June 2007doc.: IEEE 802.22-07/0305r0

IEEE P802.22
Wireless RANs

Minutes from PHY Conference Call
Held June21, 2007 at 10pm EST
Date: 2007-06-21
Author(s):
Name / Company / Address / Phone / email
Zander Zhongding Lei / Institute for Infocomm Research,Singapore / 21 Heng Mui Keng Terrace,Singapore 119613 / 65-6874-5686 / leizd@i2r.a-star..edu.sg


1.Attendance

Jun 7 / Jun 14 / Jun 21 / Jun 28 / Jul 5 / Jul 12
Myung Sun Song / x
Sung Hyun Hwang / x / x / x
Jung Sun Um / x / x / x
Soo-Young Chang / x / x / x
Edward Au / x / x
Zander Zhongding Lei / x / x / x
Changlong Xu
Monisha Ghosh / x / x
Carlos Cordeiro
Gerald Chouinard / x / x / x
Carl Stevenson
Cheng Shan / x / x
Jinxia Cheng / x
Eli Sofer
Ramon Khalona / x / x
John Benko / x / x
Ivan Reede
Steven Kuffner / x

2.Minutes from June 21 2007 Conference Call

2.1Agenda

  1. Ranging and Subcarrier Allocation (Jung Sun, Ivan, John)
  2. AMC (Jung Sun, John)
  3. DS / US mapping
  4. Low rate coding for range extension

2.2Notes

The meeting was called to order at 10 pm ET.

  1. Ranging and Subcarrier Allocation (Jung Sun, Ivan, John)

Jung Sunupdated further discussions amongst interested people were required to settle the issue.

  1. Adaptive Modulation (Jung Sun, Ivan, John)

The maximum number of subcarriers to be used for AMC mode could be obtained once minimal number of subcarriers for diversity mode to achieve a meaningful diversity gain determined. The group would wait for John to present the number through analysis / simulations in the subsequent calls.

  1. DS / US mapping

Sung Hyun presented doc07-300r0 “Proposed Burst Allocation Method Relating to DS/US-MAP”. Considering various effects, e.g. required bits for DS/US-MAP IE, time diversity gain, partition of subchannel zone, decoding latency, and channel estimation, they proposed to use a linear vertical scheme for DS and US burst allocation. Each US burst in the diversity zone lasted 7 to 13 OFDMA symbol long in time.

Geraldcommented thatthe linear vertical pattern was more vulnerable to impulse noises which might in this case destroy all the information.

Sung Hyunwould look at the potential issues.

Zanderasked about the ball park estimation of required bits of linear pattern vs rectangular pattern.

Sung Hyun/Geraldanswered with rough estimation that linear pattern would have ½ overhead as opposed to rectangular pattern.

Geraldasked whether ranging part in the DS/US map must occupy the whole US in time.

Sung Hyunanswered that it could be shorter in time. The ranging burst in the map would be defined in the UIUC.

Gerald/Zandercommented that it would be better to have more flexibility in the DS/US map and allow some bursts in diversity zone occupying the whole US in time, when necessary.

Sung Hyunagreed to look into it.

  1. Low rate coding for range extension

Monisha updated that the option she was looking at using two ½ rate codecs to generate the ¼ rate codecwas able to achieve around a 4.5 dB gain over a single ½ rate codec, under wireless LAN channels. It was not clear yet how it would perform in the WRAN channels. Comparing with the simple repetition scheme with a typical 3 dB gain over ½ rate coding, the two ½ codecs option would provide 1~1.5 dB gain. She mentioned that the additional complexity at both coder and decoder is minimal.

The group would discuss further in subsequent conference calls.

2.3Next call

The next call will be held on Thursday, June 28 at 9 AM EST. The bridge information(thanks to Gerald of CRC) is as follows:

======

North America: 1-888-265-0903

International: +613-954-9003

Access code: 082942

======

Submission page 1 Zander Lei, I2R