Oleh: volcanon88 | Maret 26, 2009

WCDMA (UMTS)

layersWideband Code-Division Multiple-Access (W-CDMA) is one of the main technologies for the implementation of third-generation (3G) cellular systems. It is base on radio access technique proposed by ETSI Alpha group and the specifications was finalised 1999.

The implementation of W-CDMA will be a technical challenge because of it’s complexity and versatility. The complexity of W-CDMA systems can be viewed from different angles: the complexity of each single algorithm, the complexity of the overall system and the computational complexity of a receiver. W-CDMA link-level simulations are over 10 times more compute-intensive than current second-generation simulations. In W-CDMA interface different users can simultaneously transmit at different data rates and data rates can even vary in time. UMTS networks need to support all current second generation services and numerous new applications and services.

FDD Technical summary

Frequency band:1920 MHz -1980 MHz and 2110 MHz – 2170 MHz (Frequency Division Duplex) UL and DL [more]
Minimum frequency band required: ~ 2x5MHz
Frequency re-use: 1
Carrier Spacing: 4.4MHz – 5.2 MHz
Maximum number of (voice) channels on 2x5MHz: ~196 (spreading factor 256 UL, AMR 7.95kbps) / ~98 (spreading factor 128 UL, AMR 12.2kbps)
Voice coding: AMR codecs (4.75 kHz – 12.2 kHz, GSM EFR=12.2 kHz) and SID (1.8 kHz)
Channel coding: Convolutional coding, Turbo code for high rate data
Duplexer needed (190MHz separation), Asymmetric connection supported
Tx/Rx isolation: MS: 55dB, BS: 80dB
Receiver: Rake
Receiver sensitivity: Node B: -121dBm, Mobile -117dBm at BER of 10-3
Data type: Packet and circuit switch
Modulation: QPSK
Pulse shaping: Root raised cosine, roll-off = 0.22
Chip rate: 3.84 Mcps
Channel raster: 200 kHz
Maximum user data rate (Physical channel): ~ 2.3Mbps (spreading factor 4, parallel codes (3 DL / 6 UL), 1/2 rate coding), but interference limited.
Maximum user data rate (Offered): 384 kbps (year 2002), higher rates ( ~ 2 Mbps) in the near future. HSPDA will offer data speeds up to 8-10 Mbps (and 20 Mbps for MIMO systems)
Channel bit rate: 5.76Mbps
Frame length: 10ms (38400 chips)
Number of slots / frame: 15
Number of chips / slot: 2560 chips
Handovers: Soft, Softer, (interfrequency: Hard)
Power control period: Time slot = 1500 Hz rate
Power control step size: 0.5, 1, 1.5 and 2 dB (Variable)
Power control range: UL 80dB, DL 30dB
Mobile peak power: Power class 1: +33 dBm (+1dB/-3dB) = 2W; class 2 +27 dBm, class 3 +24 dBm, class 4 +21 dBm
Number of unique base station identification codes: 512 / frequency
Physical layer spreading factors: 4 … 256 UL, 4 … 512 DL

Iklan
Oleh: volcanon88 | Maret 26, 2009

Oscar Wilde Biography

oscar-wilde

Oscar Fingal O’Flahertie Wills Wilde was born on October 16, 1854 at 21 Westland Row, Dublin, Ireland. Wilde’s father, William Wilde, was Ireland’s leading ear and eye surgeon at Dublin Eye and Ear Hospital and author of books on archaeology and folklore as well as the husband to a successful Irish nationalist writer, Jane.

In June 1855, the Wilde’s moved to 1 Merrion Square. There, Jane Wilde held many sessions with guests including Samuel Ferguson, George Petrie amongst many other figures.

Until the age of nine, Oscar Wilde received his education from home. After, Wilde attended Portora Royal School in Enniskillen, Fermanagh until 1871. After leaving Portora, Wilde continued his studies at Trinity College, Dublin for the next three years. Wilde was an excellent student receiving the highest award, Berkeley Gold Medal and then receiving a scholarship to Magdalen College, Oxford where he would study from 1874 to 1878. At Magdalen he did much the same, winning the 1878 Oxford Newdigate Prize for his poem Ravenna. Wilde graduated with a double first.

After graduation, Wilde fell in love with Miss Florence Balcome. However, their relationship failed as she became engaged to Bram Stoker. After hearing of her engagement, Wilde wrote Miss Balcome and proclaimed to leave Ireland permanently. His next six years were spent in London, Paris and the United States only to return to his home country twice for brief visits.

