communications

Digital Communications, Error Correcting Codes (Channel Code), Source Code functions, Modulation and Galois Fields

Select category:

Random Signals

awgn
Add white Gaussian noise to a voltage signal.
biterr
Compares two matrices and returns the number of bit errors and the bit error rate.
eyediagram
Plot the eye-diagram of a signal.
randerr
Generate a matrix of random bit errors.
randint
Generate a matrix of random binary numbers.
randsrc
Generate a matrix of random symbols.
scatterplot
Display the scatter plot of a signal.
symerr
Compares two matrices and returns the number of symbol errors and the symbol error rate.
wgn
Returns a M-by-N matrix Y of white Gaussian noise.
bsc
Send DATA into a binary symmetric channel with probability P of error one each symbol.

Source Coding

compand
Compresses and expanding the dynamic range of a signal using a mu-law or or A-law algorithm.
dpcmdeco
Decode using differential pulse code modulation (DPCM).
dpcmenco
Encode using differential pulse code modulation (DPCM).
dpcmopt
Optimize the DPCM parameters and codebook.
huffmandeco
Decode signal encoded by 'huffmanenco'.
huffmandict
Builds a Huffman code, given a probability list.
huffmanenco
Returns the Huffman encoded signal using DICT.
lloyds
Optimize the quantization table and codes to reduce distortion.
lz77deco
Lempel-Ziv 77 source algorithm decoding implementation.
lz77enco
Lempel-Ziv 77 source algorithm implementation.
quantiz
Quantization of an arbitrary signal relative to a partitioning.
shannonfanodict
Returns the code dictionary for source using Shannon-Fano algorithm.
shannonfanoenco
Returns the Shannon-Fano encoded signal using DICT.
shannonfanodeco
Returns the original signal that was Shannon-Fano encoded.
rleenco
Returns run-length encoded MESSAGE.
rledeco
Returns decoded run-length MESSAGE.
riceenco
Returns the Rice encoded signal using K or optimal K .
ricedeco
Returns the Rice decoded signal vector using CODE and K.
fiboenco
Returns the cell-array of encoded Fibonacci value from the column vectors NUM.
fibodeco
Returns the decoded Fibonacci value from the binary vectors CODE.
fibosplitstream
Returns the split data stream at the word boundaries.
golombenco
Returns the Golomb coded signal as cell array.
golombdeco
Returns the Golomb decoded signal vector using CODE and M.

Block Interleavers

intrlv
Interleaved elements of DATA according to ELEMENTS.
helscanintrlv
NROWS-by-NCOLS.
matintrlv
Interleaved elements of DATA with a temporary matrix of size NROWS-by-NCOLS.
randintrlv
Interleaves elements of DATA with a random permutation.
deintrlv
Restore elements of DATA according to ELEMENTS.
matdeintrlv
Restore elements of DATA with a temporary matrix of size NROWS-by-NCOLS.
randdeintrlv
Restore elements of DATA with a random permutation.

Block Coding

bchdeco
Not implemented.
bchenco
Not implemented.
bchpoly
Calculates the generator polynomials for a BCH coder.
convenc
Encode the binary vector MSG with the convolutional encoder described by the trellis structure T.
cyclgen
Not implemented.
cyclpoly
Not implemented.
decode
Top level block decoder.
encode
Top level block encoder.
egolaydec
Decode Extended Golay code.
egolayenc
Encode with Extended Golay code.
egolaygen
Extended Golay code generator matrix.
gen2par
Converts binary generator matrix GEN to the parity check matrix PAR and visa-versa.
hammgen
Produce the parity check and generator matrices of a Hamming code.
reedmullerdec
Decode the received code word VV using the RM-generator matrix G, of order R, M, returning the code-word C.
reedmullerenc
Definition type construction of Reed-Muller code, of order R, length 2^M.
reedmullergen
Definition type construction of Reed-Muller code, of order R, length 2^M.
rsgenpoly
Creates a generator polynomial for a Reed-Solomon coding with message length of K and codelength of N.
rsdec
Not implemented.
rsdecof
Decodes an ASCII file using a Reed-Solomon coder.
rsenc
Not implemented.
rsencof
Encodes an ASCII file using a Reed-Solomon coder.
systematize
Given G, extract P parity check matrix.
syndtable
Not implemented.

