R/turbo_code.R
In DaniWi/Channelcoding: channelcoding
# turbo_code_rcpp.R
#
# interface for turbo codes
# provided functions:
# - TurboEncode
# - TurboDecode
# - TurboGetpermutation
# - TurboGetPunctuationMatrix
# - TurboSimutlation
# - TurboOpenPDF
#' Encode a message with the turbo-code.
#'
#' This functions takes a message and encode it with the turbo-code procedure. The message
#' will be encoded in 2 identical systematic encoder, but before the message will be encoded in the encoder 2
#' the message will be permutated with an interleaver. To increase the minimal distance between 2 code words
#' the interleaver is needed. The systematic encoder must have 2 exists and it must be
#' an systematic encoder which means that the input is redirected directly to the output.
#' Because of the systematic encoders the original message must be transmitted only once, so
#' this procedure reduces the code rate of the whole encoder. After the 2 encoders the
#' resulting encoded messages are interleaved into one stream and transmitted to the exit.
#' Only one exit of the systematic encoder will be used, so the index of the output can be
#' determined. The punctuation matrix removes all bits where the matrix is zero, so the
#' code rate is increased.
#'
#' @author Witsch Daniel
#'
#' @param message Message which will be encoded.
#' @param permutation.vector Permutation vector which will be created with \code{\link{TurboGetPermutation}}.
#' @param coder.info Coder which will be created with \code{\link{ConvGenerateEncoder}} or \code{\link{ConvGenerateRscEncoder}}.
#' @param parity.index Index to decide which exit of the coder will be used for the encoding (>1).
#' Default value is always the last exit of the coder.
#' @param punctuation.matrix Punctuation matrix to puncture the output, will be created with \code{\link{TurboGetPunctuationMatrix}}.
#' @param visualize Flag to decide whether to create a visualization pdf or not.
#'
#' @return Encoded message, will be a list if the output was punctured (list with original and punctured).
#'
#' @examples
#' input <- c(1,0,1,1,0)
#'
#' #default coder and permutation vector
#' message.encoded <- TurboEncode(input)
#' print(message.encoded)
#'
#' #custom coder and permutation vector
#' coder <- ConvGenerateRscEncoder(2, 2, c(5, 7))
#' perm <- TurboGetPermutation(length(input), coder, "RANDOM")
#' message.encoded <- TurboEncode(input, perm, coder)
#' print(message.encoded)
#'
#' #encoding with punctuation matrix
#' punct <- TurboGetPunctuationMatrix(c(1,1,0,1,0,1))
#' message.encoded.punct <- TurboEncode(input, perm, coder, punctuation.matrix = punct)
#' print(message.encoded.punct$original)
#' print(message.encoded.punct$punctured)
#'
#' @export
TurboEncode <-
function(message,
permutation.vector = NULL,
coder.info = NULL,
parity.index = coder.info$N,
punctuation.matrix = NULL,
visualize = FALSE) {
if (is.null(coder.info)) {
warning("Standard-Coder was used! RSC, N=2, M=2, Generators: (5,7)")
coder.info <- ConvGenerateRscEncoder(2,2,c(5,7))
}
if (is.null(permutation.vector)) {
warning("Standard-Permutationvector was used! (PRIMITIVE)")
permutation.vector <- TurboGetPermutation(length(message), coder.info, "PRIMITIVE", list(root=0))
}
#Checks all parameters
stopifnot(length(message) > 0)
CheckCoder(coder.info)
if (any((message != 1)[message != 0])) {
stop("Message should only contain 0 and 1!")
}
if (coder.info$N < 2) {
stop("Coder must have minimum 2 exists!")
}
if (coder.info$rsc != TRUE && coder.info$generators[1] != (2 ^ coder.info$M)) {
stop("Coder must be an systematic coder!
(exit 1 must have polynom 2^M or it must be a rescursiv coder)")
}
if (length(permutation.vector) != (length(message) + coder.info$M)) {
stop("Permutation vector has the wrong length!")
}
if (any(is.na(match(0:(length(permutation.vector) - 1), permutation.vector)))) {
stop("Permutation vector has the wrong entries!")
}
if (!is.null(punctuation.matrix) && nrow(punctuation.matrix) != 3) {
stop("Punctuation matrix has the wrong amount of rows,
with turbo codes it has to be 3!")
}
#when parity.index is too high or to low
if (parity.index > coder.info$N || parity.index < 0) {
parity.index = coder.info$N
}
#first coder with termination
parity.1 <- ConvEncode(message, coder.info, TRUE)
#extract original message with termination bits from parity
temp.index <- c(rep(FALSE, 0), TRUE, rep(FALSE, coder.info$N - 1))
code.orig <- parity.1[temp.index]
#permutate original message with termination (mapping important!!)
code.orig.01 <- as.numeric(code.orig < 0)
code.perm <- as.numeric(code.orig[permutation.vector + 1] < 0)
#second coder without termination
parity.2 <- ConvEncode(code.perm, coder.info, FALSE)
#extract parity bits from the output messages
temp.index <- c(rep(FALSE, parity.index - 1), TRUE, rep(FALSE, coder.info$N - parity.index))
parity.1 <- parity.1[temp.index]
parity.2 <- parity.2[temp.index]
code.result <- Interleave(code.orig, parity.1, parity.2)
if (!is.null(punctuation.matrix)) {
#puncture the output
code.punct <- PunctureCode(code.result, punctuation.matrix)
}
if (visualize) {
if (length(message) > 10) {
warning("Maybe not the whole informations could be visualized!")
}
if (!is.null(punctuation.matrix)) {
rmarkdown::render(
system.file("rmd", "TurboEncodePunctured.Rmd", package = "channelcoding"),
output_dir = system.file("pdf", package = "channelcoding"),
params = list(
orig = code.orig.01,
interl = code.perm,
parity1 = parity.1,
parity2 = parity.2,
multipl = code.result,
result = code.punct,
permutation = permutation.vector,
punctuation = punctuation.matrix,
encoder = coder.info),
encoding = "UTF-8")
rstudioapi::viewer(system.file("pdf", "TurboEncodePunctured.pdf", package = "channelcoding"))
} else {
rmarkdown::render(
system.file("rmd", "TurboEncode.Rmd", package = "channelcoding"),
output_dir = system.file("pdf", package = "channelcoding"),
params = list(
orig = code.orig.01,
interl = code.perm,
parity1 = parity.1,
parity2 = parity.2,
result = code.result,
permutation = permutation.vector,
encoder = coder.info),
encoding = "UTF-8")
rstudioapi::viewer(system.file("pdf", "TurboEncode.pdf", package = "channelcoding"))
}
}
if (!is.null(punctuation.matrix)) {
return(list(original = code.result, punctured = code.punct))
} else {
return(code.result)
}
}
#' Decode a code which is encoded with the turbo-code.
#'
#' The code will be decoded with the turbo-code procedure. The given coder must be an
#' systematic coder and should have at least 2 exits. To decide which exit is used, the user
#' can decide this with the parameter index. The principle of turbo decoding is that
#' the decoding is a iterative method, so code will be passed through the decoder multiple times.
#' With the parameter iteration you can decide how often the decoders are passed through.
