Monday, November 28, 2005

Take a rest

No update today and I'm going to take a vacation for almost 2 weeks.
So, Don;t expect any update for the next two weeks.
Aftre the vacation, I may move to next interesting , which I have not decided yet.

Friday, November 25, 2005

Wi-MAX sc improved

I worked on WiMax-SC to improve its performances.
-DFE is improved to get more accuracy.
-Block Turbo Decoder is improved to get the same architecture as WiMAX OFDM.
- Bug fix of randomizer (inverted bit order)

So, My Wi-Max development has been Almost done.. besides 2 bugs..

Wednesday, November 23, 2005

Wimax-ofdm wrap up

Today, as CTC worked well, I have wraped up WiMax-OFDM.
I have not done AAS/Mesh/subchannelization/MISO &etc..
I'll move to next intersting in the next week.
Also I tried to fix a bug in Wi-Max SC that randomizer's bit order was
The change is easy, but it made some side effects that
BTC and some others got screwed up.
They were not due to the randomizer change,
just different bitstreams makes different results.
And only one out of 200 tests are not passed yet. I'll solve this tomorrow.

Tuesday, November 22, 2005

Problem on CTC encoder.

I could not solve the mismatch I talked yesterday.
So , I decided to change Table 221 Circulation state lookup table.
I know that this is a standard, which I cannot change personally.
But without changeing the table I cannot move forward.
So far , some simple tests with the updated table worked fine in
CTC only environment. And I'm integrating it into OFDM system.

Monday, November 21, 2005


I started CTC encoding and decoding.
The coding is 70% is finished.
I don't really undersatnd How the circulation status is initialized.
I guess the purpose of the initialization makes the last state to zero
in order to add padding bit on the tail of the block for viterbi-decoder.
But the problem is I could not get zero after the encoding process.
I'll solve the problem tomorrow.

Saturday, November 19, 2005

BTC done.

I have done BTC, which is working well now , after I modified a lot today.
The only problem of the BTC is too BIG!! I don't think this can be calculated in ASIC
in reasonable time and cost.
I'll tune the BTC later, but before that I'll do CTC in the next week.

Friday, November 18, 2005

Accidentally passed ??

Today all 200 of tests are passed with BTC.
But I knew the version is not worked as I expected.
So, I believe No error has taken place in modulation(even 64QAM).
The current version does not have capabiltiy to fix errors.
This'll takes more times.