function?ap?=?apeqp2（Napxwp）
%?APEQP2.M
%?MATLAB?m-file?for?ALLPASS?fractional?delay?design
%?using?EQUIRIPPLE?PHASE?approximation
%?format:?ap?=?apeqp2（Napxwp）
%?Input:?Nap?=?filter?order?N
%????????x?=?fractional?delay?（0?%????????wp?=?passband?edge?of?approximation?（0?%?Output:?Filter?coefficient?vector?ap?=?ap（1）...ap（N+1）
%?????????（Note?that?ap（1）=1?always）
%?Subroutines:?standard?MATLAB?&?SP?Toolbox?functions?&
%??????????????numint2.m?eigsolv2.m?envelop2.m
%?Timo?Laakso?27.02.1993
%?Revised?15.01.1996?by?Timo?Laakso
%?????????17.01.1996?by?Vesa?Valimaki

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%?Initialization:?
%
dw?=?wp/200;?????????%?201-point?approximation?grid
%dw?=?wp/511;?????????%?512-point?approximation?grid?（VPV?9.12.1996）
wf?=?[0:dw:wp];??????%?vector?of?freq.?pts
%
thP?=?-（Nap+x）*wf;??%?prescribed?phase
%
%?beta?and?initializations
%
beta?=?-0.5*x*wf;?beta2=2*beta;
sinB?=?sin（beta）;?cosB?=?cos（beta）;
wc?=?wf-wf;?WW?=?wc;?W0?=?wc+1-wc;?????%?weight?vectors
ap?=?zeros（1Nap+1）;?ap（1）=1;??????????%?allpass?coefficient?vector
P4?=?zeros（Nap+1）;?????????????????????%?eigenfilter?matrix
Nap1=Nap-1;
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%?Compute?P4:
%
EP?=?2;?????%?initial?exponent?parameter?????
%?initial?value?ap?from?P1!
lser=1000;?it=0;
%while?（（lser>1.0E-8）&（it<51））;
while?（（lser>1.0E-12）&（it<171））;??%?VPV?9.12.1996
??if?（EP<51）
????if?（lser<1.0E-4）
??????if?（EP<4）?EP?=?EP+1;
??????elseif?（EP<10）?EP?=?EP+2;
??????else?EP?=?EP+5;
??????end;??????%?3rd?if
??????lser?=?1000;
????end?????????%?2nd?if
??end???????????%?1st?if
??it?=?it+1;??%?iteration?number?
??Hap?=?freqz（ap1wf）;???%?weight?function?from?the?previous?solution
??wc?=?cosB.*real（Hap）?-?sinB.*imag（Hap）;
??thAP4?=?-Nap*wf+2*unwrap（angle（freqz（1apwf）））;
??deltaT4?=?thP-thAP4;
??wenv?=?envelop2（deltaT4）;?%?create?the?envelope?for?equiripple?weighting
??W?=?（wenv.^EP）./（wc.^2）;
??for?k=1:Nap+1
????k1wf?=?（k-1）*wf;
????cT（k）?=?numint2（W.*cos（k1wf））;?
????cH（k）?=?numint2（W.*cos（beta2-k1wf））;
????rH（k）?=?numint2（W.*cos（beta2-（k+Nap1）*wf））;
??end?%?for?k
??T1?=?toeplitz（cT）;?H1?=?hankel（cHrH）;
??P4?=?T1-H1;?apold?=?ap;
??ap=?eigsolv2（P4Nap+1）;?????%?solve?the?eigenvalue?problem
??ap?=?（ap+（EP-1）*apold）/EP;
??dif=apold-ap;?lser=dif*dif‘;
end??????????????%?while?lserit
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

?屬性????????????大小?????日期????時(shí)間???名稱
-----------?---------??----------?-----??----
?????文件????????2496??1996-12-09?10:21??apeqp2.m
?????文件????????2563??1996-12-12?16:11??apeqpd2.m
?????文件????????2525??1996-02-01?12:58??apfar2.m
?????文件?????????692??1996-02-01?12:58??apflat2.m
?????文件????????1483??1996-02-01?12:58??aplsp2.m
?????文件????????1540??1996-02-01?12:58??aplspd2.m
?????文件????????1855??1996-02-01?12:58??aplspdi2.m
?????文件????????1742??1996-02-01?12:58??aplspi2.m
?????文件?????????323??1996-02-01?12:58??bincof2.m
?????文件?????????288??1996-02-01?12:58??eigsolv2.m
?????文件?????????767??1996-02-01?12:58??envelop2.m
?????文件????????7693??1996-02-01?12:58??fdap2.m
?????文件???????12337??1996-02-01?12:58??fdfir2.m
?????文件????????2458??1996-02-01?12:58??firfar2.m
?????文件?????????679??1996-02-01?12:58??hcontro2.m
?????文件?????????758??1996-02-01?12:58??heqrip2.m
?????文件????????1045??1996-02-01?12:58??hgls2.m
?????文件?????????869??1996-02-01?12:58??hlagr2.m
?????文件?????????957??1996-02-01?12:58??hsincw2.m
?????文件?????????971??1996-02-01?12:58??hsplin2.m
?????文件????????1747??1996-02-01?12:58??iniheq2.m
?????文件?????????957??1996-02-01?12:58??inihip2.m
?????文件????????1152??1996-02-01?12:58??inihsin2.m
?????文件?????????440??1996-02-01?12:58??numint2.m