#' After each iteration the result should be better and the result of the last iteration will
#' be used in the next iteration as input values. The exact signal level of the input will be used
#' as input in the first iteration. When punctuation was used during encoding it is important
#' that the same punctuation is given in the decoding because all bits which are deleted can now
#' be inserted again.
#'
#' @author Witsch Daniel
#'
#' @param code Code which will be decoded to the original message.
#' @param permutation.vector Permutation vector which will be created with \code{\link{TurboGetPermutation}}.
#' @param iterations Amount of decoding iterations.
#' @param coder.info Coder which will be created with \code{\link{ConvGenerateEncoder}} or \code{\link{ConvGenerateRscEncoder}}.
#' @param parity.index Index to decide which exit of the coder will be used for the encoding (>1).
#' Default value is always the last exit of the coder.
#' @param punctuation.matrix Punctuation matrix to puncture the output, will be created with \code{\link{TurboGetPunctuationMatrix}}.
#' @param visualize Flag to decide whether to create a visualization pdf or not.
#'
#' @return Decoded message, will be a list (soft and hard values).
#'
#' @examples
#' input <- c(1,0,1,1,0)
#'
#' #default coder and permutation vector
#' message.encoded <- TurboEncode(input)
#' result <- TurboDecode(message.encoded, iterations = 5)
#' print(result)
#'
#' #custom coder and permutation vector
#' coder <- ConvGenerateRscEncoder(2, 2, c(5, 7))
#' perm <- TurboGetPermutation(length(input), coder, "RANDOM")
#' message.encoded <- TurboEncode(input, perm, coder)
#' result <- TurboDecode(message.encoded, perm, 5, coder)
#' print(result)
#'
#' #decoding with punctuation matrix
#' punct <- TurboGetPunctuationMatrix(c(1,1,0,1,0,1))
#' message.encoded.punct <- TurboEncode(input, perm, coder, punctuation.matrix = punct)
#' result <- TurboDecode(message.encoded.punct$punctured, perm, 5, coder, punctuation.matrix = punct)
#' print(result)
#'
#' @export
TurboDecode <-
function(code,
permutation.vector = NULL,
iterations = 1,
coder.info = NULL,
parity.index = coder.info$N,
punctuation.matrix = NULL,
visualize = FALSE) {
if (!is.numeric(code) || !is.vector(code)) {
stop("Code was not a numeric vector! Check the code parameter!")
}
if (is.null(coder.info)) {
warning("Standard-Coder was used! RSC, N=2, M=2, Generators: (5,7)")
coder.info <- ConvGenerateRscEncoder(2,2,c(5,7))
}
#Checks all parameters
stopifnot(length(code) > 0, iterations > 0)
CheckCoder(coder.info)
if (coder.info$N < 2) {
stop("Coder must have minimum 2 exists!")
}
if (coder.info$rsc != TRUE && coder.info$generators[1] != (2 ^ coder.info$M)) {
stop("Coder must be an systematic coder!
(exit 1 must have polynom 2^M or it must be a rescursiv coder)")
}
if (!is.null(permutation.vector) && any(is.na(match(0:(length(permutation.vector) - 1), permutation.vector)))) {
stop("Permutation vector has the wrong entries!")
}
if (!is.null(punctuation.matrix) && nrow(punctuation.matrix) != 3) {
stop("Punctuation matrix has the wrong amount of rows,
with turbo codes it has to be 3!")
}
#when parity.index is too high or to low
if (parity.index > coder.info$N || parity.index < 0) {
parity.index = coder.info$N
}
#Punctuation
if (!is.null(punctuation.matrix)) {
#insert missing bits from punctuation
code.with.punct <- InsertPunctuationBits(code, punctuation.matrix)
} else {
code.with.punct <- code
}
#create the default permutation.vector
if (is.null(permutation.vector)) {
warning("Standard-Permutationvector was used! (PRIMITIVE)")
permutation.vector <- TurboGetPermutation(length(code.with.punct) / 3 - coder.info$M, coder.info, "PRIMITIVE", list(root=0))
}
#Check length of input(with inserted bits) and permutation.vector
if ((length(code.with.punct) %% 3) != 0) {
if (!is.null(punctuation.matrix)) {
stop("Mistake during depunctation!")
}
stop("Code has the wrong length! (Code is maybe punctuated)")
}
if (length(permutation.vector) != (length(code.with.punct) / 3)) {
stop("Permutation vector has the wrong length!")
}
#parse original parts of the code from input code
code.length <- length(code.with.punct) / 3
code.orig <- Deinterleave(code.with.punct, 1)
parity.1 <- Deinterleave(code.with.punct, 2)
parity.2 <- Deinterleave(code.with.punct, 3)
#decode message (c-function)
decoded <-
c_turbo_decode(
code.orig,
parity.1,
parity.2,
permutation.vector,
iterations,
coder.info$N,
coder.info$M,
coder.info$prev.state,
coder.info$output,
parity.index
)
#delete termination bits from result
output.soft <- head(decoded$soft.output, code.length - coder.info$M)
output.hard <- head(decoded$hard.output, code.length - coder.info$M)
message.decoded <- list(output.soft = output.soft, output.hard = output.hard)
if (visualize) {
if (length(output.hard) > 10 || iterations > 10) {
warning("Maybe not the whole informations could be visualized!")
}
if (!is.null(punctuation.matrix)) {
rmarkdown::render(
system.file("rmd", "TurboDecodePunctured.Rmd", package = "channelcoding"),
output_dir = system.file("pdf", package = "channelcoding"),
params = list(
code = code,
punctured = code.with.punct,
orig = code.orig,
parity1 = parity.1,
parity2 = parity.2,
origI = decoded$disp.info$origI,
decode1 = decoded$disp.info$decode1,
decode1I = decoded$disp.info$decode1I,
decode2Back = head(decoded$disp.info$decode2Back, iterations - 1),
decode2IBack = head(decoded$disp.info$decode2IBack, iterations - 1),
decode2 = tail(decoded$disp.info$decode2Back, 1)[[1]],
decode2I = tail(decoded$disp.info$decode2IBack, 1)[[1]],
tempResultSoft = decoded$disp.info$tempResultSoft,
tempResultHard = decoded$disp.info$tempResultHard,
result = message.decoded,
iterations = iterations,
permutation = permutation.vector,
punctuation = punctuation.matrix,
encoder = coder.info),
encoding = "UTF-8")
rstudioapi::viewer(system.file("pdf", "TurboDecodePunctured.pdf", package = "channelcoding"))
} else {
rmarkdown::render(
system.file("rmd", "TurboDecode.Rmd", package = "channelcoding"),
output_dir = system.file("pdf", package = "channelcoding"),
params = list(
code = code,
orig = code.orig,
parity1 = parity.1,
parity2 = parity.2,
origI = decoded$disp.info$origI,
decode1 = decoded$disp.info$decode1,
decode1I = decoded$disp.info$decode1I,
decode2Back = head(decoded$disp.info$decode2Back, iterations - 1),
decode2IBack = head(decoded$disp.info$decode2IBack, iterations - 1),
decode2 = tail(decoded$disp.info$decode2Back, 1)[[1]],
decode2I = tail(decoded$disp.info$decode2IBack, 1)[[1]],
tempResultSoft = decoded$disp.info$tempResultSoft,
tempResultHard = decoded$disp.info$tempResultHard,
result = message.decoded,
iterations = iterations,
permutation = permutation.vector,
encoder = coder.info),
encoding = "UTF-8")
rstudioapi::viewer(system.file("pdf", "TurboDecode.pdf", package = "channelcoding"))
}
}
return(message.decoded)
}
#' Function to generate a permutation vector.
