%---------------------------------------------------------------------%
%-------------------------FLL-----------------------------------------%
%---------------------------------------------------------------------%

clc;

????fs?=?16.368e6;				%[Hz]	采樣頻率
	fi?=?4.090e6;				%[Hz]	中頻頻率
????T?=?0.001;					%[s]	積分清除時(shí)間1ms
????n_accum?=?T?*?fs;			%?????	積分清除點(diǎn)數(shù)
????CNR?=?44;					%	??	載噪比44dB==-130dBmw
????SNR?=?CNR?-10*log10（fs）;	%	??	由載噪比得到信噪比
????addnoise?=?1;				%?1:?加噪聲;?0:?不加噪聲
????fd0?=?300;					%[Hz]?	多普勒初始頻率
????detfd?=?1000;				%[Hz/s]	多普勒變化率
????kf?=?2^32/fs;				%		頻率控制字轉(zhuǎn)換系數(shù)
????time?=?0.5;					%		仿真時(shí)間和仿真次數(shù)
????loopnum?=?fix（time/T）;		%		仿真點(diǎn)數(shù)/環(huán)路更新次數(shù)
????b_fll?=?0.9;				%[Hz]	鎖頻環(huán)帶寬
????wn?=?1.89?*?b_fll;			%		阻尼系數(shù)為0.707下中心頻率
????gain_nco?=?2*pi*fs/2^32;	%		NCO增益
????gain_disctim?=?1;			%		鑒相器增益
????K?=?gain_nco?*?gain_disctim;%		環(huán)路增益：NCO*鑒相器????

????k1?=?0.3;	%?修改自己的濾波系數(shù)
????k2?=?0.2;				%修改自己的濾波系數(shù)
	
	%?New?FLL-------------------------------------------------------------
	fllDampingRatio		=?0.7;		%?
	fllNoiseBandwidth	=?3;		%[Hz]
	fllCoherentT		=?0.001;	%?Coherent?Time
	%?FLL?parameter?calculation?accroding?to?settings-------
	[tau1Fll?tau2Fll]?=?calcLoopCoef（fllNoiseBandwidth?...
									fllDampingRatio?K）;
	oldFllNco???=?0.0;
	oldFllError?=?0.0;
	oldoldFllNco?=?0.0;

????endlasttime?=?0;
????
????fd_estimate?=?0;
????phaseadder?=?0;
????
????past_I_accum?=?0;
????past_Q_accum?=?0;
????
????freqoutdlf?=?0;
????past_past_freqoutdlf?=?0;
????past_freqoutdlf?=?0;
????past_freqerror?=?0;
	
	freq?=?zeros（1loopnum）;

for?index?=?1?:?loopnum

	????t?=?endlasttime?+?（1:n_accum）/fs;
????????????phase?=?2*pi*?[（fi+fd0）*t?+?1/2*detfd*t.^2];
%????????????phase?=?2*pi*（fi+fd）*（endlasttime?+?（1:n_accum）/fs）;
????????????endlasttime?=?endlasttime?+?T;
????????????freq（index）?=?fd0?+?detfd*endlasttime;
????????????cos_signal?=?cos（phase）;
????????if?addnoise?==?0
????????????cos_source?=?cos_signal;
????????e