From the Rx side, assume perfect operation
(1) is the position of time index start for DFT window process of N point (only useful data length) mean as find the first edge of each symbol or some point between channel length
Digital communication :: 04-12-2007 10:26 :: maomun :: Replies: 1 :: Views: 1166
hi udit .. my MS thesis was in channel estimation for ofdm transmission in fast fading doppler channels so that would be phy layer. righ now I am inclined towards getting to know WiMax so want to focus more on mac layer, though interesting ideas in phy are still welcome
Digital communication :: 05-01-2007 12:44 :: goosecool :: Replies: 8 :: Views: 2487
the inputting of the IFFT in ofdm should be the frequency domain point. which is the mapping of the constellation such as QAM or QPSK. but the vector in the consellation is just complex.why some book call this vector frequency domain point? such as 3-3j in conselation,it shoud be time domain signal,why is frequency
Digital communication :: 06-24-2008 11:26 :: richardhuang :: Replies: 4 :: Views: 1745
From several references, I read that SCO (Sampling Clock Offset) cause linearly increasing phase in frequency domain, such as stated in:
Simulation of Sampling Clock Offset | Comp.DSP |
I tried to create matlab cod
Digital communication :: 09-22-2010 01:22 :: flyingdot :: Replies: 0 :: Views: 2369
Hi! Can somebody help me!
I am learning about doppler effect, but i do not understand the doppler effect on the land and underwater is the same or different? Suppose that i want to using the doppler effect to estimate the velocity of an object such as car and submarine. :?:
Digital communication :: 11-10-2011 02:31 :: ducvilla :: Replies: 6 :: Views: 428
Does the synchronization techniques for timing and frequency offset effect SNR in ofdm? ex. higher by 3 dB or the same , or it varies
Synchronization by using (Delay,Conjugate , multiply ) and integate over TG(Gaurd interval).
Digital communication :: 12-17-2011 03:26 :: ReComm :: Replies: 0 :: Views: 327
I need to apply the doppler effect to a music file, I invoke the music file by using the waveread command,
How do I proceed next (frequency spectrum, apparent frequency etc.)?
Digital Signal Processing :: 04-10-2012 02:04 :: Rahp :: Replies: 2 :: Views: 2018
The two effects have in common that they can alter the apparent frequency of a signal, but their origins are completely different. As Frank said, doppler comes from relative movement, and aliasing comes from sampling.
Electronic Elementary Questions :: 03-18-2014 16:40 :: zorro :: Replies: 2 :: Views: 491
Is spectral frequencies related to doppler effect shift.For example. the doppler shift effect will be positive if the recever (mobile phone) is moving towards to the base station. :?:
RF, Microwave, Antennas and Optics :: 07-13-2004 23:28 :: roustabout :: Replies: 0 :: Views: 662
Hi! I know that aircraft navigation is based on DME equipments which provide a measure of distance and VOR equipments which provide a measure of angle. DME measure is done by measuring the time distance between pulses generated by aircraft and echoed by DME.
I've heard that the measure of the angle is achieved by doppler effect of RF signal gener
RF, Microwave, Antennas and Optics :: 08-04-2004 04:16 :: a_fischetti :: Replies: 2 :: Views: 1304
How can I create an 'explosion' effect, in an electronic circuit? Soemthing like I press a button and it produces atleast something like a spark
Electronic Elementary Questions :: 06-24-2005 12:09 :: irfanhab :: Replies: 9 :: Views: 1037
Elementary questions, hope u guys dun mind..
I often see 1024 point or 1024 bin length FFT & IFFT for ofdm. At first i thought 1024 represents the number of subcarriers for ofdm, but i later realized it wasn't. So what does 1024 represents?
And what is the relationship between the point number/bin lenght and the number of subcarriers?
Digital Signal Processing :: 07-25-2005 08:39 :: Antonio_Magma :: Replies: 11 :: Views: 18107
I would like to know about cyclix prefix in ofdm.I have heard that cyclic prefix is added inorder to avoid inter carrier interference.will addition of this cyclix prefix result in frequency shift.Why don't we zero pad instead of using this cyclic prefix.
Digital Signal Processing :: 08-27-2005 02:45 :: udit :: Replies: 1 :: Views: 978
This is with reference to the white paper by TI entitled, "Power Line Modem with E-meter Platform", 2004 (i'm sorry i can't find the link to the article)
At the part where the paper decribes the Packet Format for the ofdm frames. It says that the data frames are grouped into blocks of 3 frames and each data frame in the block contains ident
Digital Signal Processing :: 11-17-2005 21:50 :: Antonio_Magma :: Replies: 3 :: Views: 1040
I wanted to generate tone in an already built ofdm transmitter model. I want to send one tone of like 3Ghz and receive it on receiver. The problem is i am not very much familiar with ofdm transmission and secondly I think Pilot tones before IFFT make more tones than expected in baseband.
My question is can I send one tone in ofdm (...)
