{ "metadata": { "name": "", "signature": "sha256:15f18d4eac7b181ba51c6696eba06fa436baa89f07a517b2b2096748a0e3b407" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 13: Interference" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 13.1, Page 350" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable Declaration\n", "EIRP1=34 #desired carrier EIRP from satellite(dB)\n", "G1=44 # ground station receiving antenna gain(dB)\n", "G2=24.47 #Gain in desired direction(dB)\n", "EIRP2=34 #EIRP by interfering satellite(dB)\n", "PD=4 #Polarization discrimination(dB)\n", "\n", "#Calculation\n", "\n", "CIR=EIRP1-EIRP2+G1-G2+PD #Carrier to Interference ratio(dB)\n", "\n", "#Result\n", "\n", "print \"The Carrier to interfernce ratio at the ground receiving antenna is\",CIR,\"dB\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The Carrier to interfernce ratio at the ground receiving antenna is 23.53 dB\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 13.2, Page 350" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable Decalration\n", "\n", "PA=24 #Transmit power by station A(dBW)\n", "G1=54 #Antenna Gain(dB)\n", "PC=30 #Transmit power by station C(dBW)\n", "G2=24.47#off-axis gain in the S1 direction(dB)\n", "PD=4 #Polarization discrimination(dB)\n", "\n", "#Calculation\n", "\n", "CIR=PA-PC+G1-G2+PD #Carrier to Interference ratio(dB)\n", "\n", "#Result\n", "\n", "print \"The Carrier to interfernce ratio on uplink is\",CIR,\"dB\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The Carrier to interfernce ratio on uplink is 27.53 dB\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 13.3, Page 351" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#Variable Declaration\n", "\n", "CIR1=27.53 #Carrier to interference ratio from Example 13.1(dB)\n", "CIR2=23.53 #Carrier to interference ratio from Example 13.2(dB)\n", "\n", "#Calculation\n", "\n", "ICRu=10**(-CIR1/10) #Interferece to carrier ratio for uplink\n", "ICRd=10**(-CIR2/10) #Interferece to carrier ratio for downlink\n", "\n", "ICRant=ICRu+ICRd #Overall Interferece to carrier ratio\n", "CIRant=-10*math.log10(ICRant)#Overall Carrier to interference ratio (dB)\n", "CIRant=round(CIRant,2)\n", "#Result\n", "\n", "print \"The overall carrier to interference ratio is\",CIRant,\"dB\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The overall carrier to interference ratio is 22.07 dB\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 13.4, Page 352" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#Variable Declaration\n", "\n", "SSi=4 #Initial satellite spacing(degrees)\n", "SSl=2 #Later Satellite spacing(degrees)\n", "\n", "#Calculation\n", "\n", "IIR=(29-25*math.log10(SSl))-(29-25*math.log10(SSi)) #Increase in Interference(dB)\n", "IIR=round(IIR,1)\n", "#Result\n", "\n", "print \"The degradation in downlink C/I is\",IIR,\"dB\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The degradation in downlink C/I is 7.5 dB\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 13.5, Page 356" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable Declaration\n", "\n", "f=4.2 #modualating frequency(MHz)\n", "m=2.571 #Modulation index\n", "QIF1=4.2 #Quality Impairment factor(a)\n", "QIF2=4.5 #Quality Impairment factor(b)\n", "\n", "#Calculation\n", "\n", "Dv=2*m*f #Peak to peak deviation(MHz)\n", "\n", "PR1=12.5-20*math.log10(Dv/12)-QIF1+1.1*QIF1**2 #Protection ratio for case(a)\n", "PR1=round(PR1,1)\n", "PR2=12.5-20*math.log10(Dv/12)-QIF2+1.1*QIF2**2 #Protection ratio for case(b)\n", "PR2=round(PR2,1)\n", "#Results\n", "\n", "print \"The protection ratio for quality impairment factor of 4.2 is\",PR1,\"dB\"\n", "\n", "print \"The protection ratio for quality impairment factor of 4.5 is\",PR2,\"dB\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The protection ratio for quality impairment factor of 4.2 is 22.6 dB\n", "The protection ratio for quality impairment factor of 4.5 is 25.2 dB\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 13.6, Page 363" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Variable Decalration\n", "LU=200 #Uplink propogation loss(dB)\n", "LD=196 #Downlink propogation loss(dB)\n", "GE=25 #Receiving gain of earth station(dB)\n", "GE1=25 #Transmit gain of E1 in the direction of S(dB)\n", "GS=9 #receive gain of S in the direction of E1(dB)\n", "GS1=9 #Transmit gain of satellite S1 in the direction of E(dB)\n", "GTE=48 #Transmit gain of E(dB)\n", "GRE=48 #Receive gain of E(dB)\n", "GRS=19 #Receive gain of S(dB)\n", "GTS=19 #Transmit gain of S(dB)\n", "US=-60 #Maximum power spectral density(dBJ)\n", "US1=1 #Maximum power spectral density(uJ)\n", "UE1=10 #Maximum power spectral density transmitted by earth station(uJ)\n", "UE=-50 #Maximum power spectral density transmitted by earth station(dBJ)\n", "k=-228.6\n", "#Calculation\n", "\n", "URS=UE+GTE+GRS-LU#Received power spectral density at satellite S(dB)\n", "URE=US+GTS+GRE-LD#Received power spectral density at satellite E(dB)\n", "y=URE-URS #Transmission gain for network R(dB)\n", "\n", "I1=US+GS1+GE-LD #Interference received by earth station(dB)\n", "I2=UE+GE1+GS-LU #Uplink Interference(dB)\n", "\n", "delTE=I1-k #Earth station receiver input(dBK)\n", "delTE=10**(delTE/float(10)) #Earth station receiver input(K)\n", "delTS=I2-k #Noise temperature at satellite receiver input(dBK)\n", "\n", "delTSE=y+delTS #Noise Temperature rise(dBKelvin)\n", "delTSE=10**(delTSE/10) #Noise Temperature rise(Kelvin)\n", "delT=delTSE+delTE #Equivalent noise temperature rise\n", "delT=round(delT,2)\n", "\n", "print URE,URS\n", "#Results\n", "\n", "print \"The transmission gain is\",y,\"dB\"\n", "print \"The interference levels I1 an I2 are\",I1,I2,\"dBJ respectively\"\n", "print \"The equivalent temperature rise overall is\",delT,\"Kelvin\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "-189 -183\n", "The transmission gain is -6 dB\n", "The interference levels I1 an I2 are -222 -216 dBJ respectively\n", "The equivalent temperature rise overall is 9.14 Kelvin\n" ] } ], "prompt_number": 6 } ], "metadata": {} } ] }