(To be removed) Construct linear equalizer object
lineareq will be removed in a future release. Use comm.LinearEqualizer instead.
eqobj = lineareq(nweights,alg)
eqobj = lineareq(nweights,alg,sigconst)
eqobj = lineareq(nweights,alg,sigconst,nsamp)
The lineareq function creates an equalizer object that you can
use with the equalize function to equalize a
signal. To learn more about the process for equalizing a signal, see Equalization.
eqobj = lineareq(nweights,alg) constructs
a symbol-spaced linear equalizer object. The equalizer has nweights
complex weights, which are initially all zeros. alg describes the
adaptive algorithm that the equalizer uses; you should create alg
using any of these functions: lms, signlms, normlms, varlms, rls, or cma. The signal constellation of the desired output is [-1
1], which corresponds to binary phase shift keying (BPSK).
eqobj = lineareq(nweights,alg,sigconst)
specifies the signal constellation vector of the desired output.
eqobj = lineareq(nweights,alg,sigconst,nsamp)
constructs a fractionally spaced linear equalizer object. The equalizer has
nweights complex weights spaced at T/nsamp,
where T is the symbol period and nsamp is a
positive integer. nsamp = 1 corresponds to a symbol-spaced
equalizer.
The table below describes the properties of the linear equalizer object. To learn how to view or change the values of a linear equalizer object, see Equalization.
Tip
To initialize or reset the equalizer object eqobj, enter
reset(eqobj).
| Property | Description |
|---|---|
EqType | Fixed value, 'Linear Equalizer' |
AlgType | Name of the adaptive algorithm represented by
alg |
nWeights | Number of weights |
nSampPerSym | Number of input samples per symbol (equivalent to
nsamp input argument). This value relates to
both the equalizer structure (see the use of K in Equalization) and an assumption about the
signal to be equalized. |
RefTap (except for CMA equalizers) | Reference tap index, between 1 and nWeights.
Setting this to a value greater than 1 effectively delays the
reference signal and the output signal by
RefTap-1 with respect to the equalizer's
input signal. |
SigConst | Signal constellation, a vector whose length is typically a power of 2 |
Weights | Vector of complex coefficients. This is the set of wi values in the schematic in Equalization. |
WeightInputs | Vector of tap weight inputs. This is the set of ui values in the schematic in Equalization. |
ResetBeforeFiltering | If 1, each call to
equalize resets the state of
eqobj before equalizing. If
0, the equalization process maintains
continuity from one call to the next. |
NumSamplesProcessed | Number of samples the equalizer processed since the last reset.
When you create or reset eqobj, this property
value is 0. |
Properties specific to the adaptive algorithm represented by
alg | See reference page for the adaptive algorithm function that
created alg: lms, signlms,
normlms,
varlms, rls, or cma. |
If you change nWeights, MATLAB maintains consistency in the
equalizer object by adjusting the values of the properties listed below.
| Property | Adjusted Value |
|---|---|
Weights | zeros(1,nWeights) |
WeightInputs | zeros(1,nWeights) |
StepSize (Variable-step-size LMS
equalizers) | InitStep*ones(1,nWeights) |
InvCorrMatrix (RLS equalizers) | InvCorrInit*eye(nWeights) |