9 votes
Accepted

Why doesnt DFT Padding cause sinc like features

The OP is showing very good insight in all the comments stated. A product in the time domain with a rectangular pulse is convolution in the frequency domain with a Sinc. In fact zero padding in time ...
Dan Boschen's user avatar
  • 51.4k
4 votes

Why doesnt DFT Padding cause sinc like features

@George kirby. I suggest you discard that notion of "multiplying a step function on top of the original signal to form a longer time sequence". I believe such a multiplication is not ...
Richard Lyons's user avatar
2 votes

Why doesnt DFT Padding cause sinc like features

lots of good stuff in the above answer. But you can absolutely see the sinc function in the frequency domain - just pick a sin wave that's got a period that evenly divides the new signal length. For ...
njudell's user avatar
  • 21
1 vote
Accepted

Trying to replicate results from tfestimate function in Matlab

I can confirm the following algorithm successfully replicates the tfestimate function for my signals $x(n)$ and $y(n)$, Algorithm Divide $x(k)$ and $y(k)$, where $k=0,1,\ldots,N-1$, into data ...
wolfiesax's user avatar
1 vote
Accepted

What function can be used to describe periodicity of the signal

You are sampling, then resampling, then (essentially) filtering. Everything that you see can be explained because of the combination of these effects. You're starting with a signal at 100Hz: $x(t) = \...
TimWescott's user avatar
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1 vote

Calculating stopband cut-off frequency and stopband attenuation for FIR lowpass window filter

Some helpful advice: The order of 5 for an FIR filter is very small. I assume from the OP's comment that the exercise will be to compare FIR and IIR filters for very small order. Plotting the spectrum ...
Dan Boschen's user avatar
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1 vote

Spreading sequence for dsss or cdma

Why is this type of sequence never used? Complex spreading sequences are used all over the place: OFDMA is a special case of CDMA, for example.
Marcus Müller's user avatar
1 vote
Accepted

How to select the location of submatrices to have specific property in the output of multiplication

Your condition is $W_{2,2} W_{2,2}^T = I$ $T = W_{2,2}^{-1} W_{2,1}$ If $T$ has non-zero elements only in the first collumn it means that $T = \begin{bmatrix} \textbf C & \textbf 0_{P \times (P-r)}...
Bob's user avatar
  • 2,373

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