www.gusucode.com > signal 工具箱matlab源码程序 > signal/+fdesign/@interpolator/interpolator.m
classdef (CaseInsensitiveProperties=true) interpolator < fdesign.abstractmultirate2 & dynamicprops
%INTERPOLATOR Construct an interpolator filter designer.
% D = FDESIGN.INTERPOLATOR(L) constructs an interpolator filter designer
% D with an 'InterpolationFactor' of L. If L is not specified, it
% defaults to 2.
%
% D = FDESIGN.INTERPOLATOR(L, RESPONSE) initializes the filter designer
% 'Response' property with RESPONSE. RESPONSE is one of the following
% strings and is not case sensitive:
% 'Nyquist' (default)
% 'Halfband'
% 'Lowpass'
% 'CIC'
% 'CIC Compensator'
% 'Inverse-sinc Lowpass'
% 'Inverse-sinc Highpass'
% 'Highpass'
% 'Hilbert'
% 'Bandpass'
% 'Bandstop'
% 'Differentiator'
% 'Arbitrary Magnitude'
% 'Arbitrary Magnitude and Phase'
% 'Raised Cosine'
% 'Square Root Raised Cosine'
% 'Gaussian'
%
% D = FDESIGN.INTERPOLATOR(L, RESPONSE, SPEC) initializes the filter
% designer 'Specification' property with SPEC. Use SET(D, 'SPECIFICATION')
% to get all available specifications for the response RESPONSE.
%
% Different design and specification types will have different design
% methods available. Use DESIGNMETHODS(D) to get a list of design
% methods available for a given SPEC.
%
% D = FDESIGN.INTERPOLATOR(L, RESPONSE, SPEC, SPEC1, SPEC2, ...)
% initializes the filter designer specifications with SPEC1, SPEC2, etc.
% Use GET(D, 'DESCRIPTION') for a description of SPEC1, SPEC2, etc.
%
% D = FDESIGN.INTERPOLATOR(...,Fs) specifies the sampling frequency (in
% Hz). In this case, all frequency properties are also in Hz.
%
% D = FDESIGN.INTERPOLATOR(...,MAGUNITS) specifies the units for any
% magnitude specification given in the constructor. MAGUNITS can be one
% of the following: 'linear', 'dB', or 'squared'. If this argument is
% omitted, 'dB' is assumed. Note that the magnitude specifications are
% always converted and stored in dB regardless of how they were
% specified.
%
% Some responses have additional constructor inputs. The syntaxes for
% these special cases are listed below:
%
% D = FDESIGN.INTERPOLATOR(L, 'CIC', DD, SPEC, ...) creates a CIC
% interpolator filter designer with the 'InterpolationFactor' property
% set to L, and the 'DifferentialDelay' property set to DD.
%
% D = FDESIGN.INTERPOLATOR(L, 'CIC compensator', DD, N, R, SPEC, ...)
% creates a CIC compensator interpolator filter designer with the
% 'InterpolationFactor' property set to L, the 'DifferentialDelay'
% property set to DD, the 'NumberOfSections' property set to N, and the
% 'CICRateChangeFactor' property set to R. In general, the design method
% implements a filter with a passband response equal to an inverse
% Dirichlet sinc that matches exactly the inverse passband response of a
% CIC filter with a differential delay equal to DD, number of sections
% equal to N, and rate change factor equal to R. When R is not specified
% or is set to 1, the design method implements a filter with a passband
% response equal to an inverse sinc that is an approximation to the true
% inverse passband response of the CIC filter.
%
% D = FDESIGN.INTERPOLATOR(L, PULSESHAPERESP, SPS, SPEC, ...) where
% PULSESHAPERESP equals 'Raised Cosine', 'Square Root Raised Cosine', or
% 'Gaussian', creates a pulse shaping interpolator filter designer with
% the 'InterpolationFactor' property set to L, and the 'SamplesPerSymbol'
% property set to SPS.
%
% % Example #1 - Design a CIC interpolator for a signal sampled at 19200 Hz
% % with a differential delay of two and that attenuates images beyond 50 Hz
% % by at least 80 dB.
% DD = 2; % Differential delay
% Fp = 50; % Passband of interest
% Ast = 80; % Minimum attenuation of alias components in passband
% Fs = 600; % Sampling frequency for input signal
% L = 32; % Interpolation factor
% d = fdesign.interpolator(L,'cic',DD,'Fp,Ast',Fp,Ast,L*Fs);
% hm = design(d,'SystemObject',true);
%
% % Example #2 - Design a minimum-order CIC compensator that interpolates by
% % 4 and pre-compensates for the droop in the passband for the CIC from the
% % previous example.
