on what basis the fft length is calculated related to the sampling frequency?I want to search for a maximum peak by obtaining the spectrum of the...

on what basis the fft length is calculated related to the sampling frequency?I want to search for a maximum peak by obtaining the spectrum of the signal.I am working on demodulator in that my task is to acquire the carrier from the receive modulated signal.Modulation used is BPSK.It can be used for 300,600,1200,2400,10800,5400 bit rates.sampling frequency is 518400 for 10800 and 5400 bit rates,for...

on what basis the fft length is calculated related to the sampling frequency?I want to search for a maximum peak by obtaining the...

on what basis the fft length is calculated related to the sampling frequency?I want to search for a maximum peak by obtaining the spectrum of the signal.I am working on demodulator in that my task is to acquire the carrier from the receive modulated signal.Modulation used is BPSK.It can be used for 300,600,1200,2400,10800,5400 bit rates.sampling frequency is 518400 for 10800 and 5400 bit rate...

Suppose I take samples at once per minute for a data logger. Do I still need an anti-aliasing filter? The sampling freq would be 1/T where T=60...

Suppose I take samples at once per minute for a data logger. Do I still need an anti-aliasing filter? The sampling freq would be 1/T where T=60 secs...so how is this possible? The values of the capacitors etc would be hugh. Of course I could over-sample1000s of times...is this the norm? K.

I recently started simulating a HiperMAN/WiMAX PHY on MATLAB. However, in the standard available in the ETSI website, there is mention of a...

I recently started simulating a HiperMAN/WiMAX PHY on MATLAB. However, in the standard available in the ETSI website, there is mention of a "sampling frequency" and a term "bandwidth over sampling frequency". I haven't a clue as to what these terms mean and where they're used in the OFDM process. Could somebody shed some light on what these terms mean in the context of OFDM? Thanks Neelabh...

Dear all, I have to develop an application with the following basic requirements: - 40 analog channels of Voltage/Current - ADC with 16 bits...

Dear all, I have to develop an application with the following basic requirements: - 40 analog channels of Voltage/Current - ADC with 16 bits of resolution - at least 96 sample point per cycle (50 and 60Hz), which means 4800 and 5760Hz of sampling frequency - simultaneous sampling of all channels The main concern is data acquisition. It is a like a data logger. Since a lot of mat...

Hi, Does anyone know if there is a program out there that can change digital data in the form of binary files back into analog to resample it...

Hi, Does anyone know if there is a program out there that can change digital data in the form of binary files back into analog to resample it to a different sampling rate? I guess, the whole point of this is to get a different sampling rate. Is it possible? Seems pretty unheard of to change it back to analog.. :X Thanks!

Hello, I have an ENG signal, sampled at 25kHz that has high mains interference that I want to remove. The problem is I need the surrounding...

Hello, I have an ENG signal, sampled at 25kHz that has high mains interference that I want to remove. The problem is I need the surrounding frequencies, maybe not 50-70, but I can't afford to sacrifice much more than this. The filter designs I've been looking at don't seem to be able to do this at such a high sampling rate. Any suggestions? Would downsampling help? Thank you in adva...

The sampling theorem tells us that we must sample at least twice the bandwidth of a signal. When the signal is centered around dc to some max...

The sampling theorem tells us that we must sample at least twice the bandwidth of a signal. When the signal is centered around dc to some max freq say Fmax than we can say Fs> =2Fmax. However, when the signal is centred around some other higher frequency (say Fc), how is bandwidth defined? is it from Fc (the center freq) to the max value or from Fc-minfreq to Fc + maxfreq ? If you apply te

I am sampling voltage values. I need to convert it to the frequency domain using FFT . As I understand the frequency steps after FFT will be the...

I am sampling voltage values. I need to convert it to the frequency domain using FFT . As I understand the frequency steps after FFT will be the integer multiples of Fs/N (where Fs is the data sample rate in Hz, and N is the FFT length). How can I have sub-Hz frequency steps? Do I use use long sampling times and long FFT lengths, for instance, Sampleing at 1 kHz and using 10000 FFT length will...

Hi all... I am pretty new to signal processing... Let say we sample a band limited signal... So the spectrum of the sampled signal...

Hi all... I am pretty new to signal processing... Let say we sample a band limited signal... So the spectrum of the sampled signal will have spectral replications of the band limited signal and multiples of the Sampling frequency... So in this case the resulting signal seems to have more energy... since its spectrum is large compared to the bandpass signal and the sa...

I am having a little trouble with getting a clear picture of extracting what frequencies are represented in an input stream from the...

