Tabla de suma de convolución
Referencia: Lathi Tabla 3.1 p285
\gamma_1 \neq \gamma_2| No | x1[n] | x2[n] | x1[n]⊗x2[n] = x2[n]⊗x1[n] |
|---|---|---|---|
| 1 | δ[n-k] | x[n] | x[n-k] |
| 2 | \gamma^{n} \mu[n] | μ[n] | \frac{1-\gamma^{n+1}}{1-\gamma} \mu[n] |
| 3 | μ[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 | |||
| 7 | n 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.