During Wilde’s stint in London, he met the daughter of a wealthy QC, Constance Lloyd and began courting her. She visited Dublin in 1884 when Wilde was giving lectures at the Gaiety Theatre. He proposed to her and they later married on May 29, 1884 in Paddington, London. With Constance’s allowance of £250, the two lived in relative luxury.

The couple had two sons, Cyril in 1885 and Vyvyan in 1886. After Wilde’s imprisonment for gross indecency and sentenced to two years of hard labor on May 25, 1895, Constance changed her and her sons names to Holland. She died in 1898 following a spinal surgery and was then buried in Staglieno Cemetary in Genoa, Italy.

Wilde’s first born, Cyril was killed in France during WWI. However, Vyvyan became an author and translator later in life, his memoir was published in 1954.

After Wilde’s release from prison on May 19, 1897, he spent the following years penniless. He took the pen-name Sebastian Melmoth, the central character of Melmoth the Wanderer, and wrote one of his finest works, The Ballad of Reading Gaol.

Wilde’s last days were spent converting to the Roman Catholic church, which he long admired, at the Hotel d’Alsace in Paris. His last words are reportedly “My wallpaper and I are fighting a duel to the death. One or the other of us has got to go.”

Oscar Wilde died on November 30, 1900 due to cerebral meningitis. Wilde was buried at the Cimetière de Bagneux outside Paris but was later moved to Le Père Lachaise Cemetery in Paris. His tomb was designed by the famous sculpor Sir Jacob Epstein.

Oleh: volcanon88 | Maret 26, 2009

Anecdote For Fathers

William Wordsworth

I have a boy of five years old;
His face is fair and fresh to see;
His limbs are cast in beauty's mold
And dearly he loves me.

One morn we strolled on our dry walk,
Or quiet home all full in view,
And held such intermitted talk
As we are wont to do.

My thoughts on former pleasures ran;
I thought of Kilve's delightful shore,
Our pleasant home when spring began,
A long, long year before.

A day it was when I could bear
Some fond regrets to entertain;
With so much happiness to spare,
I could not feel a pain.

The green earth echoed to the feet
Of lambs that bounded through the glade,
From shade to sunshine, and as fleet
From sunshine back to shade.

Birds warbled round me---and each trace
Of inward sadness had its charm;
Kilve, thought I, was a favoured place,
And so is Liswyn farm.

My boy beside me tripped, so slim
And graceful in his rustic dress!
And, as we talked, I questioned him,
In very idleness.

"Now tell me, had you rather be,"
I said. and took him by the arm,
"On Kilve's smooth shore, by the green sea,
Or here at Liswyn farm?"

In careless mood he looked at me,
While still I held him by the arm,
And said, "At Kilve I'd rather be
Than here at Liswyn farm."

"Now, little Edward, say why so:
My little Edward, tell me why."---
"I cannot tell, I do not know."---
"Why, this is strange," said I;

"For, here are woods, hills smooth and warm:
There surely must one reason be
Why you would change sweet Liswyn farm
For Kilve by the green sea."

At this, my boy hung down his head,
He blushed with shame, nor made reply;
And three times to the child I said,
"Why, :Edward, tell me why?"

His head he raised---there was in sight,
It caught his eye, he saw it plain---
Upon the house-top, glittering bright,
A broad and gilded vane.

Then did the boy his tongue unlock,
And eased his mind with this reply:
"At Kilve there was no weather-cock;
And that's the reaon why."

O dearest, dearest boy! my heart
For better lore would seldom yearn,
Could I but teach the hundredth part
Of what from thee I learn.

Oleh: volcanon88 | Maret 26, 2009

Look, It Cannot be Seen

Lao Tzu

Look, it cannot be seen - it is beyond form.
Listen, it cannot be heard - it is beyond sound.
Grasp, it cannot be held - it is intangible.
These three are indefinable, they are one.

From above it is not bright;
From below it is not dark:
Unbroken thread beyond description.
It returns to nothingness.
Form of the formless,
Image of the imageless,
It is called indefinable and beyond imagination.

Stand before it - there is no beginning.
Follow it and there is no end.
Stay with the Tao, Move with the present.

Knowing the ancient beginning is the essence of Tao.
Oleh: volcanon88 | Maret 26, 2009

Albert Einstein’s Wise Words

“A human being is part of the whole, called by us the ‘universe’, a part limited in time and space. He experiences himself, his thoughts and feelings, as something separate from the rest -a kind of optical delusion of consciousness. This delusion is a kind of prison for us, restricting us to our personal desires and to affection for a few persons nearest to us. Our task must be to free ourselves from this prison by widening our circle of compassion to embrace all living creatures and the whole of nature in its beauty.”

