Questions on the mathematical aspects of signal processing. Please consider first if your question might be more suitable for http://dsp.stackexchange.com/
Questions tagged [signal-processing]
2068 questions
0
votes
1 answer
Cross-fading between 2 values on number lines.
Background:
I'm working on writing a software application where I need to cross fade between 2 digital audio signals. In the software I have 4 variables that play a role:
float sampleA; //The value of signal A in this very instant (values from -1…
BRHSM
- 117
0
votes
0 answers
Pre-Emphasis of a signal
I'm trying to describe the process of Pre-Emphasis (of a signal) in my equations, but I don't know whether or not this makes sense.
$Y[n] = X[n] - 0.95 \cdot X[n-1]$
Where Y = pre-emphasis after, X = inputted signal
Given:-
$X =…
Phorce
- 219
0
votes
1 answer
Why add one to denominator when calculating discrete signal average power?
In order to calculate the average power of a continuous signal we use the following formula:
Which makes logical sense to me. However, when we're calculating it for a discrete signal, then we use the following formula:
My question, and confusion,…
ScottishTapWater
- 117
0
votes
1 answer
Measuring a faint ripple
I am working on an electronics problem where we measure some faint ripple over a huge constant. You can think of it as $100 \,\rm{V}$ DC plus a ripple of $\pm$ a couple $\rm{mV}$ over that $100\,\rm{V}$. Our signal-to-noise (SNR) calculation is…
user8922
0
votes
1 answer
Time delay between two sines
Let's assume two sine waves
$$\begin{align}
u(t) &= \hat u \sin(\omega t + \phi_u)\\
y(t) &= \hat y \sin(\omega t + \phi_y)
\end{align}$$
whose phase shift can be calculated as
$$ \Delta\phi = \phi_y - \phi_u.$$
How can I now derive the time delay…
Pascal
- 137
0
votes
0 answers
Relation between the unit sample sequence δ[n] and the unit step sequence u[n]
The discrete time unit step is given by $$ u[n] =
\begin{cases}
1, & n \geq 0, \\
0, & n < 0.
\end{cases}
\tag{1}
$$
Unit Sample sequence or Impulse sequence is defined as $$ δ[n] =
\begin{cases}
1, & n = 0, \\
0, & n ≠ 0.
\end{cases}
\tag{2}
$$
and…
0
votes
2 answers
When writing out the wave equation isn't the phase shift just adding to the frequency?
I hope someone here could clarify for me.
With the waveform function f()=(A)sin(wt + theta)
where
A=magnitude of the wave,
sin= type of wave form,
wt=frequency rads/sec,
theta = phase shift
...isn't wt + theta just giving us a different…
Chef Flambe
- 165
0
votes
1 answer
Derivative of arctangent
I need a closed-form expression for the time derivative of the arctangent of a ratio of two time-dependent variables. I need advice because a credible reference I found doesn't produce the expected result.
After decomposing a real-valued signal into…
Brian K1LI
- 101
0
votes
1 answer
Maximum order of persistence of excitation input signal u
I have a quick question,
This is an exam question for the course System Identification:
Consider the following periodic input signal $u(t)$:
$u(t) = 0, \quad t = 0,3$
$u(t) = 1, \quad t = 1,4$
$u(t) = -1, \quad t = 2,5$
The question is "Determine…
user463102
- 449
0
votes
1 answer
Determine impulse response with given input and output
There is a problem with LTI System.
I need to find an impulse response from given input and output from stable LTI System.
This is my input signal:
Input
Let I write it like a vector.
$x_n = \{1, 2, 1\}$
This is my output signal:
Output
$y_n = \{0,…
0
votes
1 answer
Find the time-averaged power of a signal
So I'm asked to find the time-averaged power of the following continuous signal: $$z(t) = \sqrt{E} \sum_{k=-\infty}^{+\infty} A_k g(t-kT)$$ where $A_k =1$ if $|k|$ is a prime number and $A_k=-1$ otherwise, and where $g(t)=1$ for $0 \leq t \leq T$…
Skyris
- 376
0
votes
0 answers
How to apply AM to a signal
i am trying to understand how amplitude modulation works; i have already understood that it is given by the following:
$$AM (f(t)) = cos2πτt * f(t),$$
where τ is the frequency of the sinusoid.
So for example, if i were given a function like:
$$f(t)…
zorro
- 13
0
votes
0 answers
How to calculate system response with input given?
i am trying to understand how system responses and impulse responses work.
Given that i have a system described by the following expression:
$y(n) = 3x(n+2) + 2x(n) - 4x(n-2)$
I want to calculate the system response when the signal x(n) is:
$x(n)…
zorro
- 13
0
votes
1 answer
Calculate impulse response for given system
i am given an exercise in which i need to find the impulse response for this given system:
$$y(n) = 2x(n-2) + x(n) -2x(n+2)$$
This is the only information i have.
I don't even understand which formula should be applied to get the result.
May any…
zorro
- 13
0
votes
1 answer
determine autocorrelation of given block signal
How are these autocorrelations determined?
user463102
- 449