Signal reconstruction
Analog signal reconstruction from discrete samples.
sampled2continuous(xn, fs, t)
xn |
the sampled input signal, specified as a vector |
fs |
sampling frequency in Hz used in collecting |
t |
time points at which data is to be reconstructed, specified as a
vector relative to |
Given a discrete signal x[n] sampled with a frequency of fs Hz, this
function reconstruct the original analog signal x(t) at time points t.
The function can be used, for instance, to calculate sampling rate effects on
aliasing.
Reconstructed signal x(t), returned as a vector.
Muthiah Annamalai, muthiah.annamalai@uta.edu. Conversion to R by Geert van Boxtel, G.J.M.vanBoxtel@gmail.com.
# 'analog' signal: 3 Hz cosine
t <- seq(0, 1, length.out = 100)
xt <- cos(3 * 2 * pi * t)
plot(t, xt, type = "l", xlab = "", ylab = "", ylim = c(-1, 1.2))
# 'sample' it at 4 Hz to simulate aliasing
fs <- 4
n <- ceiling(length(t) / fs)
xn <- xt[seq(ceiling(n / 2), length(t), n)]
s4 <- sampled2continuous(xn, fs, t)
lines(t, s4, col = "red")
# 'sample' it > 6 Hz to avoid aliasing
fs <- 7
n <- ceiling(length(t) / fs)
xn <- xt[seq(ceiling(n / 2), length(t), n)]
s7 <- sampled2continuous(xn, fs, t)
lines(t, s7, col = "green")
legend("topright", legend = c("original", "aliased", "non-aliased"),
lty = 1, col = c("black", "red", "green"))Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.