function data_enc = space(data,dlt,slt,varargin)%SPACE Space-time channel encoder%   Q = SPACE(D,DLT,SLT) performs the data (D) encoding based on the DLT%   and SLT look-up tables. The tables for AT&T space-time codes these%   tables may be easily obtained from the LTABLE function. In fact the%   structure of look-up tables is as general as possible. By the way%   the encoder doesn't care about the content of the look-up tables. %   This feature allows you to force the encoder's operation mode into %   the arbitrary scheme. Even an encoding based on block codes may be%   performed using the space function. This is when the slt table is%   filled with equal entries. There is also a zero-force check performed%   during each frame encoding process. %%   Q = SPACE(D,DLT,SLT,'PropertyName',PropertyValue,...)%%   Space Property List%%   Display       {'off'} | 'report'%   Echo           'on' | {'off'}%%   See also LTABLE, DISPDES.%   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 ECHOname = 'SPACE';[idt,tag] = iecho(name);nopts = length(varargin) / 2;opts = reshape(varargin,[2 nopts])';ord1 = strmatch('Echo',opts(:,1));ord2 = strmatch('Display',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% Displayif isempty(ord2) % there's no such option	report = 'off'; % default valueelse % there's relevant option	report = opts{ord2,2};end%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% BODY BEGIN %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%[fr_length,l,frames] = size(data);[foo1,md,foo2] = size(dlt);s = 1; % setting up initial statefor k = 1:frames	for i = 1:fr_length                           % stc encoder 		d = data(i,1,k) + 1; % data_dim=1           % stc encoder                          data_enc(i,:,k) = dlt(s,d,:);               % stc encoder    s = slt(s,d,:);                             % stc encoder  end                                           % stc encoder  % zero force flag  if (i == fr_length) & (s ~= 1)     zf_check(k,1) = 0;  else    zf_check(k,1) = 1;  endend%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% BODY END %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%if ech 	disp(' ');	if zf_check == 1        disp([tag,'All frames were encoded successfuly.']);	else        disp([tag,'Some frames were encoded uncorrectly!']);        disp([idt,'Use |FullReport| option to get more details.']);	end		switch report	case 'off'		disp(' ');		return	case 'report'		[m,n] = size(zf_check);		table(:,1) = [1:m]';		table(:,2) = zf_check;		str1 = sprintf([idt,' #%3d  | %3d\n'],table');				disp(' ');		disp([idt,' Frame | Status']);		disp([idt,'-------+-------']);		disp(str1);		disp([idt,'Legend: "1" = OK; "0" = wrong encoded.']);	end	disp(' ');end