Hi all !!! I am newbie to signal processing and I have to make QPSK modem. Here are some basic parameters of this system: - sampling frequency...

Hi all !!! I am newbie to signal processing and I have to make QPSK modem. Here are some basic parameters of this system: - sampling frequency 18.5kHz - carrier frequency 1.85kHz; carrier is synchronous with sampling frequency - symbol rate 1.85kS/s; every symbol starts with the same carrier phase - I/Q are shaped in baseband using 41tap FIR root rised cosine filter (4 symbols involved: 2...

I was introduced to this book in comp.dsp so i assumed there r ppl here who are familiar with this book. I have a question from this book. It...

I was introduced to this book in comp.dsp so i assumed there r ppl here who are familiar with this book. I have a question from this book. It is from Chapter2: Periodic Sampling section2.3 Bandpass sampling, equation 2-10: (2Fc-B)/m > = Fs > = (2Fc+B)/(m+1) What is this 'm'? I can't find its definition, can someone tell me where can i find it in the book or tell me its definition? Thx

I have a question about PLESIOCHROUNOUS re-sampling of audio. It was mentioned in another thread that simply deleting or repeating a sample...

I have a question about PLESIOCHROUNOUS re-sampling of audio. It was mentioned in another thread that simply deleting or repeating a sample now and then is a poor solution because it adds clicks. It was mentioned that linear interpolation is not ideal. Why? Because it adds noise? or distortion? I presume the "ideal" digital solution is to use a higher order interpolation algo...

Hi, I have a conceptual question for the group, which I have been struggling with. It can be summarized as "what is the difference between...

Hi, I have a conceptual question for the group, which I have been struggling with. It can be summarized as "what is the difference between sampling offsets and carrier offsets on a received constellation?". In more detail... Suppose there is a demodulated BPSK signal at the output of an ideal bandpass channel and the receiver is perfect. The received constellation will be at +1, -1. No...

hi on the fdatool i designed a fir hamming filter and generated the m file and got this Fs = 48000; % Sampling Frequency N = 5000;...

hi on the fdatool i designed a fir hamming filter and generated the m file and got this Fs = 48000; % Sampling Frequency N = 5000; % Order Fc1 = 1000; % First Cutoff Frequency Fc2 = 15000; % Second Cutoff Frequency flag = 'noscale'; % Sampling Flag % Create the window vector for the design algorithm. win = hamming(N+1); % Calculate the coefficients using the FIR1 function. ...

hi on the fdatool i designed a fir hamming filter and generated the m file and got this Fs = 48000; % Sampling Frequency N = 5000;...

hi on the fdatool i designed a fir hamming filter and generated the m file and got this Fs = 48000; % Sampling Frequency N = 5000; % Order Fc1 = 1000; % First Cutoff Frequency Fc2 = 15000; % Second Cutoff Frequency flag = 'noscale'; % Sampling Flag % Create the window vector for the design algorithm. win = hamming(N+1); % Calculate the coefficients using the FIR1 function. ...

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...

Hello I need to sample and demodulate an AM-signal that is between 30 kHz to 100 kHz. The signal has a bandwidth of about 10...

Hello I need to sample and demodulate an AM-signal that is between 30 kHz to 100 kHz. The signal has a bandwidth of about 10 kHz. What approach should I use? I?m thinking of using a 16 bit ADC with a maximum sampling frequency of 500 ksps. Maybe using an FPGA to control the ADC. The FPGA can also be used to do the signal processing. How high sampling frequency should...

Hi all, I'm looking for WMA audio streams with differrents combination of bitrate/sampling rate and I canno find them. I need these...

Hi all, I'm looking for WMA audio streams with differrents combination of bitrate/sampling rate and I canno find them. I need these combinations because I want to check a particular player supports the L3 Profile. Also I would like to understand which are the supported streams (in term of bitrate/sampling rate) supported by WMA Std. Can anybody help ? Thanks in advance, Alberto

Please I am a complete newbie in Signal analysis and modelling and I am quite confused about the use of Nyquist theorem in sampling .Does this...

