path: root/Satellite_Communication/chapter_6.ipynb

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 },
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 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "chapter 6: Multiple Access Techniques"
     ]
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Example 6.1, page no-230"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "'''length of reference and traffic burst'''\n",
      "#Variable Declaration\n",
      "t=20       #TDMA frame length in ms\n",
      "lc=352     #length of carrier and clock recovery frequency in bits\n",
      "lu1=48     #length of unique word in bits\n",
      "lo=510     #length of order wire channel in bits\n",
      "lm= 256    #length of management channel in bits\n",
      "lt=320     # length of transmit timming channel in bits\n",
      "ls1=24     # length of service channel in bits\n",
      "gt=64      # Guard time in bits\n",
      "rb=2       # reference burst\n",
      "\n",
      "\n",
      "#Calculation\n",
      "lr=lc+lu1+lo+lm+lt\n",
      "tb=lc+lu1+lo+ls1\n",
      "tob=(lr*rb)+(tb*t)+((t+rb)*gt)\n",
      "\n",
      "#Result\n",
      "print(\"(a)\\nThe length of reference burst(from given data) is %d bits\\n\\n(b)\\nThe length of traffic burst premable(from given data)is %d bits\\n\\n(c)\\nTotal number of overhead bits is %d bits\"%(lr,tb,tob))\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "(a)\n",
        "The length of reference burst(from given data) is 1486 bits\n",
        "\n",
        "(b)\n",
        "The length of traffic burst premable(from given data)is 934 bits\n",
        "\n",
        "(c)\n",
        "Total number of overhead bits is 23060 bits\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Example 6.2, page no-230"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "'''Frame efficiency'''\n",
      "import math\n",
      "#Variable Declaration\n",
      "t=20          # TDMA frame length in ms\n",
      "lc=352        # length of carrier and clock recovery frequency in bits\n",
      "lu1=48        # length of unique word in bits\n",
      "lo=510        # length of order wire channel in bits\n",
      "lm=256        # length of management channel in bits\n",
      "lt=320        # length of transmit timming channel in bits\n",
      "ls1=24        # length of service channel in bits\n",
      "gt=64         # Guard time in bits\n",
      "rb=2          # reference burst\n",
      "br=90.0*10**6 # burst bit rate 90Mbps\n",
      "\n",
      "\n",
      "#Calculation\n",
      "bfr=br*t*10**-3\n",
      "lr=lc+lu1+lo+lm+lt\n",
      "tb=lc+lu1+lo+ls1\n",
      "tob=(lr*rb)+(tb*t)+((t+rb)*gt)\n",
      "feff=(bfr-tob)*100/bfr\n",
      "feff=math.ceil(feff*100)/100\n",
      "\n",
      "#Result\n",
      "print(\"Frame efficiency = %.2f%%\"%feff)\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Frame efficiency = 98.72%\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Example 6.3, page no-231"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "'''Maximum no of PCM voice channels'''\n",
      "import math\n",
      "#Variable Declaration\n",
      "t=20            # TDMA frame length in ms\n",
      "lc=352          # length of carrier and clock recovery frequency in bits\n",
      "lu1=48          # length of unique word in bits\n",
      "lo=510          # length of order wire channel in bits\n",
      "lm= 256         # length of management channel in bits\n",
      "lt=320          # length of transmit timming channel in bits\n",
      "ls1=24          # length of service channel in bits\n",
      "gt=64           # Guard time in bits\n",
      "rb=2            # reference burst\n",
      "br=90.0*10**6   # burst bit rate 90Mbps\n",
      "dr= 64.0*10**3  #data rate 64 kbps\n",
      "\n",
      "\n",
      "#Calculation\n",
      "bfr=br*t*10**-3\n",
      "lr=lc+lu1+lo+lm+lt\n",
      "tb=lc+lu1+lo+ls1\n",
      "tob=(lr*rb)+(tb*t)+((t+rb)*gt)\n",
      "feff=(bfr-tob)*100/bfr\n",
      "feff=math.ceil(feff*100)/100\n",
      "vsb=dr*t*10**-3\n",
      "x=bfr*feff/100\n",
      "\n",
      "#Result\n",
      "print(\"The number of bits in a frame for a voice sub-burst is %d\\n\\nThe total no of bits available in a frame for carrying traffic is %d\\n\\nMaximum no of PCM voice channels in a frame is %d channels\"%(vsb,x,x/vsb))\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "The number of bits in a frame for a voice sub-burst is 1280\n",
        "\n",
        "The total no of bits available in a frame for carrying traffic is 1776960\n",
