% steplfm - stepped train of LFM pulses% creates stepped-LFM signal for use with ambiguity function plotting% programs tpdf=input(' T*Df (typ. = 0 or 5) = ? ');tpb=input(' T*B (typ. = 0 or 12.5) = ? ');trovertp=input('Tr/T (typ. = 4) (Using 1 implies contiguous pulses) = ? ');nn=input(' Number of pulses (integer, typ. = 3, 4, 8 or 16) = ? ');mm=50;mm2=mm/2-1;ufm=ones(1,mm);ddf=tpb/mm^2;ffm=ddf*(-mm2:mm2+1)-ddf/2;mtr=(trovertp-1)*mm;space1=zeros(1,mtr);u_step1=[ufm space1];f_step1=[ffm space1];f1=-(nn-1)/2;u_step=u_step1;f_step=f_step1;f_add=[f1*u_step1];reverse=input(' Alternating slopes (yes=1, no=0) = ? ');if reverse==1    rv=-1;else    rv=1;endcost=input('Linear (=0) or Costas (=1) steps = ? ');if cost ==1;    if nn==16        qq=[6 14 2 3 10 8 11 15 9 1 13 12 5 7 4] ;    elseif nn==8            qq=[7 2 5 1 6 4 3];    elseif nn==4                qq=[2 3 1];    elseif nn==3                qq=[2 1];    endendif cost==0  % linear steps      qq=[1:nn-1];endfor q= qq            u_step=[u_step u_step1];            f_step=[f_step (rv)^q*f_step1];            f_add=[f_add  (f1+q)*u_step1];endf_total=f_step+(tpdf/mm)*f_add;disp('')disp('  In ambfn1  ')disp('    use  "u_step" as Signal elements  and   "f_total" as Frequency coding')disp(' ')disp('  In ambfn7  ')disp('     use    "u_amp = u_step;"     and     "f_basic = f_total;" ')disp(' ')