www.pudn.com > GNSS_SDR.zip > checkPhase.m, change:2006-08-14,size:1911b


function word = checkPhase(word, D30Star) 
%Checks the parity of the supplied 30bit word. 
%The last parity bit of the previous word is used for the calculation. 
%A note on the procedure is supplied by the GPS standard positioning 
%service signal specification. 
% 
%word = checkPhase(word, D30Star) 
% 
%   Inputs: 
%       word        - an array with 30 bit long word from the navigation 
%                   message (a character array, must contain only '0' or 
%                   '1').  
%       D30Star     - the last bit of the previous word (char type). 
% 
%   Outputs: 
%       word        - word with corrected polarity of the data bits 
%                   (character array).  
 
%-------------------------------------------------------------------------- 
%                           SoftGNSS v3.0 
%  
% Written by Darius Plausinaitis and Dennis M. Akos 
%-------------------------------------------------------------------------- 
%This program is free software; you can redistribute it and/or 
%modify it under the terms of the GNU General Public License 
%as published by the Free Software Foundation; either version 2 
%of the License, or (at your option) any later version. 
% 
%This program is distributed in the hope that it will be useful, 
%but WITHOUT ANY WARRANTY; without even the implied warranty of 
%MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
%GNU General Public License for more details. 
% 
%You should have received a copy of the GNU General Public License 
%along with this program; if not, write to the Free Software 
%Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 
%USA. 
%-------------------------------------------------------------------------- 
 
% CVS record: 
% $Id: checkPhase.m,v 1.1.2.4 2006/08/14 11:38:22 dpl Exp $ 
 
if D30Star == '1' 
    % Data bits must be inverted 
    word(1:24) = invert(word(1:24)); 
end