-1
votes
0answers
5 views

Audio frequency modulation

Wanting to build an audio circuit capable of taking sub-sonic and ultra-sonic audio input and stepping the frequency to human hearing range. Also looking for a mic that would pick up sub- and ultra- ...
0
votes
0answers
8 views

How do i detect if an image has a gradient or not?

I have coloured images, some may be just clipart, some may be artwork, both could be with or without gradients. Before i run a colour counting algorithm on them, i want to detect if the image has ...
0
votes
0answers
7 views

Isolated word classification using LDA

I would like to do a project on speech processing. How can I classify isolated word using linear discriminant analysis for my speaker recognition project.
0
votes
0answers
10 views

Acoustic record and store devices

I am working on a project involving analysis of bird sounds and I want to record these sounds in slightly remote locations. It is enough if the device can only record and store them (maybe in an SD ...
-1
votes
0answers
12 views

Deconvolution of multiple signals

I have 2 matrices in Matlab, both are 53513 x 25 array; One is a raw signal of the 25 samples. Other begin the recorded signal. I was hoping to perform deconvolution between these 2 signals across ...
0
votes
1answer
21 views

FIR Filter length Upper Bound

Say I want to design a low pass filter with stop and pass band ripple constrained to $\epsilon$ and transition region $\delta$, what is the smallest FIR Filter length that suffices? Can you please ...
0
votes
0answers
24 views

Time period to Instantaneous frequency

I have simple smooth time signal with different time period. I would like to transfer period over the time to frequency, and to track frequency changing over the time, I would call it Instantaneous ...
0
votes
0answers
9 views

Barrier load cell digitial filtering with known pre-collision noise

I have a signal processing (filtering) problem that I would love to bounce off the community and receive some feedback. First, the context: Longitudinal barrier load cell force-time data for high ...
0
votes
1answer
25 views

Sample rate changing audio pitch

I am using rtl-sdr at an adjustable sample rate to get stuff from a WBFM radio station. I then filter and demodulate it. When I sample at 2.4Msps, the sound is 'choppy'. I tied the sample rate to a ...
0
votes
0answers
11 views

Algorithm to compare two audio signals: source and recorded file

I have two audio signals: source .wav file, and recorded audio file (.wav). Lets assume both signals have same duration. What algorithm should I use to detect recording quality? Notice that source ...
0
votes
1answer
21 views

Beat Detection with Arduino

I'm trying to make a robot dance on several songs using Arduino. I need to understand how to get the rhythm from the songs, something like detecting the beats, calculating the bpm.. I'm not expert but ...
0
votes
0answers
31 views

How to determine cut-off frequency using power spectral density?

I am new to DSP and my question is a very simple one. It is about determining the right cut-off frequency. I calculate the power spectral density using FFT by Welch's algorithm. However I am confused ...
0
votes
1answer
25 views

Do Causal Discrete-time systems have proper transfer functions?

In the case of continuous-time systems, if the system is causal, its Laplace transfer function is strictly proper (the degree of the numerator is less than the degree of the denominator). Is this ...
0
votes
2answers
42 views

How does 3D Time-of-Flight (TOF) camera work?

This is my first post in this forum! So Point me if anything is not clear! I want to know how TOF camera works? So I've done Google & read some nice explanation about How Phase difference between ...
0
votes
1answer
27 views

Filter to speed up convergence of geometric series

I want to speed up convergence of geometric series $\ \ lim + c^n \ \ $ where $|c| < 1$ and $lim$ is not known. A basic low-pass filter, here Butterworth, is good for $-1 < c < 0$ but not $0 ...
0
votes
0answers
24 views

Why Normalized Cross Correlation Score of different templates is high?

I am using OpenCv's built in template matching function to search for an object in image. I am using Normalized Cross Correlation Method.The function is returning a value which I think indication of ...
0
votes
0answers
27 views

Detecting the durations of randomly occuring sinusoidal pulses

I’m very new to signal processing and eager to learn, but please be gentle… System: I have a single input channel receiving a 44.1kHz 16bit PCM signal. For the majority of the time the channel will ...
3
votes
1answer
49 views

Is it possible to design noncausal filters in Matlab?