“It has become appallingly obvious that our technology has exceeded our humanity.”

“With all my heart I believe the present system of sovereign nations can lead only to war, barbarism, inhumanity, and only through world law can we assure progress toward civilization.”

” The ideals that lighted my way, and time after time have given me new courage to face life cheerfully have been Kindness, Beauty and Truth.”

Oleh: volcanon88 | Maret 26, 2009

Types of CDMA

1. Frequency-Hopping
• Each user’s narrowband signal hops among discrete frequencies, and the receiver follows in sequence
• Frequency-Hopping Spread Spectrum (FHSS) CDMA is NOT currently used in wireless systems, although used by the military

2. Direct Sequence
• narrowband input from a user is coded (“spread”) by a user-unique broadband code, then transmitted
• broadband signal is received; receiver knows, applies user’s code, recovers users’ data
• Direct Sequence Spread Spectrum (DSSS) CDMA IS the method used in IS-95 commercial systems

Oleh: volcanon88 | Maret 26, 2009

Introduction to OFDM

l. Basic idea
» Using a large number of parallel narrow-band subcarriers instead of a single wide-band carrier to transport information
2. Advantages
» Very easy and efficient in dealing with multi-path
» Robust again narrow-band interference
3. Disadvantages
» Sensitive to frequency offset and phase noise
» Peak-to-average problem reduces the power efficiency of RF amplifier at the transmitter
4. Adopted for various standards
– DSL, 802.11a, DAB, DVB

2

Oleh: volcanon88 | Maret 26, 2009

CDMA Technology Evolution

untitled2

Oleh: volcanon88 | Maret 25, 2009

10 Simple Ways To Overcome Depression and Sadness

  1. Set Goals
    Something special happens the moment the paper meets the pen and we write down our goals. Our brain chemistry changes, neurons fire, hormones are deployed, and we start thinking about how we can achieve those goals.
  2. Sleep
    Getting the right amount of sleep is healthy for our body and mind. Some argue that sleep deprivation treats depression, but I don’t buy it. I think it’s a cheap distraction that catches up to you within days. Get enough rest.
  3. Exercise
    If you’re physically capable, try one hour of cardio (or as much as you can). If you’re tee-shirt is soaking wet, you’re standing in a puddle of your own sweat, and you can feel the endorphins pumping through your body, you did it right. Shower up and try not being happy, I dare you.
  4. Forgiveness
    Many times we’re making ourselves sad for no good reason at all. People have been known to keep grudges for lifetimes (most religions and nationalities keep them for generations). When you forgive, you remove this weight off your shoulders and put yourself in a position to be happier.
  5. Gratitude
    Many times when we complain we can cause ourselves to be sad. Complaining is just a factor of not taking into account what we’re grateful for. Sit down and make a list of 100 things you’re grateful for right now (and I dare you not to feel better).
  6. Sunlight
    Certain people have a disorder, in which, due to a lack of sunlight, they experience seasonal sadness. I’m somewhat affected by this in the winter when the days are shorter. That’s why it pays to grab your iPod (or your friend) and go for 30 minute walks each day and embrace the sunlight.
  7. Hydration
    This has always been my downfall; I don’t drink enough and chances are you don’t either. Some days I drink only 1 cup of water, and I feel horrible. When I remember, and drink 2-3 liters, I’m happy as a kitten on cat-nip, and productive as a bat out of hell.
  8. Friendships
    Your life force, support system, and everything that matters. It’s not hard to make friends if you put the time in. Everyone wants to be heard, appreciated, and loved. Start off by listening, appreciating and loving, and it will come back your way.
  9. Reading
    Take a temporary leave from reality and bury yourself in one of your favorite books. A lot of wise people have been through what you’re going through and they made it through to the other side to tell about it.
  10. Journal
    This could be an escape but it doesn’t have to be. You can write about fiction, and transport yourself to another world, or you can write about what’s going on, and let your thoughts carry you through to a solution. Many great books were written by people who were, at least at the time, going through a period of pain and suffering.
Oleh: volcanon88 | Maret 25, 2009

Life is Beautiful..

The most beautiful future will always depend on the need for forgetting the past.
You will not be able to go from the past in life as long as you will not have overcome
the errors of the past and all that hurt you.

life-is-beautiful

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