RF, Microwave, Antennas and Optics :: 11-22-2005 10:53 :: Usman Hai :: Replies: 7 :: Views: 1522
how to mitigate body effect in BJT ...normally by keeping low reverse voltage to collector base junction we can avoid it.. is there any other soultion in sight to mitigate it
Electronic Elementary Questions :: 12-28-2005 02:32 :: electronics_kumar :: Replies: 3 :: Views: 1344
likewise threshold effect in Fm there any threshold effect in AM
Electronic Elementary Questions :: 01-01-2006 05:21 :: electronics_kumar :: Replies: 1 :: Views: 1757
How to use a resistance with it's noise effect in orcad
Software Problems, Hints and Reviews :: 03-08-2006 05:46 :: agana56 :: Replies: 1 :: Views: 526
Everywhere I read they talk about the head of a symbol being affected by previous symbol, and so how cyclic prefix takes care of that.How bout the tails of the symbols-won't they be affected equally due to future symbols.How is that taken care of?
Digital communication :: 03-09-2006 09:26 :: Sur :: Replies: 5 :: Views: 1907
hi this is narender,
can anyone tell me, how to produce echo and reverb effect in audio sounds. i have a small duration sound, i need to lengthen the duration with slowlyu decreasing sound. can anyone tellme how to do this in the most simple way. how can this be donw using analog electroncis. analog ic's, websites, links, circuits, schematics et
Analog Circuit Design :: 04-18-2006 01:45 :: dnarenderreddy :: Replies: 4 :: Views: 2625
I am new to ofdm...was reading up a few articles on ofdm and came across cyclic prefix quite frequently..Can someone please explain what this is and why it is used..?? Or can someone provide me some material which explain the same...
thanks in advance
Digital communication :: 05-26-2006 07:24 :: mathew.paul :: Replies: 6 :: Views: 13389
Hi to all,
I am currently working on a circuit design that requires me to consider the body effect in NMOS.. could anyone clarify what this effect is exactly??
Also, what steps can be taken to avoid this effect ?? I want to tackle body effect as it is reducing the output voltage value in our design..
Analog IC Design and Layout :: 06-24-2006 04:28 :: sbhalerao :: Replies: 11 :: Views: 5699
can some body tell me how to code BER in ofdm using 64qam in matlab.
Digital communication :: 07-26-2006 07:22 :: SIMHA :: Replies: 1 :: Views: 1832
Please can anyone tell me what does SVD function in MATLAB do to a rayleigh frequency selective fading channel.
In ofdm simulation, the magnitude response is passed on to the svd function and it returns the matrix 'S' which is used further in the simulation...
Can anyone please tell me the usage of this svd in ofdm simulation???
Does this gi
Digital communication :: 08-24-2006 02:39 :: xischaune :: Replies: 0 :: Views: 971
what is the need of IFFT and FFT in ofdm?
what is cyclic prefix?
what is out of band energy in ofdm transmitters ?how it will happen?
Digital communication :: 09-08-2006 11:04 :: raghavenderece :: Replies: 3 :: Views: 3813
can any one have idea on synchronisation in ofdm system pls help me
if any one knows details abt this and any links available for this plss tell me
Digital Signal Processing :: 10-11-2006 11:42 :: akskumar12 :: Replies: 0 :: Views: 515
I want to ask you about EM effect in space.
For example we exploit a nuclear bomb both in space and in world(atmospheric environment).
Which one is spread more effect than other.
I mean does EM radiation dependt on environment?
Which formula shows us this dependency?
Mathematics and Physics :: 11-27-2006 06:41 :: serimc :: Replies: 2 :: Views: 695
what is DIBL effect in mosfet,please explane this
ASIC Design Methodologies and Tools (Digital) :: 12-30-2006 11:30 :: nandakishoryadav :: Replies: 5 :: Views: 1383
plz , send a BER equations for different mod in ofdm, IF u don't mind.
Digital communication :: 01-22-2007 16:04 :: ridamoha :: Replies: 4 :: Views: 3302
HOW TO GENERATE SUBCARRIERS in ofdm ?
i am using matlab 6.5 ver
Digital communication :: 02-07-2007 02:46 :: venkateshkumar :: Replies: 5 :: Views: 2401
if i connect the poly as follows
is this will cause antenna problem
if it occures how can i avoid it
Analog IC Design and Layout :: 03-05-2007 01:00 :: analayout :: Replies: 10 :: Views: 1405
Can Anyone help me in understanding the ringing effect in the power analysis/calculations.
ASIC Design Methodologies and Tools (Digital) :: 03-08-2007 08:37 :: nanda_kishore :: Replies: 2 :: Views: 4164
how can one tackle body effect in a circuit ?????????
Analog Circuit Design :: 03-13-2007 12:34 :: engrvip :: Replies: 10 :: Views: 1086
when pll bandwidth close to reference frequency,
ZOH(Zero order holding ) effect in PFD must be considered, which bring phase drift in the loop transfer function:
practical calculation reveal that :
when bandwidth >20*reference frequency, phase drif
Analog Circuit Design :: 07-07-2007 03:17 :: alpacinoliu :: Replies: 0 :: Views: 459
What type of interference is there in ofdm (if any)? Is it cochannel interference or subchannel interference?
Digital communication :: 08-13-2007 16:06 :: pmonon :: Replies: 3 :: Views: 859