各图符参数设置如下表所示：

编号 库/名称 21 Comm: PN Gen 参数 Reg Len = 5，Taps = [2- 5]，Seed = -1， Threshold = 0，True = 1，False = -1， Max Rate = 560e+3 Hz 22 Source: Pulse Train 23 Logic: Buffer Amp = 1 v，Freq = 14e+3 Hz， PulseW=35.7143e-6 sec，Offset = -500e-3 v Phase = 0 deg，Max Rate = 560e+3 Hz Gate Delay = 0 sec，Threshold = 500e-3 v True Output = 1 v，False Output = -1 v， Rise Time = 0 sec，Fall Time = 0 sec， Max Rate = 560e+3 Hz 2 15 Multiplier: Non Parametric Source: Sinusoid Inputs from t23p0 t15p0，Outputs to 4 17 Max Rate = 560e+3 Hz Amp = 1 v，Freq = 56e+3 Hz，Phase = 0 deg Output 0 = Sine t2 ，Output 1 = Cosine Max Rate (Port 0) = 560e+3 Hz 3 Operator: Linear Sys Butterworth Bandpass IIR 6 18 Multiplier: Non Parametric Source: Sinusoid 3 Poles，Low Fc = 42e+3 Hz， Hi Fc =70e+3 Hz，Quant Bits = None ， Init Cndtn = Transient，DSP Mode Disabled， Max Rate = 560e+3 Hz Inputs from t18p0 t3p0 ，Outputs to 8， Max Rate = 560e+3 Hz Amp = 1 v，Freq = 56e+3 Hz，Phase = 0 deg Output 0 = Sine t6 ，Output 1 = Cosine ， Max Rate (Port 0) = 560e+3 Hz 8 Operator: Linear Sys IIR 10

3 Poles，Fc = 14e+3 Hz，Quant Bits = None， Disabled， Max Rate = 560e+3 Hz， Non-Interpolating，Delay = 0 sec= 0.0 Butterworth Lowpass Init Cndtn = Transient， DSP Mode Operator: Delay

smp， Output 0 = Delay t9 ，Output 1 = Delay - dT Max Rate (Port 0) = 560e+3 Hz 9 Operator: Sampler Interpolating，Rate = 560e+3 Hz， Aperture = 0 sec，Aperture Jitter = 0 sec， Max Rate = 560e+3 Hz 11 Operator: Hold Last Value, Gain = 1, Out Rate = 560e+3 Hz, Max Rate = 560e+3 Hz 12 Logic: Buffer Gate Delay = 0 sec,Threshold = 0 v, True Output = 1 v,False Output = 0 v, Rise Time = 0 sec,Fall Time = 0 sec, Max Rate = 560e+3 Hz 2、PCM编码和解码系统仿真

各图符参数设置如下表所示： 编号 73 库/名称 参数 Output 0 = Sine t3，Output 1 = Cosine ， Max Rate(Port 0) = 560e+3 Hz 72

Source: Sinusoid Amp = 2 v，Freq = 600 Hz， Phase = 0 deg，Source: Sinusoid Amp = 2 v，Freq = 400 Hz，Phase = 0 deg，

Output 0 = Sine t3， Output 1 = Cosine， Max Rate (Port 0) = 560e+3 Hz 71 Source: Sinusoid Amp = 2 v，Freq = 200 Hz，Phase = 0 deg，Output 0 = Sine t3 ，Output 1 = Cosine ，Max Rate (Port 0) = 560e+3 Hz 3 6 8 Adder:NonParametric Logic: ADC Inputs from t71p0 t72p0 t73p0， Outputs to 4 6，Max Rate = 560e+3 Hz Two's Complement Gate Delay = 0 sec，Threshold = 500e-3 v，True Output = 1 v，False Output = 0 v，No. Bits = 8，Min Input = -5 v，Max Input = 5 v，Rise Time = 0 sec，Analog = t6 Output 0，Clock = t14 ，Output 0 14 Source:PulseTrain 40 41 MetaSystem:Untitled1 Comm: TD Mux No. Inputs = 8，Time per Input = 571.429e-6 sec，Time Slot 0 = t32 Output 0，Time Slot 1 = t33 Output 0，Time Slot 2 = t34 Output 0，Time Slot 3 = t35 Output 0，Time Slot 4 = t36 Output 0，Time Slot 5 = t37 Output 0，Time Slot 6 = t38 Output 0，Time Slot 7 = t39 Output 0，Max Rate = 560e+3 Hz 43 46 74 Operator: Hold MetaSystem:Untitled2 Operator: Delay Last Value Gain = 1，Out Rate = 560e+3 Hz，Max Rate = 560e+3 Hz C:\\Users\\Administrator\\Desktop ...\\Untitled1.mta Auto-Linked Non-Interpolating Delay = 521.429e-6 sec= 292.0 smp，Output 0 = Delay t45，Output 1 = Delay - dT，Max Rate (Port 0) = 560e+3 Hz 45 Comm: TD DeMux No. Outputs = 8，Time per Output = 571.429e-6 sec，Output 0 = Time Slot 0 t9，Output 1 = Time Slot 1 t9，Output 2 = Time Slot 2 Amp = 2 v，Freq = 1.75e+3 Hz，PulseW = 285.714e-6 sec，Offset = -1 v，Phase = 0 deg，Max Rate = 560e+3 Hz Not Auto-Linked Comm: Compander A-Law Max Input = ±5，Max Rate = 560e+3 Hz

t9，Output 3 = Time Slot 3 t9，Output 4 = Time Slot 4 t9，Output 5 = Time Slot 5 t9，Output 6 = Time Slot 6 t9，Output 7 = Time Slot 7 t9 ，Max Rate (Port 0) = 70e+3 Hz 9 Logic: DAC Two's Complement Gate Delay = 0 sec，Threshold = 500e-3 v，No. Bits = 8，Min Output = -5 v，Max Output = 5 v，D-0 = t45 Output 0，D-1 = t45 Output 1，D-2 = t45 Output 2，D-3 = t45 Output 3，D-4 = t45 Output 4 7 12 Comm: DeCompand A-Law Max Input = ±5，Max Rate = 70e+3 Hz Operator:Linear Sys Butterworth Lowpass IIR 3 Poles，Fc = 600 Hz，Quant Bits = None，Init Cndtn = Transient，DSP Mode Disabled，Max Rate = 70e+3 Hz 四、仿真结果及对应的结果数据分析 1、各点时域波形

（1）输入m序列波形

系统产生一串伪随机序列，并将其设置为双极性不归零波形，如上图所示。