Convolución de Sumas - Tabla y propiedades



Tabla de suma de convolución

Referencia: Lathi Tabla 3.1 p285

\gamma_1 \neq \gamma_2
Nox1[n]x2[n]x1[n]⊗x2[n] = x2[n]⊗x1[n]
1δ[n-k]x[n]x[n-k]
2 \gamma^{n} \mu[n]μ[n]\frac{1-\gamma^{n+1}}{1-\gamma} \mu[n]
3μ[n]μ[n](n+1) μ[n]
4 \gamma_1^{n} \mu[n] \gamma_2^{n} \mu[n] \frac{\gamma_1^{n+1} - \gamma_2^{n+1}}{\gamma_1 - \gamma_2} \mu[n]
5 \gamma_1^{n} \mu[n] \gamma_2^{n} \mu[-(n+1) ] \frac{\gamma_1}{\gamma_2 - \gamma_1} \gamma_1^{n} \mu[n] +
+ \frac{\gamma_2}{\gamma_2 - \gamma_1} \gamma_2^{n} \mu[-(n+1)]
    |\gamma_2| > |\gamma_1|
6 n\gamma_1^{n} \mu[n] \gamma_2^{n} \mu[n] \frac{\gamma_1 \gamma_2}{(\gamma_1 - \gamma_2)^2} \Big[ \gamma_2^{n} - \gamma_1^{n} + \frac{\gamma_1 - \gamma_2}{\gamma_2}n \gamma_1^n \Big] \mu [n]
    \gamma_1\neq \gamma_2
7n μ[n]n μ[n] \frac{1}{6} n (n-1) (n+1) \mu [n]
8 \gamma^{n} \mu[n] \gamma^{n} \mu[n] (n+1) \gamma^{n} \mu[n]
9 \gamma^{n} \mu[n] n \mu[n] \Big[ \frac{\gamma(\gamma^{n}-1)+n(1-\gamma)}{(1-\gamma)^2} \Big] \mu[n]
10 |\gamma_1|^{n} \cos (\beta n + \theta) \mu [k] |\gamma_2|^{n}\mu [n] \frac{1}{R} \Big[ |\gamma_1|^{n+1} \cos [\beta (n+1) +\theta -\phi] -\gamma_2 ^{n+1} \cos (\theta - \phi) \Big] \mu[n]
    R=\Big[|\gamma_1|^2 + \gamma_2^2 -2|\gamma_1|\gamma_2 \cos(\beta) \Big]^{\frac{1}{2}}
\phi = \tan ^{-1} \Big[ \frac{|\gamma_1| \sin(\beta)}{|\gamma_1| \cos (\beta) -\gamma_2} \Big]
11\mu [n]n\mu [n] \frac{n(n+1)}{2}\mu [n]


Propiedades de la suma de convolución

Conmutativa

x_1[n] \circledast x_2[n] = x_2[n] \circledast x_1[n]

Distributiva

x_1[n] \circledast (x_2[n]+x_3[n])= (x_1[n] \circledast x_2[n]) + (x_1[n] \circledast x_3[n])

Asociativa

x_1[n] \circledast (x_2[n] \circledast x_3[n]) = (x_1[n] \circledast x_2[n]) \circledast x_3[n]

Desplazamiento

Si

x_1[n] \circledast x_2[n] = c[n]

entonces

x_1[n-m] \circledast x_2[n-p] = c[n-m-p]

Convolución de un impulso

x[n] \circledast \delta[n] = x[n]

Ancho o intervalo

Si x1[n] y x2[n] tienen anchos finitos W1 y W2, el ancho de la convolución entre ellos es W1+W2.




Unidades SS