Please I am a complete newbie in Signal analysis and modelling and I am quite confused about the use of Nyquist theorem in sampling .Does this Nyquist criterion affect the rate at which data is transferred that is the data rate ? I have read the wikiopedia saying that I must sample at twice the bandwidth to be able to recontruct a signal perfectly But I don't understand the concept . If ...

Hello On trying to demodulate an OFDM signal based on the DVB-T standard, I immediately encountered difficulties in doing so. The problem lies...

Hello On trying to demodulate an OFDM signal based on the DVB-T standard, I immediately encountered difficulties in doing so. The problem lies in: 1. Frequency offset estimation. 2. Symbol timing estimation (symbol timing ambiguity occurs during the sampling process at the receiver A/D converter. 3. Channel coefficient estimation. Problem 1 is addressed in a straightforward manner usi...

I have a sampled signal that was HP-filtered before sampling. Is there a way to revert the signal back to its pre-HP-filtered state? I know...

I have a sampled signal that was HP-filtered before sampling. Is there a way to revert the signal back to its pre-HP-filtered state? I know it is impossible to restore the DC-component of the signal. But we can assume it is 0V. I MATLAB script to show how the signal x looks HP-filtered: % % Butterworth Highpass filter designed using FDESIGN.HIGHPASS. % All frequency values ar...

Hi All, I need to re-sample a signal sampled at a fixed rate. The fundamental frequency of the signal can be from 45-65Hz. The re-sampling...

Hi All, I need to re-sample a signal sampled at a fixed rate. The fundamental frequency of the signal can be from 45-65Hz. The re-sampling must give 2^N amount of samples per cycle of the fundamental. The employed method must be adaptive - if the fundamental frequency changes, it must still give 2^N samples/Cycle for the current frequency. Anybody have any ideas how to attack this...

Hi community, I'm developing audio algorithm for speech enhancements. Unfortunately the BF533 EZ-Lite is not supporting this sampling rate. So...

Hi community, I'm developing audio algorithm for speech enhancements. Unfortunately the BF533 EZ-Lite is not supporting this sampling rate. So Analog told me to use the "Audio Extender BFAUD-EZEXT". Actually there is only a BF537 driver for this extender, but this is not usable for the BF533. Has somebody a driver to setup a AD1938 codec on the extender board? Cheers Michael

This problem comes from my simulation of Single Carrier Frequency Domain Equalization(SC-FDE) system. Suppose the symbol rate is Ts, for reason...

This problem comes from my simulation of Single Carrier Frequency Domain Equalization(SC-FDE) system. Suppose the symbol rate is Ts, for reason of pulse shaping filtering I perform fractional space sampling with sample rate Ts/2. A FFT block length is 512 and the pilot(used for channel estimation) length is 64. Channel estimation is done as follows: (1) use length 64*2(sampling rate Ts/2) pi...

Hi I have a question regarding the flow of my code. I am oversampling my input signal using the ADC at a rate 3.125 MHz. I have 2 inputs & am...

Hi I have a question regarding the flow of my code. I am oversampling my input signal using the ADC at a rate 3.125 MHz. I have 2 inputs & am using simultaneous sampling. I am using the adcseqovdtest code of TI as a framework. So I have 16 samples from the ADC Result registers. My question is with sampling rate of 3.125 and clock frequency of 150 MHz, I have (150/3.125) 48 instructions per samp...

Steve Minshull wrote: > Tim Wescott wrote: > > > Steve Minshull wrote: > > -- snip -- > > > Hi Tim....Thanks for thinking about...

Steve Minshull wrote: > Tim Wescott wrote: > > > Steve Minshull wrote: > > -- snip -- > > > Hi Tim....Thanks for thinking about this one. I'll try to explain a > little more. > > THe model is presently in continous time but Space Vector PWM doesn't > really exist in continous domain. It works by sampling a DQ voltage > demand and working out a switching vector and dwelling time

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...

I am trying to design a set of bandpass filters for an audio spectrum analyzer. Since human perception of pitch is spaced...

I am trying to design a set of bandpass filters for an audio spectrum analyzer. Since human perception of pitch is spaced logarithmically according to frequency, my low pitches have quite low and narrow bandpass frequencies. I am working in matlab using designing elliptical filters. I am having issues where my lowest filters, passband 8hz to 62hz and 64hz to 247hz are not working. My sampling ...

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...