#'
#' This function is a helper function which helps the user to create different permutation
#' vectors. With the argument \code{type} the user can choose one of 6 different interleaver types.
#' Some interleaver need additional informations in the \code{args} argument.
#'
#'
#' \itemize{
#' \item RANDOM: Creates a random permutation vector. No arguments in \code{args}.
#' \item PRIMITIVE: Shift the initial vector (\code{c(1,2,3,...)}) so that the \code{args$root}
#' value is the index of the 1.
#' \item CYCLIC: Creates a initial matrix with the arguments \code{args$cols}, \code{args$rows}
#' and shift each row of the matrix by the index of the row multiplied by the \code{args$distance}.
#' The resulting permutation vector is read out from top to bottom from each column of the matrix.
#' \item BLOCK: This is a type of interleaver in which the bits are read in from left to right in each row from the matrix
#' and read out from top to bottom each column. With the arguments \code{args$cols}, \code{args$rows}
#' the user can change the matrix size.
#' \item HELICAL: This is a type of interleaver in which the bits are read in from left to right in each row from the matrix
#' and read out from left top to bottom right. When the last row of the matrix is arrived
#' then the next bit is read out from the first row but from the next column. With the arguments \code{args$cols}, \code{args$rows}
#' the user can change the matrix size.
#' \item DIAGNOAL: The difference to the HELICAL interleaver is that when the last row is arrived
#' the next bit is in the first row and the first unused column. With the arguments \code{args$cols}, \code{args$rows}
#' the user can change the matrix size.
#' }
#'
#' @param message.length Length of message which will be encoded.
#' @param coder.info Coder which will be used for encoding and decoding.
#' @param type Type of the interleaver, possibilities: RANDOM, PRIMITIVE, CYCLIC, BLOCK
#' HELICAL, DIAGONAL.
#' @param args Arguments for some interleaver. (must be a list)
#' @param visualize Flag to visualize the resulting permutation matrix/vector.
#'
#' @return Created permutation vector.
#'
#' @examples
#' input <- c(1,0,1,1,0,1)
#' coder <- ConvGenerateRscEncoder(2, 2, c(5, 7))
#'
#' #RANDOM
#' permutation <- TurboGetPermutation(length(input), coder, "RANDOM")
#'
#' #PRIMITIV
#' permutation <- TurboGetPermutation(length(input), coder, "PRIMITIVE", list(root=2))
#'
#' #CYCLIC
#' permutation <- TurboGetPermutation(length(input), coder, "CYCLIC", list(cols=2, rows=4, distance=2))
#'
#' #BLOCK
#' permutation <- TurboGetPermutation(length(input), coder, "BLOCK", list(cols=2, rows=4))
#'
#' #HELICAL
#' permutation <- TurboGetPermutation(length(input), coder, "HELICAL", list(cols=2, rows=4))
#'
#' #DIAGONAL
#' permutation <- TurboGetPermutation(length(input), coder, "DIAGONAL", list(cols=2, rows=4))
#'
#' @export
TurboGetPermutation <- function(message.length,
coder.info,
type = "RANDOM",
args = NULL,
visualize = FALSE) {
stopifnot(message.length > 0)
CheckCoder(coder.info)
if (!is.character(type)) {
stop("Type must be an string!")
}
switch(type,
RANDOM = {
interleaver <- sample(c(0:(message.length + coder.info$M - 1)))
if (visualize) {
print(paste("Interleaver-Vector: ", type))
print(interleaver)
}
return(interleaver)
},
PRIMITIVE = {
if (is.null(args$root)) {
stop("Argument args$root was not set!")
}
N <- message.length + coder.info$M - 1
init <- c(0:N)
interleaver <- (init - args$root) %% (N + 1)
if (visualize) {
print(paste("Interleaver-Vector: ", type))
print(interleaver)
}
return(interleaver)
},
CYCLIC = {
if (is.null(args$rows) |
is.null(args$cols) | is.null(args$distance)) {
stop("Argumente (args) was not set correctly!")
}
rows <- args$rows
cols <- args$cols
if (rows * cols != (message.length + coder.info$M)) {
stop("Length of input does not match the amount of rows and columns!")
}
N <- rows * cols
init <- matrix(c(0:(N - 1)), nrow = rows, byrow = FALSE)
i <- 0
interleaver <-
t(apply(init, 1,
function(x) {
temp <- Shift(x, args$distance * (i))
i <<- i + 1
return(temp)
}
))
if (visualize) {
print("Initial-Matrix")
print(init)
print(paste("Interleaver-Matrix: ", type))
print(interleaver)
}
return(as.vector(interleaver))
},
BLOCK = {
if (is.null(args$rows) | is.null(args$cols)) {
stop("Argumente (args) was not set correctly!")
}
rows <- args$rows
cols <- args$cols
if (rows * cols != (message.length + coder.info$M)) {
stop("Length of input does not match the amount of rows and columns!")
}
N <- rows * cols
init <- matrix(c(0:(N - 1)), nrow = rows, byrow = TRUE)
if (visualize) {
print("Initial-Matrix")
print(init)
print(paste("Interleaver-Vector: ", type))
print(as.vector((init)))
}
return(as.vector((init)))
},
HELICAL = {
if (is.null(args$rows) | is.null(args$cols)) {
stop("Argumente (args) was not set correctly!")
}
rows <- args$rows
cols <- args$cols
if (rows * cols != (message.length + coder.info$M)) {
stop("Length of input does not match the amount of rows and columns!")
}
N <- rows * cols
init <- vector(mode = "numeric", length = N)
i <- 0
interleaver <-
sapply(init, function(x) {
x <- (((i %% cols) + (i * cols)) %% N)
i <<- i + 1
return(x)
})
if (visualize) {
print("Initial-Matrix")
print(matrix(c(0:(N - 1)), nrow = rows, byrow = TRUE))
print(paste("Interleaver-Vector: ", type))
print(interleaver)
}
return(interleaver)
},
DIAGONAL = {
if (is.null(args$rows) | is.null(args$cols)) {
stop("Argumente (args) was not set correctly!")
}
rows <- args$rows
cols <- args$cols
if (rows * cols != (message.length + coder.info$M)) {
stop("Length of input does not match the amount of rows and columns!")
}
N <- rows * cols
init <- vector(mode = "numeric", length = N)
i <- 0
interleaver <-
sapply(init, function(x) {
x <- (i * cols) %% N + (i %/% rows + i %% rows) %% cols
i <<- i + 1
return(x)
})
if (visualize) {
print("Initial-Matrix")
print(matrix(c(0:(N - 1)), nrow = rows, byrow = TRUE))
print(paste("Interleaver-Vector: ", type))
print(interleaver)
}
return(interleaver)
}
)
stop("Type of interleaver (type) was not set correctly!")
}
#' Create a punctuation matrix from a vector.
#'
#' This is a helper function to create a correct punctuation matrix. The punctuation.vector
#' should only contain 0 and 1 and has to be a length which is a multiple of 3. The resulting
#' punctuation matrix should not contain a 0 column because this could cause an error during
#' decoding.
