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Re: [STDS-802-16] Questions on P80216-REVd_D5 - reproducing the example in section 8.4.9.4.4 Example of OFDMA uplink CC encoding

Hi Vafa,
 
There is an error in the example (as you identified in 1.)
I have inserted a comment to fix it, and will replace the example with the final stage corrected.
 
Regards,
Yossi

From: owner-stds-802-16@listserv.ieee.org [mailto:owner-stds-802-16@listserv.ieee.org] On Behalf Of Vafa Ghazi
Sent: Friday, November 05, 2004 11:39 PM
To: STDS-802-16@listserv.ieee.org
Subject: [STDS-802-16] Questions on P80216-REVd_D5 - reproducing the example in section 8.4.9.4.4 Example of OFDMA uplink CC encoding

Hi,

 

I have a question regarding the example in “section 8.4.9.4.4 Example of OFDMA uplink CC encoding” of P80216-REVd_D5. Particularly, my question is about going from “Constellation Mapping” (a series of 0.707/0.707 QPSK symbols) to “Mapping onto Subcarriers” (a series of (35,449,-0.707/+0.707) …). I am using the definitions in “section 8.4.6.2 Uplink” and all its subsections. I have two questions:

 

  1. I can follow the pilot locations for symbols 35, 36 and 37. They do follow the definition given in “Figure 236 – Description of an uplink tile”. But I can’t make sense of the pilot locations for symbols 38, 39 and 40. They do NOT follow the definition in Figure 236. Could someone please explain why that is?
  2. Additionally, the QPSK symbols modulating the data subcarriers seem to go through some phase rotation, when going from “Constellation Mapping” to “Mapping onto Subcarriers”. There is a definition for this rotation in “section 8.4.9.4.1 Permutation definition”, but according to this definition, phase rotation is either 0 or 180 degrees (according to the sentence immediately above “section 8.4.9.4.3 Pilot modulation”). But in the given example, I notice there are also phase rotations of 90 and 270 degrees present. Again, does anyone know the explanation for this?

 

Thank you in advance,

Vafa

 

Vafa Ghazi, Ph.D.                                           

Principal Software Engineer                       

SPW Business Unit                                         

CoWare Inc.                                                    

Email: vafa@coware.com