comm.MLSEEqualizer
Equalize using maximum likelihood sequence estimation
Description
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 ofcomm.MLSEEqualizer
. The behavior ofstep
is specific to each object in the toolbox.
Note
Starting in R2016b, instead of using the step
method
to perform the operation defined by the System object™, you can
call the object with arguments, as if it were a function. For example, y
= step(obj,x)
and y = obj(x)
perform
equivalent operations.
Construction
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 name-value
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.
Properties
|
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 |
Methods
step | Equalize using maximum likelihood sequence estimation |
Examples
Algorithms
This object implements the algorithm, inputs, and outputs described on the MLSE Equalizer block reference page. The object properties correspond to the block parameters.