Package: comm
Equalize using maximum likelihood sequence estimation
The MLSEEqualizer
object uses the Viterbi algorithm
to equalize a linearly modulated signal through a dispersive channel.
The object processes input frames and outputs the maximum likelihood
sequence estimate (MLSE) of the signal. This processing uses an estimate
of the channel modeled as a finite impulse response (FIR) filter.
To equalize a linearly modulated signal and output the maximum likelihood sequence estimate:
Define and set up your maximum likelihood sequence estimate equalizer object. See Construction.
Call step
to equalize a linearly
modulated signal and output the maximum likelihood sequence estimate
according to the properties of comm.MLSEEqualizer
.
The behavior of step
is specific to each object in
the toolbox.
Note:
Starting in R2016b, instead of using the 
H = comm.MLSEEqualizer
creates a maximum
likelihood sequence estimation equalizer (MLSEE) System object, H
.
This object uses the Viterbi algorithm and a channel estimate to equalize
a linearly modulated signal that has been transmitted through a dispersive
channel.
H = comm.MLSEEqualizer(
creates
an MLSEE object, Name
,Value
)H
, with each specified property
set to the specified value. You can specify additional namevalue
pair arguments in any order as (Name1
,Value1
,...,NameN
,ValueN
).
H = comm.MLSEEqualizer(CHANNEL,
creates
an MLSEE object, Name
,Value
)H
. This object has the Channel
property
set to CHANNEL
, and the other specified properties
set to the specified values.

Source of channel coefficients Specify the source of the channel coefficients as one of 

Channel coefficients Specify the channel as a numeric, column vector containing the
coefficients of an FIR filter. The default is 

Input signal constellation Specify the constellation of the input modulated signal as a
complex vector. The default is 

Traceback depth of Viterbi algorithm Specify the number of trellis branches (the number of symbols),
the Viterbi algorithm uses to construct each traceback path. The default
is 

Termination method of Viterbi algorithm Specify the termination method of the Viterbi algorithm as one
of 

Enable equalizer reset input Set this property to 

Source of preamble Specify the source of the preamble that is expected to precede
the input signal. Choose from 

Preamble that precedes input signals Specify a preamble that is expected to precede the data in the
input signal as an integer, row vector. The default is 

Source of postamble Specify the source of the postamble that is expected to follow
the input signal. Choose from 

Postamble that follows input signals Specify a postamble that is expected to follow the data in the
input signal as an integer row vector. The default is 

Number of samples per symbol Specify the number of samples per symbol in the input signal
as an integer scalar value. The default is 
clone  Create MLSEE object with same property values 
getNumInputs  Number of expected inputs to step method 
getNumOutputs  Number of outputs from step method 
isLocked  Locked status for input attributes and nontunable properties 
release  Allow property value and input characteristics changes 
reset  Reset states of MLSEE object 
step  Equalize using maximum likelihood sequence estimation 
This object implements the algorithm, inputs, and outputs described on the MLSE Equalizer block reference page. The object properties correspond to the block parameters.