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+{
+"cells": [
+ {
+		   "cell_type": "markdown",
+	   "metadata": {},
+	   "source": [
+       "# Chapter 5: Pulse Modulation"
+	   ]
+	},
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 1.A: Sample_and_Hold.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"clear;\n",
+"clc;\n",
+"//('current through the capacitor is i=C(dv/dt)');\n",
+"\n",
+"t=15; //acquisition time in us\n",
+"i=5; //current in mA\n",
+"v=5; //maximum voltage across capacitor in V\n",
+"\n",
+"\n",
+"// to satisfy current requirement\n",
+"disp('to satisfy current requirement');\n",
+"C_current_req=i*t/v;\n",
+"disp(C_current_req,'C(nF)=');\n",
+"\n",
+"//to satisfy accuracy requirement\n",
+"disp('to satisfy accuracy requirement');\n",
+"\n",
+"C_accuracy_req=t/(6.9*15)*1000;// to convert into 'nanoFarad'\n",
+"\n",
+"disp(C_accuracy_req,'C(nF)=');\n",
+"\n",
+"disp('to satisfy both requirements,smaller of the two can b taken');\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.1: Sampling.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"clear;\n",
+"clc;\n",
+"disp('for 8-KHz sampling,the frequencies present are...(in KHz)');\n",
+"\n",
+"Fs=8; //sampling frequency\n",
+"Fst=3.5 //single tone frequency\n",
+"\n",
+"disp(Fst);\n",
+"disp(-Fst);\n",
+"disp(Fs-Fst);\n",
+"disp(-(2*Fs+Fst),(2*Fs+Fst),-(Fs+Fst),(Fs+Fst),(Fs-Fst));\n",
+"disp('...etc...');\n",
+"\n",
+"disp('in this case, if the LPF is designed with cut-off frequency(8/2= 4-KHz)');\n",
+"disp('then the maximum passable frequency is 3.5-KHz');\n",
+"disp('for 5-KHz sampling,the frequencies present are...(in KHz)');\n",
+"\n",
+"Fs=5;//new sampling frequency\n",
+"disp(Fst);\n",
+"disp(-Fst);\n",
+"disp(Fs-Fst);\n",
+"disp(-(2*Fs+Fst),(2*Fs+Fst),-(Fs+Fst),(Fs+Fst),(Fs-Fst));\n",
+"disp('...etc...');\n",
+"\n",
+"disp('in this case, if the LPF is designed with cut-off frequency(5/2=2.5-KHz)');\n",
+"disp('then the original signal cant be passed');\n",
+"disp('therefore, the signal cant be reconstructed');\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.2_A: Aliasing_Frequency.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"clc;\n",
+"clear;\n",
+"F_audio=5; //Audio input Frequency in kHz\n",
+"\n",
+"F_sampling=2*F_audio;\n",
+"\n",
+"disp(F_sampling,'The Minimum Sampling Frequency (in kHz)');\n",
+"\n",
+"disp('When the audio Frequency of 6 Khz enters the Sample and Hold circuit');\n",
+"disp('it will overlap the audio spectrum, and the alaising frequency is 4 kHz');"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.2: Sampling_Rate.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"clc;\n",
+"clear;\n",
+"\n",
+"//x(t)=2sin(4000*pi*t)+3sin(5000*pi*t)+4sin(8000*pi*t)\n",
+"\n",
+"fh=8000/2;\n",
+"fl=4000/2;\n",
+"\n",
+"disp(fh,'a) Highest Frequency component(in Hz)');\n",
+"disp(fl,'Lowest Frequency component(in Hz)');\n",
+"\n",
+"fs=2*fh;\n",
+"disp(fs,' Minimum Sampling frequency(in Hz)');\n",
+"\n",
+"Bw=fh-fl;\n",
+"disp(Bw,' b)Bandwidth(in Hz) is');\n",
+"\n",
+"n=fh/Bw;\n",
+"disp(n,'integer factor');\n",
+"\n",
+"Fs_new=2*fh/n;\n",
+"disp(Fs_new,'Required Sampling frequency in this case(in Hz) is');\n",
+"\n",
+""
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.3_A: PCM_system.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"clc;\n",
+"clear;\n",
+"fm=5;// maximum analog frequency in kHz\n",
+"Min_dyna_range=35;\n",
+"Vr=3; //Voltage in the receiver in V\n",
+"\n",
+"//a)\n",
+"F_sampling=2*fm;\n",
+"\n",
+"//b)\n",
+"n=Min_dyna_range/6;\n",
+"k=(Vr-(-Vr)+1);// inclusive of sign bit\n",
+"\n",
+"//c)\n",
+"Resolution=Vr/(2^(7));\n",
+"\n",
+"//d)\n",
+"Max_quant_Error=Resolution/2\n",
+"\n",
+"disp(F_sampling,'a)Minimum Sampling Rate(in kHz) =');\n",
+"disp(n,'b) Minimum dynamic Range is');\n",
+"disp(' But Closest whole number is 6. Henc,6 bits must be used for amplitude' );\n",
+"disp('But the amplitude range is from -3 to +3 V,hence a sign bit also   ');\n",
+"disp( k,'becomes necessary..Therefore,the total number of bits');\n",
+"disp(Resolution,'c) Resolution(in V) =');\n",
+"disp(Max_quant_Error,' d)MAximum Quantization Error (in V) ');"
+   ]
+   }
+,
+{
+		   "cell_type": "markdown",
+		   "metadata": {},
+		   "source": [
+			"## Example 5.4_A: Bandwidth_of_PCM_system.sce"
+		   ]
+		  },
+  {
+"cell_type": "code",
+	   "execution_count": null,
+	   "metadata": {
+	    "collapsed": true
+	   },
+	   "outputs": [],
+"source": [
+"clc;\n",
+"clear;\n",
+"n=16;// Number of telephone lines\n",
+"m=256;//Quantization levels\n",
+"q=8;// since 2^(q)=256\n",
+"\n",
+"fs=10;//Sampling frequency in kHz\n",
+"\n",
+"Bw=[(16*9)+1]*10*10^(3);\n",
+"\n",
+"disp(Bw,'Bandwidth (in Hz ) is');"
+   ]
+   }
+],
+"metadata": {
+		  "kernelspec": {
+		   "display_name": "Scilab",
+		   "language": "scilab",
+		   "name": "scilab"
+		  },
+		  "language_info": {
+		   "file_extension": ".sce",
+		   "help_links": [
+			{
+			 "text": "MetaKernel Magics",
+			 "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
+			}
+		   ],
+		   "mimetype": "text/x-octave",
+		   "name": "scilab",
+		   "version": "0.7.1"
+		  }
+		 },
+		 "nbformat": 4,
+		 "nbformat_minor": 0
+}