STA ID

Slide 6

November 2011

Submission

doc.: IEEE 11-11-1564-00-00ahr0


(a) Map a part of ZC sequence to OFDM subcarriers Meet spectrum mask

• Take advantage of existing OFDM structure

• DFT (or IDFT) of ZC sequence has unit amplitude? Limits PAPR and bounds interference to other STAs

Parallel ACK Transmission

Slide 7

November 2011

PART 1 PART 2 … PART 8

ZC sequence for STA1

…

ACK

ACK PART 1 PART 2 … PART 8

STA1

STA2

ZC sequence for STA2

CP part 1

CP part 1

(a)(b)

CP part 8

CP part 8

(a)(b)

(a)(b)

…

(b) IFFT and add cyclic prefix (CP)

ACK_STA1

ACK_STA2Parallel ACKs to AP

Submission

doc.: IEEE 11-11-1564-00-00ahr0

• Sum of ACK packets arrives at AP with delays

? , e.g., for sensors in 1km range for urban macro (SCM [2])

Parallel ACK Reception

Slide 8 Klaus Doppler, Nokia

November 2011

AP ACK_STA1 + ACK_STA2

TFFT TFFT

TRTT: max round-trip time TMD: max. multipath delay

TCP

TRTT

TMD

TCP: CP duration

TCP

CP part 1 CP part 2

CP part 1 CP part 2

……

ACK_STA1

ACK_STA2

Submission

doc.: IEEE 11-11-1564-00-00ahr0


Parallel ACK Detection

• Active user identification? Joint detection of the number of active users and their identities

• Asynchronous detection? Packet arrival with delays (maximum delay with 6us)

• Non-coherent detection? In interference limited scenario (i.e., there are multiple STAs

sending ACKs), channel estimation is challenging

Slide 9

November 2011

Submission

doc.: IEEE 11-11-1564-00-00ahr0


Simulation Setup

Slide 10

November 2011

Channel Bandwidth 2MHz

Channel model SCM Urban Macro [2]

FFT Size/Number of Subcarriers 64/56

IFFT/FFT Period 32us/32us

Max Propagation Delay 6us (1km range)

Cyclic Prefix Duration 12us (> 6us + 2us)

OFDM Symbol Duration 44us (12us + 32us)

ACK Frame Duration (8 OFDM SYMs) 352us

Max Number of Sequences 64

64 ZC sequences

Length of seq. Root index Amount of cyclic shifts

Nzc=443

q=2300 13 26 39 52 65 78 91 104 117 130 143 156 169 182 195 208 221 234 247 260 273 286 299 312 325 338 351 364 377

q=280

0 13 26 39 52 65 78 91 104 117 130 143 156 169 182 195 208 221 234 247 260 273 286 299 312 325 338 351 364 377 390 403 416 429

Submission

doc.: IEEE 11-11-1564-00-00ahr0


Simulation Results

Slide 11

November 2011

Submission



References

• [1] PP MAC contribution

• [2] J. Salo et al, “3GPP Spatial Channel Model,” [Online] Available: http://www.tkk.fi/Units/Radio/scm/

Submission

doc.: IEEE 11-11-1564-00-00ahr0Month Year

John Doe, Some CompanySlide 13

802.11 Template Instructions 1/4

• To properly identify your PowerPoint presentation as an IEEE 802.11 Submission there are 7 steps that you must complete, and 12 data fields that you must fill in.– Step 1. Obtain a document number (has the form yy/xxxx).

– Step 2. Title slide: Fill in the presentation subject title text, the full date (in ISO 8601 format of YYYY-MM-DD), and the complete author(s) details (a total of 3 data fields).

– Step 3. Abstract slide: Fill in the abstract text.

– Step 4. Press “Office” button, Prepare / Properties. Fill in the 2 data fields:

• Author field = first author's name

• Title field = Title of presentation

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802.11 Template Instructions 2/4– Step 5. Menu select View, Master, Slide Master, select the top

master page (theme slide master). Place the document designator in the right hand side of the header.

• Document designator example "doc.: IEEE 802.11-04/9876r0" , or

• "doc.: IEEE 802.11-04/9876r2"

– Step 6. Menu select Insert, Header and Footer (5 data fields):• Slide tab:

– Date & Time, Fixed = venue date (as Month Year, e.g. January 2005)

– Footer = first author, company

• Notes tab:– Data and time, Fixed = venue date (as Month Year, e.g. January 2005)

– Header = document designator (e.g. “doc.: IEEE 802.11-04/9876r0”)

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• Click "Apply to all".

– Step 7. Delete the four template instruction slides.

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802.11 Template Instructions 3/4

• PowerPoint Submission Preparation Summary:– Things to do: 7

– Fields to fill in: 12

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802.11 Template Instructions 4/4Recommendations

– a) Always create a new presentation using the template, rather than using someone else's presentation.

– b) For quick and easy creation of new 802.11 submissions, place the 802.11 template files in the template folder area on your computer. Typical locations are:

• c:\Program Files\Microsoft Office\Templates\802.11, or

• c:\Documents and Settings\User Name\Application Data\Microsoft\Templates\802.11

– To create a new submission from within PowerPoint, menu select File, New, then select the appropriate 802.11 template file.

– c) When you update or revise your presentation, remember to check all 6 fields in steps 5 and 6 for the correct values.

– rev: 2010-03-01

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• [begin placing presentation body text here]

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submission doc.: ieee 11-11-1564-00-00ahr0 november 2011 klaus doppler, nokiaslide 1 sequence design...

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klaus doppler

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sta1ack ack

parallel ack design

sta1 ack

abstractparallel ack

ack framesequence

sequence design