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Doppler Effect In Ofdm

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1000 Threads found on Doppler Effect In Ofdm
Does doppler effect change the amplitude?doppler effect no, fading generator yes. Basic doppler effect involves a time-variant phase shift and no amplitude variation. But the said fading generator (I don't know the specific MATLAB implementation) superimposes multiple channels.
hi in wireless communication when T > T_D doppler effect leads fast fading, where T is symbol duration and coherence time is T_c = 1/f_D. f_D has the maximum value of 300 Hz, so T_c has the minimum of 3 ms. so doppler phenomena only affects systems with symbol rate below 300 sym/sec. thus in real wireless communication (...)
Everywhere I see that CP can overcome the ISI and ICI in ofdm, and only when CP is longer than channel length, it can convert linear convolution to circular convolution. However, what if CP is shorter than channel length? Could you please explain that in math? And how to deduce its effect in matrix? thanks very much for any explanation!
How can I use doppler signal in my M_File in MATLAB?Is there a function or command for it? I'm not good in MATLAB!please help me.
hi , frequency offsets are due to channel delay spread (coz of channel impairments ) and doppler spread ( movin vehicles) suppose ur upconvertin RF frquency is @ 2 Ghz and IF :100 MHZ , ur transmitting frequency will be 2100 MHZ so if ur channel delay spread is say 10 HZ ur recieved signal at RX will be 2100. 000 010 hz , ur receiver d
frequency offset (FO) occurred by the mismatch between the oscillators in the transmitter and receiver or doppler frequency and it can cause performance degradation or we can say it can increase BER
Hello, I am looking for a MATLAB code for ofdm that introduces doppler effect due to relative motion of Tx/Rx. Thanks in advance
hi see the links below i hope it may help
Hi everyone I'm new here and I need some help from u. I have to make a matlab program in order to draw the IQ diagram for some signals as BPSK and QPSK. I have to correct the doppler effect and the phase shift with PLLs. I think Costas loops are good for correcting the phase shift. But what about the doppler effect ? (...)
Hi everyone I think I've post in the wrong forum yesterday, so here is my problem. I have to make a matlab program in order to draw the IQ diagram for some signals as BPSK and QPSK. I have to correct the doppler effect and the phase shift with PLLs. I think Costas loops are good for correcting the phase shift. But what about the (...)
in general: A preamble is used in Digital Communication Systems to train the VCO of the receiver to the incoming signals's clock so as to produce a clocking in the reciver that is synchronized to the received signal, and so a perfect sampling and/or demodulation can be done. Secondly: The pilot symbols are used in wireless communication systems fo
Hi, Can somebody help me? For my project, I have to simulate a doppler radar with matlab. Do someone have an idea about the code? And do someone have an idea about how to compute a correlation function with Matlab? THANKS a lot for your help.
Do someone know how to compute the doppler effect with matlab? thanks a lot
Hi. I have a problem understanding the circuit I have attached. As i understand, the signal that is received (in sinusodial form) is being "converted" to a pulse length depending on the incoming signal's frequency. Am I right on this? Can anyone explain me maybe in more detail about what is really going on. Would appreciate it lot. The circui
In ofdm system, why do we need Equilizer?
Hi,QMA 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
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
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 domain point?
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
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. :?: Thanks!
Hello friends, 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). Thanks
Hi, 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.)?
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. Regards Z
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. :?: Thank you,..
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
Hi, 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
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?
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.
Q1: 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
Hi, 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 (...)
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
likewise threshold effect in Fm there any threshold effect in AM
hi all How to use a resistance with it's noise effect in orcad thx
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?
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
Hai, 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 - matt
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..
hi, can some body tell me how to code BER in ofdm using 64qam in matlab. sim.
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
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?
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 thanks santosh
Hi 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? Thanks.
what is DIBL effect in mosfet,please explane this
plz , send a BER equations for different mod in ofdm, IF u don't mind.
HOW TO GENERATE SUBCARRIERS in ofdm ? i am using matlab 6.5 ver
hi guys if i connect the poly as follows m4>m3>m2>m1>poly is this will cause antenna problem if it occures how can i avoid it regards analayout
Can Anyone help me in understanding the ringing effect in the power analysis/calculations.
how can one tackle body effect in a circuit ?????????
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: 1-exp(-S*Tref) ———————— S*Tref practical calculation reveal that : when bandwidth >20*reference frequency, phase drif
What type of interference is there in ofdm (if any)? Is it cochannel interference or subchannel interference?