I'm trying to design a lowpass IIR filter with 5Hz cutoff frequency (sample frequency is 200Hz). i know how to create it with fdatool, or with functions such as 'butter' or 'ellip'. However, i think ...
2
votes
2answers
29 views

When calculating the Nyquist frequency should carrier frequency be included

This isn't my field, so please forgive any misnomers on my part. I'm looking into buying a amateur radio receiver, and I'm thinking about what sampling rate I need. I'm most interested in satellite ...
0
votes
0answers
9 views

calculating average PSD of N radio frames

i've written a matlab code for the basic ofdm with bpsk modulation. there is no channel coding or compression used at this point. i just want to see the PSD of the transmitted packet. i am getting a ...
1
vote
0answers
23 views

BandPass and StopBand FIR filters (Hamming) is not working

I have two groups of 3 frequencies of tone (music), First Group Tones: 39 (77.7817 Hz), 40 (82.4069 Hz) and 41 (87.3070 Hz). Second Group ...
0
votes
0answers
9 views

Pesq numbers and clean speech comparison to processed speech

I am trying to evaluate my processed speech for my DSP project. My project is an implementation of an MMSE algorithm proposed by Y.Ephraim and D. Malah, "Speech Enhancement Using a Minimum Mean Square ...
0
votes
0answers
23 views

Are convolution and deconvolution kernel the same?

I need to clarify this and rather confused by this. Lets say: x = h * g x - measured data h - raw data g - instrument response function (convolution kernel) . So lets say I have x and h. So ...
0
votes
1answer
48 views

Can I take piecewise FFT of a larger input sample?

I have a N point sequence x. Let X be the fft(x). (Assume x is arbitrary) where, x=[x1 x2 x3 x4 x5 x6 x7 x8] fft(x)=[X1 X2 X3 X4 X5 X6 X7 X8] How do I get the ...
0
votes
1answer
32 views

Why oversample data before using raised cosine filter?

In the process of creating a baseband signal, the complex symbols are filtered using a raised cosine filter to perform pulse shaping (I'm following some literature as a guide). The pulse shaping is ...
2
votes
0answers
15 views

Analytical expression for convolution of two 2D DFTs

I am trying to do an image analysis problem on some images, and I want to calculate some things in the frequency domain which are giving me problems. Say I have an (discrete) image $I(x,y)$ of size ...
0
votes
0answers
9 views

Finding a Priori SNR using decision directed approach from Ephraim and Malah's Paper

I'm using this paper by Y. Ephraim and D. Malah and the decision directed approach mentioned in the paper. But there is this formula eq no 53 which uses recursion to find priori SNR but i am having ...
-2
votes
0answers
21 views

FIR vs. IIR for filter realization [on hold]

What are the pros and cons of using FIR versus IIR structures for the realization of a digital filter ?
-1
votes
0answers
8 views

SRAD code in matlab it doesn't work [on hold]

i just applied the SRAD code in matlab and i get error in line 430 ...
1
vote
2answers
23 views

How to find the output signal of a filter using state space matrices?

I have a filter. It has two poles and two zeros. I found the state space equations and the matrices A, B, C, and D Now. I have 9 samples that I need to process with my filter. How do I use A,B,C,D ...
0
votes
0answers
13 views

Calculating Savitsky-Golay filter coefficients - normalization

using the matrix equations found on Wikipedia i wrote some Python code to compute the Savitsky-Golay coefficients for m data-points, using a polynomial of degree k, here it is: ...
1
vote
1answer
42 views

Sub pixel shift causes weird results

I am trying to shift an image on a subpixel level, with the method described here: ...
0
votes
2answers
39 views

FIR filter design with frequency sampling method - setting proper phase response for IDFT

I'd like to implement freuqency sampling method for linear phase FIR filter design using IDFT transform. My procedure goes like this : determine desired magnitude response value in frequency points ...
0
votes
1answer
44 views