% Nsecs = hm.NumSections;
% R = hm.InterpolationFactor;
% d = fdesign.interpolator(4,'ciccomp',DD,Nsecs,R,'Fp,Fst,Ap,Ast',50,100,0.1,80,Fs);
% hmc = design(d,'equiripple','SystemObject',true);
% % Analyze filters individually plus compound response
% hfvt = fvtool(hmc,hm,cascade(hmc,hm),'Fs',[Fs,L*Fs,L*Fs],'ShowReference','off');
% legend(hfvt,'CIC pre-compensator','CIC interpolator','Overall response');
%
% % Example #3 - Design a minimum-order Nyquist interpolator using a Kaiser
% % window. Compare to a multistage design.
% L = 15; % Interpolation factor. Also the Nyquist band.
% TW = 0.05; % Normalized transition width
% Ast = 40; % Minimum stopband attenuation in dB
% d = fdesign.interpolator(L,'nyquist',L,TW,Ast);
% hm = design(d,'kaiserwin','SystemObject',true);
% hm2 = design(d,'multistage','SystemObject',true);
% hfvt = fvtool(hm,hm2); legend(hfvt,'Kaiser window','Multistage');
%
% % Example #4 - Design a lowpass interpolator for an interpolation factor of 8.
% % Compare a single-stage equiripple design with multistage designs.
% L = 8; % Interpolation factor;
% d = fdesign.interpolator(L,'lowpass');
% hm1 = design(d,'equiripple','SystemObject',true);
% % Use halfband filters whenever possible
% hm2 = design(d,'multistage','Usehalfbands',true,'SystemObject',true);
% % Use quasi linear-phase IIR halfbands
% hm3 = design(d,'multistage','Usehalfbands',true,'HalfbandDesignMethod','iirlinphase');
% hfvt = fvtool(hm1,hm2,hm3);
% legend(hfvt,'Single-stage equiripple','Multistage','Multistage with IIR halfbands')
%
% See also FDESIGN, FDESIGN/SETSPECS, FDESIGN/DESIGN.
% Copyright 2004-2015 The MathWorks, Inc.
%fdesign.interpolator class
% fdesign.interpolator extends fdesign.abstractmultirate2.
%
% fdesign.interpolator properties:
% MultirateType - Property is of type 'ustring' (read only)
% Fs_in - Property is of type 'mxArray' (read only)
% Fs_out - Property is of type 'mxArray' (read only)
% Response - Property is of type 'interpolator_responses enumeration: {'Nyquist','Halfband','Lowpass','CIC','CIC Compensator','Inverse-sinc Lowpass','Highpass','Hilbert','Differentiator','Bandpass','Bandstop','Arbitrary Magnitude','Arbitrary Magnitude and Phase','Raised Cosine','Square Root Raised Cosine','Gaussian','Inverse-sinc Highpass'}'
% InterpolationFactor - Property is of type 'posint user-defined'
%
% fdesign.interpolator methods:
% butter - Butterworth IIR digital filter design.
% disp - Display this object.
% ellip - Elliptic or Cauer digital filter design.
% get_fs_in - PreGet function for the 'fs_in' property.
% get_fs_out - PreGet function for the 'fs_out' property.
% get_interpolationfactor - PreGet function for the 'interpolationfactor' property.
% getcicconstructor - Get the cicconstructor.
% getdefaultmethod - Get the defaultmethod.
% getratechangefactors - Get the ratechangefactors.
% ifir - Design an interpolated FIR filter.
% multistage - Design a multistage equiripple interpolator.
% nominalgain - Return the nominal gain.
% passbandspecmet - Check whether passband response is within spec.
% set_interpolationfactor - PreSet function for the 'interpolationfactor' property.
% setratechangefactors - Set the ratechangefactors.
% thisdesign - DESIGN
% updatefdesignfactors - Update the current FDesign rate change factors.
% validstructures - Return the valid structures for the design method.
