Thursday, December 4, 2008
today went sch for a 2 hr de pdpr, nv do any soildering..learn only kmap.Then actually wan to go for dcnt tut de but got to wait for 5 hrs.Wat can i do in 5hr de break in sch?study meh? hahaha..i wont de lor.. with weeli n i, we will just talk non stop n can just forget abt studying.Anyway instead of studying or go for a 5hrs break we 4 went to kfc ad have our lunch.Actually everything was so fine de,BUT ttk la..anyhow talk then weeli angry le.So after that i went studying with wt..LOLS.we end up talking for hrs instead of studying.But i promise that i come home will study my dcnt de..cos tml got test then somemore next thurs will have a coomon test.Sick man.Y must we go for common test?go sch jiu ok le mah..y test n exam.make us so stress.okok..below are some real boring stuff abt wat i am studying.DCNT!
Speed of data transmission is base on
1:available bndwidth of the transmission medium
2:quality of tranmission medium(level of noise)
3:levels of signal to be transmitted.
Nyquist rate=2fmax
Bit RATE = 2 * max transmission freq * number of bits
Guided transmission media=
Optical fibre( among the 3 tis is the best it have fastest bit rate thus it have the largers bandwidth.)
=
Twisted wires =Coaxial cables.HDB3 is not a Polar line coding scheme.
RS-232 is a standard that applies to serial ports.
Data communication uses parity bit becos it can act as an error checking mechanism.
bandwidth= higher freq-lower freq
pulse modulation signal:(got3)
PAM= PULSE AMPLITUDE MODULATION
PWM= PULSE WIDTH MODULATION
PPM=PULSE POSITION MODULATION
Digital modulation methods:
DM=DELTA MODULATION
PCM=PULSE CODE
(got tis wrong during practise)CT mustget it right!!
The sequence of PCM IS: bandlimiting
sampling
quantiziling
ecoding.
Simplex: data tranmission is alway undirectional.receive only
eg: printer
half deplux:both direction but nt the sametime.eg:web document.
full deplux:same time same direction.eg: telephone
effective data communincation:
1-delivery
2-accuary
3-timeliness
hahha i guess tis is wat i all know abt dcnt..guess im gg to fail my test tml..lols
Labels: common test, DCNT, DM, exam, kfc, PAM, PCM., PPM, PWM, ttk, weeli, wt
9:47 PM
Sunday, November 9, 2008
is my day! haha.. thanks you to all..esp angela,anthony, teo didi(haha),yong jie, weeli, ttk n.....wt. lol. thanks for all of the things u all plan.So touch.Really.im falling in love with all of u.hahha..will upload the pic once it is ready.jacjac dear thanks for the bdae present and thanks for everything.hee.Im so happy to have so many friends around mii.Thank you.WT thanks you for all tat u have plan today.Love yr flower the most n yr card is some sweet.Thanks you.Im so xin fu.I love my 2 sis too.Thanks you thank you.. Lots of present from my 2 sis.They love mii lots.Im really dote by all of u all.Hee.Even thought today is 6 month past of a bad day but i think im getting very clear of wat i wan now.I know who is the one who will be the one who treat mii gd n who take care for mii.So now, i have grown up.Hahaha..Im happy n i know things that have past are all past tense they wouldnt b back.Now im totally clear of wat im doing.Hee..
Labels: angela, anotony, my birthday, shawn, thank you., weeli, weiting, yong jie
10:10 PM