#'
#' @param punctuation.vector Vector which will be mapped to the matrix.
#' @param visualize Flag to visualize the resulting punctuation matrix.
#'
#' @return Punctuation matrix for encoder and decoder.
#'
#' @examples
#' TurboGetPunctuationMatrix(c(1, 1, 0, 1, 0, 1), TRUE)
#'
#' @export
TurboGetPunctuationMatrix <- function(punctuation.vector, visualize = FALSE) {
if (any((punctuation.vector != 1)[punctuation.vector != 0])) {
stop("Invalid punctuation vector! Only values 0/1 are allowed!")
}
if (length(punctuation.vector) %% 3 != 0) {
stop("Wrong length of punctuation vector! Must be a multiple of 3!")
}
mat <- matrix(punctuation.vector, nrow = 3)
if (visualize) {
print("Punctuation-Matrix:")
print(mat)
}
if (any(colSums(mat) == 0)) {
stop("Punctuation matrix should not have a 0 column!")
}
return(mat)
}
#' Function to make a automatic simulation of an coder with different signal/noise ratio.
#'
#' This easy functions makes it possible to compare different coders. The function encode
#' a random message, apply noise to the code and then decode the code. This will be computed
#' many times and after all iterations the bit error rate will be calculated. This procedure
#' is applied to different signal/noise ratios. The result will be printed in a graph, when
#' visualization flag is set to TRUE.
#'
#' @param coder Coder which will be created with \code{\link{ConvGenerateEncoder}} or \code{\link{ConvGenerateRscEncoder}}.
#' @param permutation.type Type of permutation vector.
#' @param permutation.args Arguments to the \code{\link{TurboGetPermutation}} function.
#' @param decode.iterations Amount of decoding iterations inside the turbo decoder.
#' @param msg.length Length of the randomly created message.
#' @param min.db Start value of the signal/noise ratio.
#' @param max.db End value of the signal/noise ration.
#' @param db.interval Interval which will be added to the actual signal/noise ratio after all
#' iterations are applied.
#' @param iterations.per.db Amount of iterations each signal/noise ration step.
#' @param punctuation.matrix Punctuation matrix to puncture the output, will be created with \code{\link{TurboGetPunctuationMatrix}}.
#' @param visualize Flag to decide whether to create a visualization pdf or not.
#'
#' @return DataFrame which contains the bit error rate for each signal/noise ratio step.
#'
#' @examples
#' #all default parameters
#' TurboSimulation()
#'
#' #without punctuation
#' coder <- ConvGenerateRscEncoder(2, 2, c(5, 7))
#' TurboSimulation(coder, "RANDOM", NULL, 5, 10, 0.01, 1, 0.05, 50, NULL, FALSE)
#'
#' @export
TurboSimulation <- function(coder = NULL,
permutation.type = "PRIMITIVE",
permutation.args = list(root=0),
decode.iterations = 5,
msg.length = 100,
min.db = 0.1,
max.db = 2.0,
db.interval = 0.1,
iterations.per.db = 100,
punctuation.matrix = NULL,
visualize = FALSE)
{
stopifnot(decode.iterations > 0, msg.length > 0, iterations.per.db > 0,
min.db > 0, max.db > 0, max.db >= min.db, db.interval > 0)
if (is.null(coder)) {
warning("Standard-Coder was used! RSC, N=2, M=2, Generators: (5,7)")
coder <- ConvGenerateRscEncoder(2,2,c(5,7))
}
v.db <- seq(from = min.db, to = max.db, by = db.interval)
v.ber <- numeric(0)
perm <- TurboGetPermutation(msg.length, coder, permutation.type, permutation.args)
total.errors <- 0
total.iterations <- length(v.db) * iterations.per.db
print("Turbo Simulation")
progress.bar <- txtProgressBar(min = 0, max = total.iterations, style = 3)
progress.counter <- 0
for (db in v.db) {
for (i in 1 : iterations.per.db) {
# create message
message <- sample(c(0,1), msg.length, replace = TRUE)
# encode
coded <- TurboEncode(message, perm, coder, punctuation.matrix = punctuation.matrix)
# if punctured then take punctured code
if (!is.null(punctuation.matrix)) {
coded <- coded$punctured
}
# add noise
noisy <- ApplyNoise(coded, db)
# decode
decoded <- TurboDecode(noisy, perm, decode.iterations, coder,
punctuation.matrix = punctuation.matrix)
# vgl decoded & message
decode.errors <- sum(abs(decoded$output.hard - message))
total.errors <- total.errors + decode.errors
progress.counter <- progress.counter + 1
setTxtProgressBar(progress.bar, progress.counter)
}
v.ber <- c(v.ber, total.errors / (msg.length * iterations.per.db))
total.errors <- 0
}
close(progress.bar)
df <- data.frame(db = v.db, ber = v.ber)
if (visualize) {
rmarkdown::render(
system.file("rmd", "Simulation.Rmd", package = "channelcoding"),
output_dir = system.file("pdf", package = "channelcoding"),
output_file = "SimulationTurbo.pdf",
params = list(
turbo = TRUE,
message.length = msg.length,
iterations.per.db = iterations.per.db,
min.db = min.db,
max.db = max.db,
db.interval = db.interval,
permutation = perm,
decode.iterations = decode.iterations,
punctuation = punctuation.matrix,
encoder = coder,
dataframe = df),
encoding = "UTF-8")
rstudioapi::viewer(system.file("pdf", "SimulationTurbo.pdf", package = "channelcoding"))
}
return(df)
}
#' Open the beforehand created visualization PDF files again.
#'
#' With this function it is easy to reopen the PDF files which will be created with
#' \code{\link{TurboEncode}} and \code{\link{TurboDecode}}. The files are stored in the
#' program files of R. (example path: "C:/Program Files/R/R-3.2.4/library/channelcoding/pdf")
#'
#' @param encode Flag to open the encode pdfs.
#' @param punctured Flag to open the decode pdfs.
#' @param simulation Flag to open the simulation pdf.
#'
#' @examples
#' # open encode without punctuation PDF
#' TurboOpenPDF()
#'
#' # open encode with punctuation PDF
#' TurboOpenPDF(punctured = FALSE)
#'
#' # open decode with punctuation PDF
#' TurboOpenPDF(encode = FALSE, punctured = TRUE)
#'
#' # open decode without punctuation PDF
#' TurboOpenPDF(encode = FALSE)
#'
#' # open simulation PDF
#' TurboOpenPDF(simulation = TRUE)
#'
#' @export
TurboOpenPDF <- function(encode = TRUE, punctured = FALSE, simulation = FALSE) {
if (simulation) {
path <- system.file("pdf", "SimulationTurbo.pdf", package = "channelcoding")
} else {
if (encode) {
if (punctured) {
path <- system.file("pdf", "TurboEncodePunctured.pdf", package = "channelcoding")
} else {
path <- system.file("pdf", "TurboEncode.pdf", package = "channelcoding")
}
} else {
if (punctured) {
path <- system.file("pdf", "TurboDecodePunctured.pdf", package = "channelcoding")
} else {
path <- system.file("pdf", "TurboDecode.pdf", package = "channelcoding")
}
}
}
if (path != "") {
rstudioapi::viewer(path)
} else {
warning("File does not exists!")
}
}
DaniWi/Channelcoding documentation built on May 6, 2019, 1:23 p.m.
