One mistake today…

Today I start with pray. Then brush my teeth and wash my face. I have an appointment with Tere to go jogging at Sabuga. Yeah… We met after several days separated between Bandung and Surabaya. I still feel bitter taste in my tongue. I don’t know. Maybe it is because of my last stomach ache, and some medicine… that toxic me

I start to go to Campus to check my email, friendster, wordpress, and so on. I bring my laptop, but stupidly… I don’t bring both of my battery and  charger.  Ow ow…

I brows in Comlabs for a while… And fortunately, my “broken student card” still works for it.

Thanks God.

Abstract of my Final Project

Here is my final project abstract. The title of my final project is Analysis of Convolutional Coding with Viterbi Decoding Performance via Frequency Non-Selective Rayleigh Fading. You know, this topic came to me when I went to Electrical Engineering Department Library. Mmm, I was inspired by a final project by Yudi Darmadi, EL 99. Thanks, Mas… 🙂


One of the channel coding deployment methods is utilizing convolutional encoder in transmitter side and Viterbi decoder in receiver side. Some parameters influence their performance in correcting error. They are constraint length, polynomial generator, bit number of soft decision, and code rate. This final project gives details about varying constraint length and bit number of soft decision that affect the system performance which is indicated by Bit Error Rate (BER) and energy per normal noise Eb/N0­­ correlation. It also gives details the effects of interleaver and deinterleaver attachment to the communication system performance.

We used computer simulation for modelling the system. There is a final project which explained this problem but only applied Additive White Gaussian Noise (AWGN) channel in the system. Because AWGN channel is not practical, we use frequency non-selective Rayleigh fading channel as a channel transmission.

Here are the results of the simulations. To reach BER 10-3­, at 3-bit soft decision, without interleaver, and 3, 5, 7, 9 constraint length, we need Eb/N0 at 17, 14, 15, and 12.5 dB. It shows that bigger constraint length, lesser the requirements of Eb/N0. Moreover, utilization of 3-bit soft decision gives 2-dB performance better than hard decision. However, more number of bit soft decision, for 10-bit soft decision, the performance is unchanging, but the delay is increase and complexity as well. When we applied interleaver and deinterleaver for 10 bit in the system, to reach BER 10-3, at 3-bit soft decision and constraint length 9, we need Eb/N0 at 6 dB.


Viterbi decoder, Rayleigh fading channel, soft decision, constraint length, generator polynomial, code rate, convolutional encoder

New toy: Skype

Thanks to Kemas Zakki who told me how to use Skype with my laptop in my beloved Campus. Mmm, just configured some port and proxy setting. 🙂 But, yet I don’t have friends who use this skype. only you and Boma (i don’t have it yet), Zak! (my id of skype: arikuncoro) Would you add me as your buddy list? please, do!

By having this account, I have a free call VoIP for the other skype accounts. If I want to call some PSTN number, handphone, or international call, I should have some ‘voucher’ by purchasing it via credit card. It is 10 euro. Sadly, I haven’t credit card yet. So, I just wanna tell you, if you have a laptop, please… have skype ID.. (for my friends who want to keep contact closely by this VoIP tools).

Yahoo and Google also have VoIP tools by Yahoo Messenger and Google Talk. But, I have never tried it before. Therefore I can’t compare them. But, my friends, Komeng and Zakki, said that Skype is the best for VoIP. Another advantage is, in the morning you will see 7 million accounts of Skype online, and it will grow up when in the night, until 12 million people online. Trying to find friends in over the world? It’s easy.

To keep contact with voice, why don’t you try Skype? 🙂

Again, I will thank Zakki for this. Good luck bro, for your Schlumberger career. Hope you will get your dream!

Life is learning, is that so?

I think life is a learning process. It includes study, love, sport, music, and many things that I can learn. Mmm, yesterday, I learned tennis. And really, I have many progress. I played tennis with Komeng, Hendra, and Anjas. We have progress. Such a while we made some rally. Nice. Next sport: Badminton on Friday, July 4th 2008 at 1 pm with my classmates. For me, it is learning.

Love. Mmm, it’s rather sensitive. And I think it’s not quite easy as I think before. I learn to understand a woman. It looks like easy…but… exactly NOT. Even I have made a relationship since eight months ago, still I seldom didn’t understand why she feel something that I thought it’s not important. Yeah… for me, it is learning. Just to adjust my feeling with her… it needs process and understanding.

Study. Mmm, formally, I will get an academic title from ITB. But, I think… it’s just a starting point. I just need some refreshing air to heal… to prepare my new environment then. For me, it’s learning.

Never ending learning,… it’s not about reading. it’s not just about transcript of my GPA. it’s not just about writing. But it’s all about a packet of learning that should I take and combine.