I am having a little trouble with getting a clear picture of extracting what frequencies are represented in an input stream from the DFT. Here's my current picture -- 1) Given N=16384 samples at a sampling rate of 5 secs or 0.25 Hz 2) 16384 samples = 81920 secs = 1365.3 min = 22.76 hrs 3) Each frequency sample of the DFT, Xk = c_k / N, the spectral coefficient in the discrete time f...

Hello All Our application is channel embed/de-embedding. The frequency characteristics of the channel are specified in a ...

Hello All Our application is channel embed/de-embedding. The frequency characteristics of the channel are specified in a (S-parameters file). To generate an FIR filter, matching the specified frequency response, Frequecny sampling method using IFFT is used. We have been able to use this with limited success. I am looking for the limitation's of this IFFT method - ...

Hello everyone, I am new to dsp and working on a project where I need to take 1000 8-bit samples per second. Each sample will be at 1 of 11...

Hello everyone, I am new to dsp and working on a project where I need to take 1000 8-bit samples per second. Each sample will be at 1 of 11 predefined frequencies. My question is, is it possible to detect frequencies at a sampling rate of 1 per millisecond. (1000 samples per second). I would like to use a computer to do this rather than any hardware. Any help would be greatly appreciate...

Hello, I am pretty confused with some DFT/Sampling techniques and how these apply to OFDM. Fundamentally, if a (baseband) signal has a...

Hello, I am pretty confused with some DFT/Sampling techniques and how these apply to OFDM. Fundamentally, if a (baseband) signal has a highest frequency component of f Hz, that signal needs to be sampled at 2f Hz for aliasing-free data reconstruction. My confusion begins with OFDM, which does the process in reverse. That is IDFT is performed first. So, in OFDM, the output of the IDFT blo...

I have made a simulation of ofdm on baseband and it works fine. to simulate the sampling clock synchronization problem, i have resampled the...

I have made a simulation of ofdm on baseband and it works fine. to simulate the sampling clock synchronization problem, i have resampled the baseband waveform using resample function in MATLAB. yt = resample(yt, 1601, 1600); Now, even with such a small offset, my receiver does not work (yt contains 1600 samples comprising 20 ofdm symbols each of 64 point + 16 cyclic prefix = 80 samples). M...

Hi All I have a carrier modulated signal which is sampled at 48KHz and 12 samples/symbol. Now, I want to resample this signal, so that the...

Hi All I have a carrier modulated signal which is sampled at 48KHz and 12 samples/symbol. Now, I want to resample this signal, so that the new signal has sampling rate of 47968 Hz. Is there any possible way of doing it.? I totally new to this multirate dsp topic. Your opinion matters a lot. Thanks. Chintan

I have a basic question here regarding OFDM digital front end. if i have a very efficient clock of say 10ppm, can i downsample the signal to the...

I have a basic question here regarding OFDM digital front end. if i have a very efficient clock of say 10ppm, can i downsample the signal to the sampling frequency of transmitter. i.e. the sampling frequency at which i will get 64 samples for a 64 sample FFT block? for example, the FFT output at the transmitter is at 500 kHz. Now can i directly down sample this signal to 500 kHz baseband sign...

Hi, I am trying to extract MFCC coefficients for variable sample rate audio feed 1.Input Sample rate is dynamic and is not known in front (...

Hi, I am trying to extract MFCC coefficients for variable sample rate audio feed 1.Input Sample rate is dynamic and is not known in front ( an arbitrary media file ) though it is fixed per session and doesn’t change over time. 2.All Input feeds are being down sampled to a predefined sampling-rate ( say 8Khz or 16Khz ) 3.Re-sampling is done in the following way: a.2nd order Lowpass

Hi everyone For a mini project I am doing, I want to generate Doppler coefficients for Jakes model. But I want to do this with varying sampling...

Hi everyone For a mini project I am doing, I want to generate Doppler coefficients for Jakes model. But I want to do this with varying sampling rates, i.e. generate at twice the maximum Doppler frequency in 1st iteration and then at 5 times the maximum Doppler in the 2nd iteration etc. I read the book "Mobile fading Channels by Matthuas Patzold", but in the methods he has given I could not fin...

Is there really such a thing as a First Order Hold as you see in some textbooks? I have looked many times at DAC outputs and all I see are...

Is there really such a thing as a First Order Hold as you see in some textbooks? I have looked many times at DAC outputs and all I see are staircase type waveforms ie Zero-Order Holds. Also, with a high sampling rate the effect of the ZOH more or less vanishes - do we need to still analyse it? There is a phase shift of course which is important (-90 degrees at half sampling but this gets sma...