R Package Documentation
Browse R Packages
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Note that we can't provide technical support on individual packages. You should contact the package authors for that.
# turbo_code_rcpp.R
#
# interface for turbo codes
# provided functions:
# - TurboEncode
# - TurboDecode
# - TurboGetpermutation
# - TurboGetPunctuationMatrix
# - TurboSimutlation
# - TurboOpenPDF
#' Encode a message with the turbo-code.
#'
#' This functions takes a message and encode it with the turbo-code procedure. The message
#' will be encoded in 2 identical systematic encoder, but before the message will be encoded in the encoder 2
#' the message will be permutated with an interleaver. To increase the minimal distance between 2 code words
#' the interleaver is needed. The systematic encoder must have 2 exists and it must be
#' an systematic encoder which means that the input is redirected directly to the output.
#' Because of the systematic encoders the original message must be transmitted only once, so
#' this procedure reduces the code rate of the whole encoder. After the 2 encoders the
#' resulting encoded messages are interleaved into one stream and transmitted to the exit.
#' Only one exit of the systematic encoder will be used, so the index of the output can be
#' determined. The punctuation matrix removes all bits where the matrix is zero, so the
#' code rate is increased.
#'
#' @author Witsch Daniel
#'
#' @param message Message which will be encoded.
#' @param permutation.vector Permutation vector which will be created with \code{\link{TurboGetPermutation}}.
#' @param coder.info Coder which will be created with \code{\link{ConvGenerateEncoder}} or \code{\link{ConvGenerateRscEncoder}}.
#' @param parity.index Index to decide which exit of the coder will be used for the encoding (>1).
#' Default value is always the last exit of the coder.
#' @param punctuation.matrix Punctuation matrix to puncture the output, will be created with \code{\link{TurboGetPunctuationMatrix}}.
#' @param visualize Flag to decide whether to create a visualization pdf or not.
#'
#' @return Encoded message, will be a list if the output was punctured (list with original and punctured).
#'
#' @examples
#' input <- c(1,0,1,1,0)
#'
#' #default coder and permutation vector
#' message.encoded <- TurboEncode(input)
#' print(message.encoded)
#'
#' #custom coder and permutation vector
#' coder <- ConvGenerateRscEncoder(2, 2, c(5, 7))
#' perm <- TurboGetPermutation(length(input), coder, "RANDOM")
#' message.encoded <- TurboEncode(input, perm, coder)
#' print(message.encoded)
#'
#' #encoding with punctuation matrix
#' punct <- TurboGetPunctuationMatrix(c(1,1,0,1,0,1))
#' message.encoded.punct <- TurboEncode(input, perm, coder, punctuation.matrix = punct)
#' print(message.encoded.punct$original)
#' print(message.encoded.punct$punctured)
#'
#' @export
TurboEncode <-
function(message,
permutation.vector = NULL,
coder.info = NULL,
parity.index = coder.info$N,
punctuation.matrix = NULL,
visualize = FALSE) {
if (is.null(coder.info)) {
warning("Standard-Coder was used! RSC, N=2, M=2, Generators: (5,7)")
coder.info <- ConvGenerateRscEncoder(2,2,c(5,7))
}
if (is.null(permutation.vector)) {
warning("Standard-Permutationvector was used! (PRIMITIVE)")
permutation.vector <- TurboGetPermutation(length(message), coder.info, "PRIMITIVE", list(root=0))
}
#Checks all parameters
stopifnot(length(message) > 0)
CheckCoder(coder.info)
if (any((message != 1)[message != 0])) {
stop("Message should only contain 0 and 1!")
}
if (coder.info$N < 2) {
stop("Coder must have minimum 2 exists!")
}
if (coder.info$rsc != TRUE && coder.info$generators[1] != (2 ^ coder.info$M)) {
stop("Coder must be an systematic coder!
(exit 1 must have polynom 2^M or it must be a rescursiv coder)")
}
if (length(permutation.vector) != (length(message) + coder.info$M)) {
stop("Permutation vector has the wrong length!")
}
if (any(is.na(match(0:(length(permutation.vector) - 1), permutation.vector)))) {
stop("Permutation vector has the wrong entries!")
}
if (!is.null(punctuation.matrix) && nrow(punctuation.matrix) != 3) {
stop("Punctuation matrix has the wrong amount of rows,
with turbo codes it has to be 3!")
}
#when parity.index is too high or to low
if (parity.index > coder.info$N || parity.index < 0) {
parity.index = coder.info$N
}
#first coder with termination
parity.1 <- ConvEncode(message, coder.info, TRUE)
#extract original message with termination bits from parity
temp.index <- c(rep(FALSE, 0), TRUE, rep(FALSE, coder.info$N - 1))
code.orig <- parity.1[temp.index]
#permutate original message with termination (mapping important!!)
code.orig.01 <- as.numeric(code.orig < 0)
code.perm <- as.numeric(code.orig[permutation.vector + 1] < 0)
#second coder without termination
parity.2 <- ConvEncode(code.perm, coder.info, FALSE)
#extract parity bits from the output messages
temp.index <- c(rep(FALSE, parity.index - 1), TRUE, rep(FALSE, coder.info$N - parity.index))
parity.1 <- parity.1[temp.index]
parity.2 <- parity.2[temp.index]
code.result <- Interleave(code.orig, parity.1, parity.2)
if (!is.null(punctuation.matrix)) {
#puncture the output
code.punct <- PunctureCode(code.result, punctuation.matrix)
}
if (visualize) {
if (length(message) > 10) {
warning("Maybe not the whole informations could be visualized!")
}
if (!is.null(punctuation.matrix)) {
rmarkdown::render(
system.file("rmd", "TurboEncodePunctured.Rmd", package = "channelcoding"),
output_dir = system.file("pdf", package = "channelcoding"),
params = list(
orig = code.orig.01,
interl = code.perm,
parity1 = parity.1,
parity2 = parity.2,
multipl = code.result,
result = code.punct,
permutation = permutation.vector,
punctuation = punctuation.matrix,
encoder = coder.info),
encoding = "UTF-8")
rstudioapi::viewer(system.file("pdf", "TurboEncodePunctured.pdf", package = "channelcoding"))
} else {
rmarkdown::render(
system.file("rmd", "TurboEncode.Rmd", package = "channelcoding"),
output_dir = system.file("pdf", package = "channelcoding"),
params = list(
orig = code.orig.01,
interl = code.perm,
parity1 = parity.1,
parity2 = parity.2,
result = code.result,
permutation = permutation.vector,
encoder = coder.info),
encoding = "UTF-8")
rstudioapi::viewer(system.file("pdf", "TurboEncode.pdf", package = "channelcoding"))
}
}
if (!is.null(punctuation.matrix)) {
return(list(original = code.result, punctured = code.punct))
} else {
return(code.result)
}
}
#' Decode a code which is encoded with the turbo-code.
#'
#' The code will be decoded with the turbo-code procedure. The given coder must be an
#' systematic coder and should have at least 2 exits. To decide which exit is used, the user
#' can decide this with the parameter index. The principle of turbo decoding is that
#' the decoding is a iterative method, so code will be passed through the decoder multiple times.
#' With the parameter iteration you can decide how often the decoders are passed through.
