[求助] matlab仿真实现三阶锁相环路跟踪高动态多普勒变化出现问题，急需指点[有源码] 已有1人参与

RT，最近在忙论文，但仿真出现问题，结果总是不对。用的模型是JPL的高动态模型，环路带宽根据跟踪门限设为90Hz，积分时间为1ms，但是好像就是一直没法锁相，鉴相误差一直较大，有没做过这方面的同学或前辈啊，急需指点和讨论！！ clc; clear all; Chip_rate = 6.3*10^6;          % 扩频码速率(chips/s) Spreadcode_len = 63;           % 扩频码长度(chips) Data_len = 240;                % 数据长度(symbols) Freq_carrier = 4*10^10;        % 射频载波频率(Hz) Freq_sample = 6.3*10^6;        % 接收机采样频率(Hz) Symbol_rate = 1*10^5;          % 符号速率(sym/s) SNR = -5;                     % 信噪比(dB) load GoldSequence.mat; PNcode = 2*GoldSequence(1ata_len,1:63)-1;       % 伪码长度：数据长度*63 n_chip = 63; g = 9.8;                       % 重力加速度(m/s^2) c = 3*10^8;                    % 光速(m/s) ts = 1/1890;                    % JPL的采样时间(s),所设置的值与扩码序列的长度有关 V0 = -500;                     % 初始速度(m/s) Theta0 = 2*pi*randn(1);        % 初始相位(rad) Time = [3 0.5 2 0.5 2];         Total_length = round(Time/ts); % Jerk = [zeros(1,3/ts) 100*g*ones(1,0.5/ts) zeros(1,2/ts) -100*g*ones(1,0.5/ts) zeros(1,2/ts)];    Jerk = [zeros(1,Total_length(1)) 100*g*ones(1,Total_length(2)) zeros(1,Total_length(3)) -100*g*ones(1,Total_length(4)) zeros(1,Total_length(5))];    Acceleration = [-25*g cumsum(Jerk(1:end-1)*ts)-25*g];                                             Velocity = [V0 cumsum(Acceleration(1:end-1)*ts + Jerk(1:end-1)*ts^2/2)+V0];                         Freq_Doppler = Freq_carrier / c * Velocity;                                                      Freq_Doppler_der1 = Freq_carrier / c * Acceleration;                                        Freq_Doppler_der2 = Freq_carrier / c * Jerk;                                                      Theta = Theta0 + 2*pi*cumsum(Freq_Doppler)*ts + 2*pi*cumsum(Freq_Doppler_der1).*ts^2/2 + 2*pi*cumsum(Freq_Doppler_der2).*ts^3/6; %================== 数据序列 ===================% Data_sequence = randi(2,1,160)-1;          %================== 信道编码 ===================% trellis = poly2trellis([5,4],[23 35 0;0 5 13]); Data_sequence_conv = convenc(Data_sequence,trellis);    %================== BPSK调制 ===================% Data_sequence_mod = BPSKMod(Data_sequence_conv);       %================== 扩频调制 ===================% Spread_sequence = Data_sequence_mod(1) * PNcode(1,; for i=2:1ata_len     Spread_sequence = cat(2,Spread_sequence,Data_sequence_mod(i) * PNcode(i,); end %================== 加频偏和噪声 ===================% Spread_sequence_offset = Spread_sequence .* exp(1i*Theta); Spread_sequence_noise = Noise_Generate(Spread_sequence_offset,SNR); PNcode1 = reshape(PNcode.',1,[]); Signal_despread = Spread_sequence_noise.*PNcode1;             w_nF_PLL = 90; T_IC = 1e-3; a3 = 1.1; b3 = 2.4; Simulation_len = length(Signal_despread); Signal_PLL = zeros(1,Simulation_len); NCO_Phase = zeros(1,Simulation_len); Discriminator_Out = zeros(1,Simulation_len); phase_third_derivate_temp = 0; phase_second_derivate1_temp = 0; for i=2:Simulation_len         Signal_PLL(i) = Signal_despread(i)*exp(-1i*mod(NCO_Phase(i-1),2*pi));     I_PLL(i) = real(Signal_PLL(i));     Q_PLL(i) = imag(Signal_PLL(i));     Discriminator_Out(i)=sign(I_PLL(i))*Q_PLL(i)/abs(Signal_PLL(i)); %     Discriminator_Out(i) = atan(Q_PLL(i)/I_PLL(i));         phase_third_derivate = T_IC*w_nF_PLL^3*Discriminator_Out(i);     phase_third_derivate1 = phase_third_derivate + phase_third_derivate_temp;     phase_third_derivate1_temp = phase_third_derivate1 + phase_third_derivate_temp;     phase_second_derivate = a3*w_nF_PLL^2*Discriminator_Out(i) + 1/2*phase_third_derivate1_temp;     phase_second_derivate1 = phase_second_derivate*T_IC + phase_second_derivate1_temp;     phase_second_derivate2 = phase_second_derivate1 + phase_second_derivate1_temp;     phase_derivate = 1/2*phase_second_derivate2 + b3*w_nF_PLL*Discriminator_Out(i);         NCO_Phase(i)=NCO_Phase(i-1) + T_IC*phase_derivate;         phase_third_derivate_temp = phase_third_derivate1;     phase_second_derivate1_temp = phase_second_derivate1;     end

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