properties (AbortSet, SetObservable, GetObservable)
%INTERPOLATIONFACTOR Property is of type 'posint user-defined'
InterpolationFactor = [];
end
properties (Access=protected, AbortSet, SetObservable, GetObservable)
%PRIVINTERPOLATIONFACTOR Property is of type 'posint user-defined'
privInterpolationFactor = 2;
end
properties (SetObservable, GetObservable)
%RESPONSE Property is of type 'interpolator_responses enumeration: {'Nyquist','Halfband','Lowpass','CIC','CIC Compensator','Inverse-sinc Lowpass','Highpass','Hilbert','Differentiator','Bandpass','Bandstop','Arbitrary Magnitude','Arbitrary Magnitude and Phase','Raised Cosine','Square Root Raised Cosine','Gaussian','Inverse-sinc Highpass'}'
Response
end
methods % constructor block
function this = interpolator(L, DT, varargin)
% this = fdesign.interpolator;
this.MultirateType = 'Interpolator';
this.Response = 'Nyquist';
needsDefaults = true;
if nargin > 0
this.InterpolationFactor = L;
if nargin > 1
if isa(DT, 'fdesign.pulseshaping')
error(message('signal:fdesign:interpolator:interpolator:unsupportedResponse', class( DT )));
end
if isa(DT, 'fdesign.abstracttypewspecs')
this.AllFDesign = copy(DT);
this.CurrentFDesign = [];
[~, DT] = strtok(class(DT), '.');
DT(1) = [];
needsDefaults = false;
end
newresp = mapresponse(this, DT);
if strcmpi(newresp, this.Response)
updatecurrentfdesign(this);
else
this.Response = newresp;
end
end
end
if needsDefaults
multiratedefaults(this.CurrentFDesign, this.InterpolationFactor);
end
setspecs(this, varargin{:});
end % interpolator
end % constructor block
methods
function set.privInterpolationFactor(obj,value)
% User-defined DataType = 'posint user-defined'
obj.privInterpolationFactor = value;
end
%------------------------------------------------------------------------
function value = get.Response(obj)
value = get_response(obj,obj.Response);
end
%------------------------------------------------------------------------
function set.Response(obj,value)
value = validatestring(value,getAllowedStringValues(obj,'Response'),'','Response');
obj.Response = set_response(obj,value);
end
%------------------------------------------------------------------------
function value = get.InterpolationFactor(obj)
value = get_interpolationfactor(obj,obj.InterpolationFactor);
end
%------------------------------------------------------------------------
function set.InterpolationFactor(obj,value)
% User-defined DataType = 'posint user-defined'
validateattributes(value,{'numeric'},{'integer','positive','scalar'}...
,'','InterpolationFactor')
obj.InterpolationFactor = set_interpolationfactor(obj,value);
end
end % set and get functions
methods
function vals = getAllowedStringValues(obj,prop)
if strcmp(prop,'Response')
vals = {'Nyquist',...
'Halfband',...
'Lowpass',...
'CIC',...
'CIC Compensator',...
'Inverse-sinc Lowpass',...
'Highpass',...
'Hilbert',...
'Differentiator',...
'Bandpass',...
'Bandstop',...
'Arbitrary Magnitude',...
'Arbitrary Magnitude and Phase',...
'Raised Cosine',...
'Square Root Raised Cosine',...
'Gaussian',...
'Inverse-sinc Highpass'}';
elseif strcmp(prop,'Specification')
vals = fdesign.interpolator.getspeclist(obj.Response)';
else
vals = {};
end
end
end
methods (Access = protected)
%This function defines the display behavior for the class
%using matlab.mixin.util.CustomDisplay
function propgrp = getPropertyGroups(obj)
propList = get(obj);
cpropList = propstoadd(obj.CurrentFDesign);
fs_indx = find(strcmpi('Fs',cpropList));
if isfield(propList, 'SamplesPerSymbol')
propList = reorderstructure(propList, 'MultirateType','Response', ...
'InterpolationFactor', 'SamplesPerSymbol','Specification', ...
cpropList{1:fs_indx-1},'Fs','Fs_in','Fs_out',cpropList{fs_indx:end});
else
propList = reorderstructure(propList, 'MultirateType','Response', ...
'InterpolationFactor', 'Specification', cpropList{1:fs_indx-1}, ...
'Fs','Fs_in','Fs_out',cpropList{fs_indx:end});
end
if propList.NormalizedFrequency
propList = rmfield(propList, {'Fs', 'Fs_in', 'Fs_out'});
end
propgrp = matlab.mixin.util.PropertyGroup(propList);
end
end
methods % public methods
varargout = butter(this,varargin)
varargout = ellip(this,varargin)
fs_in = get_fs_in(this,fs_in)
fs_out = get_fs_out(this,fs_out)
interpolationfactor = get_interpolationfactor(this,interpolationfactor)
cicconstructor = getcicconstructor(this)
defaultmethod = getdefaultmethod(this)
ratechangefactors = getratechangefactors(this)
varargout = ifir(this,varargin)
varargout = multistage(this,varargin)
g = nominalgain(this)
flag = passbandspecmet(Hf,Hd,ng)
interpolationfactor = set_interpolationfactor(this,interpolationfactor)
setratechangefactors(this,ratechangefactors)
varargout = thisdesign(this,method,varargin)
updatefdesignfactors(this)
vs = validstructures(this,varargin)
end % public methods
methods (Hidden) % possibly private or hidden
d = designopts(this,varargin)
varargout = iirlinphase(this,varargin)
validate_iir_designmethod(this,designMethod)
end % possibly private or hidden
methods (Static) % static methods
[specList] = getspeclist(response)
end % static methods
end % classdef