#' After each iteration the result should be better and the result of the last iteration will
#' be used in the next iteration as input values. The exact signal level of the input will be used
#' as input in the first iteration. When punctuation was used during encoding it is important
#' that the same punctuation is given in the decoding because all bits which are deleted can now
#' be inserted again.
#'
#' @author Witsch Daniel
#'
#' @param code Code which will be decoded to the original message.
#' @param permutation.vector Permutation vector which will be created with \code{\link{TurboGetPermutation}}.
#' @param iterations Amount of decoding iterations.
#' @param coder.info Coder which will be created with \code{\link{ConvGenerateEncoder}} or \code{\link{ConvGenerateRscEncoder}}.
#' @param parity.index Index to decide which exit of the coder will be used for the encoding (>1).
#' Default value is always the last exit of the coder.
#' @param punctuation.matrix Punctuation matrix to puncture the output, will be created with \code{\link{TurboGetPunctuationMatrix}}.
#' @param visualize Flag to decide whether to create a visualization pdf or not.
#'
#' @return Decoded message, will be a list (soft and hard values).
#'
#' @examples
#' input <- c(1,0,1,1,0)
#'
#' #default coder and permutation vector
#' message.encoded <- TurboEncode(input)
#' result <- TurboDecode(message.encoded, iterations = 5)
#' print(result)
#'
#' #custom coder and permutation vector
#' coder <- ConvGenerateRscEncoder(2, 2, c(5, 7))
#' perm <- TurboGetPermutation(length(input), coder, "RANDOM")
#' message.encoded <- TurboEncode(input, perm, coder)
#' result <- TurboDecode(message.encoded, perm, 5, coder)
#' print(result)
#'
#' #decoding with punctuation matrix
#' punct <- TurboGetPunctuationMatrix(c(1,1,0,1,0,1))
#' message.encoded.punct <- TurboEncode(input, perm, coder, punctuation.matrix = punct)
#' result <- TurboDecode(message.encoded.punct$punctured, perm, 5, coder, punctuation.matrix = punct)
#' print(result)
#'
#' @export
TurboDecode <-
function(code,
permutation.vector = NULL,
iterations = 1,
coder.info = NULL,
parity.index = coder.info$N,
punctuation.matrix = NULL,
visualize = FALSE) {
if (!is.numeric(code) || !is.vector(code)) {
stop("Code was not a numeric vector! Check the code parameter!")
}
if (is.null(coder.info)) {
warning("Standard-Coder was used! RSC, N=2, M=2, Generators: (5,7)")
coder.info <- ConvGenerateRscEncoder(2,2,c(5,7))
}
#Checks all parameters
stopifnot(length(code) > 0, iterations > 0)
CheckCoder(coder.info)
if (coder.info$N < 2) {
stop("Coder must have minimum 2 exists!")
}
if (coder.info$rsc != TRUE && coder.info$generators[1] != (2 ^ coder.info$M)) {
stop("Coder must be an systematic coder!
(exit 1 must have polynom 2^M or it must be a rescursiv coder)")
}
if (!is.null(permutation.vector) && any(is.na(match(0:(length(permutation.vector) - 1), permutation.vector)))) {
stop("Permutation vector has the wrong entries!")
}
if (!is.null(punctuation.matrix) && nrow(punctuation.matrix) != 3) {
stop("Punctuation matrix has the wrong amount of rows,
with turbo codes it has to be 3!")
}
#when parity.index is too high or to low
if (parity.index > coder.info$N || parity.index < 0) {
parity.index = coder.info$N
}
#Punctuation
if (!is.null(punctuation.matrix)) {
#insert missing bits from punctuation
code.with.punct <- InsertPunctuationBits(code, punctuation.matrix)
} else {
code.with.punct <- code
}
#create the default permutation.vector
if (is.null(permutation.vector)) {
warning("Standard-Permutationvector was used! (PRIMITIVE)")
permutation.vector <- TurboGetPermutation(length(code.with.punct) / 3 - coder.info$M, coder.info, "PRIMITIVE", list(root=0))
}
#Check length of input(with inserted bits) and permutation.vector
if ((length(code.with.punct) %% 3) != 0) {
if (!is.null(punctuation.matrix)) {
stop("Mistake during depunctation!")
}
stop("Code has the wrong length! (Code is maybe punctuated)")
}
if (length(permutation.vector) != (length(code.with.punct) / 3)) {
stop("Permutation vector has the wrong length!")
}
#parse original parts of the code from input code
code.length <- length(code.with.punct) / 3
code.orig <- Deinterleave(code.with.punct, 1)
parity.1 <- Deinterleave(code.with.punct, 2)
parity.2 <- Deinterleave(code.with.punct, 3)
#decode message (c-function)
decoded <-
c_turbo_decode(
code.orig,
parity.1,
parity.2,
permutation.vector,
iterations,
coder.info$N,
coder.info$M,
coder.info$prev.state,
coder.info$output,
parity.index
)
#delete termination bits from result
output.soft <- head(decoded$soft.output, code.length - coder.info$M)
output.hard <- head(decoded$hard.output, code.length - coder.info$M)
message.decoded <- list(output.soft = output.soft, output.hard = output.hard)
if (visualize) {
if (length(output.hard) > 10 || iterations > 10) {
warning("Maybe not the whole informations could be visualized!")
}
if (!is.null(punctuation.matrix)) {
rmarkdown::render(
system.file("rmd", "TurboDecodePunctured.Rmd", package = "channelcoding"),
output_dir = system.file("pdf", package = "channelcoding"),
params = list(
code = code,
punctured = code.with.punct,
orig = code.orig,
parity1 = parity.1,
parity2 = parity.2,
origI = decoded$disp.info$origI,
decode1 = decoded$disp.info$decode1,
decode1I = decoded$disp.info$decode1I,
decode2Back = head(decoded$disp.info$decode2Back, iterations - 1),
decode2IBack = head(decoded$disp.info$decode2IBack, iterations - 1),
decode2 = tail(decoded$disp.info$decode2Back, 1)[[1]],
decode2I = tail(decoded$disp.info$decode2IBack, 1)[[1]],
tempResultSoft = decoded$disp.info$tempResultSoft,
tempResultHard = decoded$disp.info$tempResultHard,
result = message.decoded,
iterations = iterations,
permutation = permutation.vector,
punctuation = punctuation.matrix,
encoder = coder.info),
encoding = "UTF-8")
rstudioapi::viewer(system.file("pdf", "TurboDecodePunctured.pdf", package = "channelcoding"))
} else {
rmarkdown::render(
system.file("rmd", "TurboDecode.Rmd", package = "channelcoding"),
output_dir = system.file("pdf", package = "channelcoding"),
params = list(
code = code,
orig = code.orig,
parity1 = parity.1,
parity2 = parity.2,
origI = decoded$disp.info$origI,
decode1 = decoded$disp.info$decode1,
decode1I = decoded$disp.info$decode1I,
decode2Back = head(decoded$disp.info$decode2Back, iterations - 1),
decode2IBack = head(decoded$disp.info$decode2IBack, iterations - 1),
decode2 = tail(decoded$disp.info$decode2Back, 1)[[1]],
decode2I = tail(decoded$disp.info$decode2IBack, 1)[[1]],
tempResultSoft = decoded$disp.info$tempResultSoft,
tempResultHard = decoded$disp.info$tempResultHard,
result = message.decoded,
iterations = iterations,
permutation = permutation.vector,
encoder = coder.info),
encoding = "UTF-8")
rstudioapi::viewer(system.file("pdf", "TurboDecode.pdf", package = "channelcoding"))
}
}
return(message.decoded)
}
#' Function to generate a permutation vector.
