www.gusucode.com > UWB_matlab源码程序 > CP0803/cp0803_PPMcorrmask_R.m
% % FUNCTION 8.12 : "cp0803_PPMcorrmask_R" % % Evaluates the correlation mask ('mask') for a RAKE % receiver in the case of binary PPM UWB signals. % 'ref' is the reference signal (with no modulation) % which is produced by the 2PPM+TH transmitter % 'fc' is the sampling frequency in Hertz % 'numpulses' is the number of transmitted pulses % 'dPPM' is the value of the PPM shift in seconds % 'rake' represents the estimated discrete-type impulse % response % % Programmed by Guerino Giancola % function [mask] = ... cp0803_PPMcorrmask_R(ref,fc,numpulses,dPPM,rake) % --------------------------------------------- % Step One - Evaluation of the correlation mask % --------------------------------------------- dt = 1 / fc; LR = length(ref); % Energy normalization Epulse = (sum((ref.^2).*dt))/numpulses; nref = ref./sqrt(Epulse); % Rake convolution mref = conv(nref,rake); mref = mref(1:LR); % Mask construction PPMsamples = floor (dPPM ./ dt); sref(1:PPMsamples)=mref(LR-PPMsamples+1:LR); sref(PPMsamples+1:LR)=mref(1:LR-PPMsamples); mask = mref-sref;