Modulations

ademodce
Baseband demodulator for analog signals.
amodce
Baseband modulator for analog signals.
ammod
Creates the AM modulation of the amplitude signal X with carrier frequency FC.
amdemod
Creates the AM demodulation of the signal S sampled at frequency FS with carrier frequency FC.
apkconst
Plots a ASK/PSK signal constellation.
bin2gray
Creates a Gray encoded data Y with the same size as input X
demodmap
Demapping of an analog signal to a digital signal.
fmmod
Creates the FM modulation S of the message signal M with carrier frequency FC.
fmdemod
Creates the FM demodulation of the signal S sampled at frequency FS with carrier frequency FC.
genqammod
Modulates an information sequence of integers X in the range '[0 ...
genqamdemod
Not implemented.
modmap
Mapping of a digital signal to an analog signal.
pamdemod
Demodulates a pulse amplitude modulated signal X into an information sequence of integers in the range '[0 ...
pammod
Modulates an information sequence of integers X in the range '[0 ...
pskdemod
Demodulates a complex-baseband phase shift keying modulated signal into an information sequence of integers in the range '[0 ...
pskmod
Modulates an information sequence of integers X in the range '[0 ...
qaskdeco
Demaps an analog signal using a square QASK constellation.
qaskenco
Map a digital signal using a square QASK constellation.
qammod
Create the QAM modulation of X with a size of alphabet M using a given SYMORDER.
qamdemod
Create the QAM demodulation of x with a size of alphabet m.
ssbmod
Creates the SSB modulation of the amplitude signal X with carrier frequency FC , sampling frequency FS initial phase : PHI and specified band : BAND initial phase : PHI and specified band : BAND ar...
ssbdemod
Creates the SSB demodulation of the signal S with carrier frequency FC, sampling frequency FS initial phase PHI and a standard 5th order low pass butterworth filter [b a] = butter (5, fc .* 2 ./ fs...

Channel Filters

rcosfir
Implements a cosine filter or root cosine filter impulse response

Galois Fields of Even Characteristic

all
For a vector argument, return true (logical 1) if all elements of the vector are nonzero.
any
For a vector argument, return true (logical 1) if any element of the vector is nonzero.
cosets
Finds the elements of GF(2^M) with primitive polynomial PRIM, that share the same minimum polynomial.
conv
Convolve two vectors A and B.
convmtx
If A is a column vector and X is a column vector of length N, then
deconv
Deconvolve two vectors (polynomial division).
det
Compute the determinant of A.
dftmtx
Compute the N-by-N Fourier transformation matrix.
diag
Return a diagonal matrix with vector V on diagonal K.
exp
Compute 'e^x' for each element of X.
gf
Not implemented.
fft
Compute the discrete Fourier transform of X using a Fast Fourier Transform (FFT) algorithm.
filter
Apply a 1-D digital filter to the data X.
gftable
This function exists for compatibility with matlab.
gfweight
Calculate the minimum weight or distance of a linear block code.
ifft
Compute the inverse discrete Fourier transform of X using a Fast Fourier Transform (FFT) algorithm.
inv
Compute the inverse of the square matrix A.
inverse
Compute the inverse of the square matrix A.
isequal
Return true if all of X1, X2, ... are equal.
log
Compute the natural logarithm, 'ln (X)', for each element of X.
lu
Compute the LU decomposition of A.
prod
Product of elements along dimension DIM.
sqrt
Compute the square root of each element of X.
rank
Compute the rank of matrix A, using the singular value decomposition.
reshape
Return a matrix with the specified dimensions (M, N, ...) whose elements are taken from the matrix A.
roots
Compute the roots of the polynomial C.
sum
Sum of elements along dimension DIM.
sumsq
Sum of squares of elements along dimension DIM.
isempty
Return true if A is an empty matrix (any one of its dimensions is zero).
isgalois
Not implemented.
isprimitive
Not implemented.
length
Return the length of the object A.
minpol
Finds the minimum polynomial for elements of a Galois Field.
polyval
Evaluate the polynomial P at the specified values of X.
primpoly
Not implemented.
size
Return a row vector with the size (number of elements) of each dimension for the object A.

Utility Functions

comms
Manual and test code for the Octave Communications toolbox.
bi2de
Convert bit matrix to a vector of integers
de2bi
Convert a non-negative integer to bit vector.
oct2dec
Convert octal to decimal values.
istrellis
Return true if T is a valid trellis structure.
poly2trellis
Convert convolutional code generator polynomials into trellis form.
vec2mat
Converts the vector V into a C column matrix with row priority arrangement and with the final column padded with the value D to the correct length.
qfunc
Compute the Q function.
qfuncinv
Compute the inverse Q function.

Measurement and Analysis

berconfint
Returns Bit Error Rate, BER, and confidence interval, INTERVAL, for the number of errors R and number of transmitted bits N with a confidence level of LEVEL.
finddelay
Estimate the delay between times series X and time series Y by correlating and finding the peak.

Package: communications