#'
#' This function is a helper function which helps the user to create different permutation
#' vectors. With the argument \code{type} the user can choose one of 6 different interleaver types.
#' Some interleaver need additional informations in the \code{args} argument.
#'
#'
#' \itemize{
#' \item RANDOM: Creates a random permutation vector. No arguments in \code{args}.
#' \item PRIMITIVE: Shift the initial vector (\code{c(1,2,3,...)}) so that the \code{args$root}
#' value is the index of the 1.
#' \item CYCLIC: Creates a initial matrix with the arguments \code{args$cols}, \code{args$rows}
#' and shift each row of the matrix by the index of the row multiplied by the \code{args$distance}.
#' The resulting permutation vector is read out from top to bottom from each column of the matrix.
#' \item BLOCK: This is a type of interleaver in which the bits are read in from left to right in each row from the matrix
#' and read out from top to bottom each column. With the arguments \code{args$cols}, \code{args$rows}
#' the user can change the matrix size.
#' \item HELICAL: This is a type of interleaver in which the bits are read in from left to right in each row from the matrix
#' and read out from left top to bottom right. When the last row of the matrix is arrived
#' then the next bit is read out from the first row but from the next column. With the arguments \code{args$cols}, \code{args$rows}
#' the user can change the matrix size.
#' \item DIAGNOAL: The difference to the HELICAL interleaver is that when the last row is arrived
#' the next bit is in the first row and the first unused column. With the arguments \code{args$cols}, \code{args$rows}
#' the user can change the matrix size.
#' }
#'
#' @param message.length Length of message which will be encoded.
#' @param coder.info Coder which will be used for encoding and decoding.
#' @param type Type of the interleaver, possibilities: RANDOM, PRIMITIVE, CYCLIC, BLOCK
#' HELICAL, DIAGONAL.
#' @param args Arguments for some interleaver. (must be a list)
#' @param visualize Flag to visualize the resulting permutation matrix/vector.
#'
#' @return Created permutation vector.
#'
#' @examples
#' input <- c(1,0,1,1,0,1)
#' coder <- ConvGenerateRscEncoder(2, 2, c(5, 7))
#'
#' #RANDOM
#' permutation <- TurboGetPermutation(length(input), coder, "RANDOM")
#'
#' #PRIMITIV
#' permutation <- TurboGetPermutation(length(input), coder, "PRIMITIVE", list(root=2))
#'
#' #CYCLIC
#' permutation <- TurboGetPermutation(length(input), coder, "CYCLIC", list(cols=2, rows=4, distance=2))
#'
#' #BLOCK
#' permutation <- TurboGetPermutation(length(input), coder, "BLOCK", list(cols=2, rows=4))
#'
#' #HELICAL
#' permutation <- TurboGetPermutation(length(input), coder, "HELICAL", list(cols=2, rows=4))
#'
#' #DIAGONAL
#' permutation <- TurboGetPermutation(length(input), coder, "DIAGONAL", list(cols=2, rows=4))
#'
#' @export
TurboGetPermutation <- function(message.length,
coder.info,
type = "RANDOM",
args = NULL,
visualize = FALSE) {
stopifnot(message.length > 0)
CheckCoder(coder.info)
if (!is.character(type)) {
stop("Type must be an string!")
}
switch(type,
RANDOM = {
interleaver <- sample(c(0:(message.length + coder.info$M - 1)))
if (visualize) {
print(paste("Interleaver-Vector: ", type))
print(interleaver)
}
return(interleaver)
},
PRIMITIVE = {
if (is.null(args$root)) {
stop("Argument args$root was not set!")
}
N <- message.length + coder.info$M - 1
init <- c(0:N)
interleaver <- (init - args$root) %% (N + 1)
if (visualize) {
print(paste("Interleaver-Vector: ", type))
print(interleaver)
}
return(interleaver)
},
CYCLIC = {
if (is.null(args$rows) |
is.null(args$cols) | is.null(args$distance)) {
stop("Argumente (args) was not set correctly!")
}
rows <- args$rows
cols <- args$cols
if (rows * cols != (message.length + coder.info$M)) {
stop("Length of input does not match the amount of rows and columns!")
}
N <- rows * cols
init <- matrix(c(0:(N - 1)), nrow = rows, byrow = FALSE)
i <- 0
interleaver <-
t(apply(init, 1,
function(x) {
temp <- Shift(x, args$distance * (i))
i <<- i + 1
return(temp)
}
))
if (visualize) {
print("Initial-Matrix")
print(init)
print(paste("Interleaver-Matrix: ", type))
print(interleaver)
}
return(as.vector(interleaver))
},
BLOCK = {
if (is.null(args$rows) | is.null(args$cols)) {
stop("Argumente (args) was not set correctly!")
}
rows <- args$rows
cols <- args$cols
if (rows * cols != (message.length + coder.info$M)) {
stop("Length of input does not match the amount of rows and columns!")
}
N <- rows * cols
init <- matrix(c(0:(N - 1)), nrow = rows, byrow = TRUE)
if (visualize) {
print("Initial-Matrix")
print(init)
print(paste("Interleaver-Vector: ", type))
print(as.vector((init)))
}
return(as.vector((init)))
},
HELICAL = {
if (is.null(args$rows) | is.null(args$cols)) {
stop("Argumente (args) was not set correctly!")
}
rows <- args$rows
cols <- args$cols
if (rows * cols != (message.length + coder.info$M)) {
stop("Length of input does not match the amount of rows and columns!")
}
N <- rows * cols
init <- vector(mode = "numeric", length = N)
i <- 0
interleaver <-
sapply(init, function(x) {
x <- (((i %% cols) + (i * cols)) %% N)
i <<- i + 1
return(x)
})
if (visualize) {
print("Initial-Matrix")
print(matrix(c(0:(N - 1)), nrow = rows, byrow = TRUE))
print(paste("Interleaver-Vector: ", type))
print(interleaver)
}
return(interleaver)
},
DIAGONAL = {
if (is.null(args$rows) | is.null(args$cols)) {
stop("Argumente (args) was not set correctly!")
}
rows <- args$rows
cols <- args$cols
if (rows * cols != (message.length + coder.info$M)) {
stop("Length of input does not match the amount of rows and columns!")
}
N <- rows * cols
init <- vector(mode = "numeric", length = N)
i <- 0
interleaver <-
sapply(init, function(x) {
x <- (i * cols) %% N + (i %/% rows + i %% rows) %% cols
i <<- i + 1
return(x)
})
if (visualize) {
print("Initial-Matrix")
print(matrix(c(0:(N - 1)), nrow = rows, byrow = TRUE))
print(paste("Interleaver-Vector: ", type))
print(interleaver)
}
return(interleaver)
}
)
stop("Type of interleaver (type) was not set correctly!")
}
#' Create a punctuation matrix from a vector.
#'
#' This is a helper function to create a correct punctuation matrix. The punctuation.vector
#' should only contain 0 and 1 and has to be a length which is a multiple of 3. The resulting
#' punctuation matrix should not contain a 0 column because this could cause an error during
#' decoding.
