function sig_down = mfilter(sig,varargin)%MFILTER Matched filter%   Y = MFILTER(X) passes the incoming signal X along the matched filter%   and resamples filtered signal once per a symbol period.%%   Y = MFILTER(X,'PropertyName',PropertyValue,...)% %   Detect Property List% %   SymbolSamples  value%   SamplePeriod   value%   Gain           value%   Pulse          value%   Echo           'on' | {'off'}%%   See also DETECT.%   Copyright 2001-2003 Kamil Anis, anisk@feld.cvut.cz%   Dept. of Radioelectronics, %   Faculty of Electrical Engineering%   Czech Technical University in Prague%   $Revision: 2.1 $  $Date: 2003/1/16 17:33:28 $%   --%   <additional stuff goes here>global ECHO PULSE GAIN SYMB_SAMPLES SMPLPERname = 'MFILTER';[idt,tag] = iecho(name);nopts = length(varargin) / 2;opts = reshape(varargin,[2 nopts])';ord1 = strmatch('Echo',opts(:,1));ord2 = strmatch('SymbolSamples',opts(:,1));ord3 = strmatch('SamplePeriod',opts(:,1));ord4 = strmatch('Gain',opts(:,1));ord5 = strmatch('Pulse',opts(:,1));% Echoif ~isempty(ord1) % first check whether local option exists	value1 = opts{ord1,2};	switch value1	case 'on'		ech = 1;	case 'off'		ech = 0;	otherwise		disp(' ');		disp([tag,'Invalid option for Echo property.']);		disp([idt,'Possible values are ''on''|{''off''}.']);		disp(' ');		ech = 0;	endelse	if ~isempty(ECHO) % than check whether global option exists		switch ECHO		case 'on'			ech = 1;		case 'off'			ech = 0;		otherwise			disp(' ');			disp([tag,'Invalid option for Echo property.']);			disp([idt,'Possible values are ''on''|{''off''}.']);			disp(' ');			ech = 0;		end	else % if there are no settings use the defaults		ech = 0; % default value	endend% SymbolSamplesif ~isempty(ord2) % first check whether local option exists	samples = opts{ord2,2};else	if ~isempty(SYMB_SAMPLES) % than check whether global option exists		samples = SYMB_SAMPLES;	else % if there are no settings use the defaults		samples = 4; % default value	endend% SamplePeriodif ~isempty(ord3) % first check whether local option exists	smplper = opts{ord3,2};else	if ~isempty(SMPLPER) % than check whether global option exists		smplper = SMPLPER;	else % if there are no settings use the defaults		smplper = 1; % default value	endend% Gainif ~isempty(ord4) % first check whether local option exists	gain = opts{ord4,2};else	if ~isempty(GAIN) % than check whether global option exists		gain = GAIN;	else % if there are no settings use the defaults		gain = 1; % default value	endend% Pulseif ~isempty(ord5) % first check whether local option exists	pulse = opts{ord5,2};else	if ~isempty(PULSE) % than check whether global option exists		pulse = PULSE;	else % if there are no settings use the defaults		pulse = 1; % default value	endend%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% BODY BEGIN %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%[sig_length,space_dim,frames] = size(sig);for k = 1:frames	% passing the signal through matched filter  clear sig_mf;	for j = 1:space_dim    sig_mf(:,j) = smplper * conv(pulse,sig(:,j,k)) / gain;	end  % omiting the sig begining to prevent of insecure decisions	delay = length(pulse);	sig_mf = sig_mf(delay:end-delay,:,:);	% sampling at symbol period (Ns in Dt)	sig_down(:,:,k) = downsample(sig_mf,samples);end%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% BODY END %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%if ech [down_length,frames] = size(sig_down);	str1 = num2str(down_length);	str2 = num2str(frames);		disp(' ');	disp([tag,'Total length -> ',str1,' samples; ',str2,' frame(s).']);	disp(' ');end