        "\n",
        "Maximum no of PCM voice channels in a frame is 1388 channels\n"
       ]
      }
     ],
     "prompt_number": 4
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Example 6.4, page no-231"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "'''Doppler Shift'''\n",
      "import math\n",
      "#Variable Declaration\n",
      "R=42150.0       # orbital radius of satellite\n",
      "oi=0.25/100.0   # orbit inclination\n",
      "acc=0.3         # error of 0.3 degree\n",
      "c=3.0*10**8     # speed of light\n",
      "x=oi*R\n",
      "\n",
      "\n",
      "#Calculation\n",
      "x=math.ceil(x*10)/10\n",
      "y=R*2*math.pi*acc/360.0\n",
      "y=math.ceil(y*10)/10\n",
      "z=math.sqrt(x**2+y**2)\n",
      "z=math.ceil(z*10)/10\n",
      "delay=z*10**6/c\n",
      "delay=math.floor(delay*1000)/1000\n",
      "pd=2*delay\n",
      "\n",
      "\n",
      "#Result\n",
      "print(\"variation in altitude caused by orbit inclination = %.1fkm\\n variation due to station-keeping error of 0.3\u00b0 = %.1fkm\"%(x,y))\n",
      "print(\"\\n Both these errors will introduce a maximum range variation of %.1fkm\\n This cause a one-way propagation delay of %.3fms\\n Round trip propagation delay =%.2fms\\n Dopler Shift = %.2f ms in 8h=56.25 ns/s\"%(z,delay,delay*2,pd))\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "variation in altitude caused by orbit inclination = 105.4km\n",
        " variation due to station-keeping error of 0.3\u00b0 = 220.7km\n",
        "\n",
        " Both these errors will introduce a maximum range variation of 244.6km\n",
        " This cause a one-way propagation delay of 0.815ms\n",
        " Round trip propagation delay =1.63ms\n",
        " Dopler Shift = 1.63 ms in 8h=56.25 ns/s\n"
       ]
      }
     ],
     "prompt_number": 5
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Example 6.5, page no-238"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "'''Chip Duration and maximum chip rate'''\n",
      "#Variable Declaration\n",
      "de=40.0          # Doppler effect variation due to station-keeping errors in ns/s\n",
      "d=280.0          # Sttelite round trip delay in ms\n",
      "c=20.0/100.0     # DS-CDMA signals should not exceed 20% of the chip duration\n",
      "\n",
      "#Calculation\n",
      "te=de*10**-9*d*10**-3\n",
      "tc=te/c\n",
      "\n",
      "\n",
      "#Result\n",
      "print(\"Chip Duration, Tc = %.0f ns \\n This gives maximum chip rate as (1/56)Gbps = 1000/56 Mbps = %.3f Mbps\"%(tc*10**9,1000.0/56.0))\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Chip Duration, Tc = 56 ns \n",
        " This gives maximum chip rate as (1/56)Gbps = 1000/56 Mbps = 17.857 Mbps\n"
       ]
      }
     ],
     "prompt_number": 6
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Example 6.6, page no-238"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "'''maximum permissible Dopler effect variation'''\n",
      "#Variable Declaration \n",
      "cr=25.0             #Chip rate is 25 Mbps\n",
      "c=20.0/100.0        # DS-CDMA signals should not exceed 20% of the chip duration\n",
      "d=1000/cr           #chip duration in ns\n",
      "\n",
      "\n",
      "#Calculation\n",
      "tr=c*d\n",
      "x=tr/(280.0*10**-3)\n",
      "\n",
      "#Result\n",
      "print(\"The maximum allowable timing error per satellite round trip is %.0f ns\\n This %.0f ns error is to occur in 280 ms.\\n Therefore, maximum permissible Dopler effect variation is %.2f ns/s\"%(tr,tr,x))\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "The maximum allowable timing error per satellite round trip is 8 ns\n",
        " This 8 ns error is to occur in 280 ms.\n",
        " Therefore, maximum permissible Dopler effect variation is 28.57 ns/s\n"
       ]
      }
     ],
     "prompt_number": 7
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Example 6.7, page no-238"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "'''Processing gain'''\n",
      "import math\n",
      "#Variable Declaration\n",
      "cr=20.0*10**6           #chip rate in Mbps\n",
      "ir= 20.0*10**3          #information bit rate\n",
      "\n",
      "\n",
      "#Calculation\n",
      "g=10*math.log10((cr)/(ir))\n",
      "\n",
      "#Result\n",
      "print(\"Noise reduction achhievable = Processing gain = %.0f dB\"%g)\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Noise reduction achhievable = Processing gain = 30 dB\n"
       ]
      }
     ],
     "prompt_number": 8
    }
   ],
   "metadata": {}
  }
 ]
}