#'
#' @param punctuation.vector Vector which will be mapped to the matrix.
#' @param visualize Flag to visualize the resulting punctuation matrix.
#'
#' @return Punctuation matrix for encoder and decoder.
#'
#' @examples
#' TurboGetPunctuationMatrix(c(1, 1, 0, 1, 0, 1), TRUE)
#'
#' @export
TurboGetPunctuationMatrix <- function(punctuation.vector, visualize = FALSE) {
if (any((punctuation.vector != 1)[punctuation.vector != 0])) {
stop("Invalid punctuation vector! Only values 0/1 are allowed!")
}
if (length(punctuation.vector) %% 3 != 0) {
stop("Wrong length of punctuation vector! Must be a multiple of 3!")
}
mat <- matrix(punctuation.vector, nrow = 3)
if (visualize) {
print("Punctuation-Matrix:")
print(mat)
}
if (any(colSums(mat) == 0)) {
stop("Punctuation matrix should not have a 0 column!")
}
return(mat)
}
#' Function to make a automatic simulation of an coder with different signal/noise ratio.
#'
#' This easy functions makes it possible to compare different coders. The function encode
#' a random message, apply noise to the code and then decode the code. This will be computed
#' many times and after all iterations the bit error rate will be calculated. This procedure
#' is applied to different signal/noise ratios. The result will be printed in a graph, when
#' visualization flag is set to TRUE.
#'
#' @param coder Coder which will be created with \code{\link{ConvGenerateEncoder}} or \code{\link{ConvGenerateRscEncoder}}.
#' @param permutation.type Type of permutation vector.
#' @param permutation.args Arguments to the \code{\link{TurboGetPermutation}} function.
#' @param decode.iterations Amount of decoding iterations inside the turbo decoder.
#' @param msg.length Length of the randomly created message.
#' @param min.db Start value of the signal/noise ratio.
#' @param max.db End value of the signal/noise ration.
#' @param db.interval Interval which will be added to the actual signal/noise ratio after all
#' iterations are applied.
#' @param iterations.per.db Amount of iterations each signal/noise ration step.
#' @param punctuation.matrix Punctuation matrix to puncture the output, will be created with \code{\link{TurboGetPunctuationMatrix}}.
#' @param visualize Flag to decide whether to create a visualization pdf or not.
#'
#' @return DataFrame which contains the bit error rate for each signal/noise ratio step.
#'
#' @examples
#' #all default parameters
#' TurboSimulation()
#'
#' #without punctuation
#' coder <- ConvGenerateRscEncoder(2, 2, c(5, 7))
#' TurboSimulation(coder, "RANDOM", NULL, 5, 10, 0.01, 1, 0.05, 50, NULL, FALSE)
#'
#' @export
TurboSimulation <- function(coder = NULL,
permutation.type = "PRIMITIVE",
permutation.args = list(root=0),
decode.iterations = 5,
msg.length = 100,
min.db = 0.1,
max.db = 2.0,
db.interval = 0.1,
iterations.per.db = 100,
punctuation.matrix = NULL,
visualize = FALSE)
{
stopifnot(decode.iterations > 0, msg.length > 0, iterations.per.db > 0,
min.db > 0, max.db > 0, max.db >= min.db, db.interval > 0)
if (is.null(coder)) {
warning("Standard-Coder was used! RSC, N=2, M=2, Generators: (5,7)")
coder <- ConvGenerateRscEncoder(2,2,c(5,7))
}
v.db <- seq(from = min.db, to = max.db, by = db.interval)
v.ber <- numeric(0)
perm <- TurboGetPermutation(msg.length, coder, permutation.type, permutation.args)
total.errors <- 0
total.iterations <- length(v.db) * iterations.per.db
print("Turbo Simulation")
progress.bar <- txtProgressBar(min = 0, max = total.iterations, style = 3)
progress.counter <- 0
for (db in v.db) {
for (i in 1 : iterations.per.db) {
# create message
message <- sample(c(0,1), msg.length, replace = TRUE)
# encode
coded <- TurboEncode(message, perm, coder, punctuation.matrix = punctuation.matrix)
# if punctured then take punctured code
if (!is.null(punctuation.matrix)) {
coded <- coded$punctured
}
# add noise
noisy <- ApplyNoise(coded, db)
# decode
decoded <- TurboDecode(noisy, perm, decode.iterations, coder,
punctuation.matrix = punctuation.matrix)
# vgl decoded & message
decode.errors <- sum(abs(decoded$output.hard - message))
total.errors <- total.errors + decode.errors
progress.counter <- progress.counter + 1
setTxtProgressBar(progress.bar, progress.counter)
}
v.ber <- c(v.ber, total.errors / (msg.length * iterations.per.db))
total.errors <- 0
}
close(progress.bar)
df <- data.frame(db = v.db, ber = v.ber)
if (visualize) {
rmarkdown::render(
system.file("rmd", "Simulation.Rmd", package = "channelcoding"),
output_dir = system.file("pdf", package = "channelcoding"),
output_file = "SimulationTurbo.pdf",
params = list(
turbo = TRUE,
message.length = msg.length,
iterations.per.db = iterations.per.db,
min.db = min.db,
max.db = max.db,
db.interval = db.interval,
permutation = perm,
decode.iterations = decode.iterations,
punctuation = punctuation.matrix,
encoder = coder,
dataframe = df),
encoding = "UTF-8")
rstudioapi::viewer(system.file("pdf", "SimulationTurbo.pdf", package = "channelcoding"))
}
return(df)
}
#' Open the beforehand created visualization PDF files again.
#'
#' With this function it is easy to reopen the PDF files which will be created with
#' \code{\link{TurboEncode}} and \code{\link{TurboDecode}}. The files are stored in the
#' program files of R. (example path: "C:/Program Files/R/R-3.2.4/library/channelcoding/pdf")
#'
#' @param encode Flag to open the encode pdfs.
#' @param punctured Flag to open the decode pdfs.
#' @param simulation Flag to open the simulation pdf.
#'
#' @examples
#' # open encode without punctuation PDF
#' TurboOpenPDF()
#'
#' # open encode with punctuation PDF
#' TurboOpenPDF(punctured = FALSE)
#'
#' # open decode with punctuation PDF
#' TurboOpenPDF(encode = FALSE, punctured = TRUE)
#'
#' # open decode without punctuation PDF
#' TurboOpenPDF(encode = FALSE)
#'
#' # open simulation PDF
#' TurboOpenPDF(simulation = TRUE)
#'
#' @export
TurboOpenPDF <- function(encode = TRUE, punctured = FALSE, simulation = FALSE) {
if (simulation) {
path <- system.file("pdf", "SimulationTurbo.pdf", package = "channelcoding")
} else {
if (encode) {
if (punctured) {
path <- system.file("pdf", "TurboEncodePunctured.pdf", package = "channelcoding")
} else {
path <- system.file("pdf", "TurboEncode.pdf", package = "channelcoding")
}
} else {
if (punctured) {
path <- system.file("pdf", "TurboDecodePunctured.pdf", package = "channelcoding")
} else {
path <- system.file("pdf", "TurboDecode.pdf", package = "channelcoding")
}
}
}
if (path != "") {
rstudioapi::viewer(path)
} else {
warning("File does not exists!")
}
}
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