Phase Estimation in speech enhancement

I am reading a recent paper titled "Phase Estimation of Speech Enhancement - unimportant, important, or impossible?" by Grekmann et al. published in the 2012 the IEEE convention. The paper proposes an ...
0
votes
0answers
21 views

Choosing the frequency for a comb filter

I have an audio sample. From doing FFT on it it looks as if I need to use a comb filter to remove resonant frequencies. This is what I generate: I honestly have no clue where to start ...
0
votes
1answer
38 views

Frequency of a noisy signal with fixed width pulses

My electricity meter has a front panel LED which pulses in proportional to the current energy rate. The frequency changes but the pulse width is set at 250ms. Due to environmental conditions there's ...
0
votes
0answers
23 views

Feature extraction and Variance

I see there is a relationship between the Variance of a signal (i.e EEG signal) and features extraction of that signal. for example PCA tend to take almost of the variance of the original signal , but ...
0
votes
1answer
89 views

Why does FFT generate a jaggedy signal

I have an application that fills a buffer from my computer's microphone and does an FFT. My objective is to figure out what frequencies are in the sample. I've tested the application by whistling as ...
0
votes
0answers
18 views

Bit Error Rate of K-means [closed]

Can you help me in finding the bit error rate after applying the K-means clustering algorithm on observations. Thank you Kawther
0
votes
1answer
41 views

Converting raw I/Q to dB

I am getting I/Q data from a software-defined radio. I want to do some stuff on signals in the data, but only if it exceeds a certain range. What is the general procedure to get dB (dBm, or ...
0
votes
0answers
22 views

Adaptive Line noise removal using IIR notch filters

I'm trying to filter out line noise(60Hz and 120Hz) from a EEG signals received over a bluetooth link. I'm proposing to use a IIR notch filter to filter out the line-noise which varies w.r.t to ...
2
votes
2answers
57 views

Effects of DC offset on a signal

What are some of the reasons why DC offset is considered undesirable for a timeseries signal other than wastage of power during transmission ? Specifically, How does it cause spectral leakage and out ...
2
votes
2answers
38 views

convolution matrix for image scaling

Is there any way how to compute convolution matrix for Nearest Neighbor (bicubic, bilinear) image scaling (upscale/downscale)?
-2
votes
0answers
22 views

work on paper useing matlab dsp

I'm going on a research paper on the cardiac signal processing methods, the implementation and practice. Downloads In: http://s5.picofile.com/file/8153336292/DSP_Project_1393_1_.pdf.html In this ...
0
votes
1answer
34 views

The Nyquist-Theorm behind the fft

I saw a code in Python in the scipy.org (http://docs.scipy.org/doc/scipy-dev/reference/tutorial/fftpack.html) and found this: First question: Is it right that T = 1/800 <==> fs = 800 Hz fulfill ...
0
votes
0answers
10 views

SURF SIFT detection

Do you have any idea if the surf extracted or detected interest points belongs to the same objects? I explain: SURF descriptor account the orientation of ip based on edges intensities around it. In ...
1
vote
1answer
42 views

Need help to understanding concept of particle filter

I get confuse with the basic theory of particle filter for tracking single object.. What I want to ask is: In some paper, they explained about velocity in state vector.. Are we randomly put number ...
0
votes
1answer
16 views

Quadrature subsampling result not as expected

Let's suppose I have an ADC running at 81.824MHz. I am quadrature subsampling a signal that is at 143.5MHz using a sampling rate of 81.824MHz/4 = 20.456MHz = Fs. I expect the signal to appear at ...
0
votes
0answers
17 views

Simple stats and sampling question

Please correct me if I am wrong here... If I am sampling a signal whose value is constant I measure N times for N samples. I then get a mean and standard deviation (SD). I obtain a relative standard ...
0
votes
1answer
23 views

Shape recognition, hough transform

I'm trying to match a picture saying "this is ducks, this is towers" by giving votes from the hough transform of a picture. I've found this article ...

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