{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Chapter No.3 : The cellular concept system design fundamentals"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 3.1 Page No.61"
]
},
{
"cell_type": "code",
"execution_count": 14,
"metadata": {
"collapsed": false
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"outputs": [
{
"name": "stdout",
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"text": [
"\n",
" The number of channels available per cell for 4-cell reuse system = 165 channels\n",
"\n",
" One control channel and 160 voice channels would be assigned to each cell.\n",
"\n",
" \n",
" The number of channels available per cell for 7-cell reuse system = 95 channels\n",
"\n",
" Each cell would have one control channel, four cells would have 90 voice channels and three cells would have 91 voice channels.\n",
"\n",
" \n",
" The number of channels available per cell for 12-cell reuse system = 55 channels\n",
"\n",
" Each cell would have one control channel, eight cells would have 53 voice channels and four cells would have 54 voice channels.\n"
]
}
],
"source": [
"from math import ceil\n",
"# To compute the number of channels available per cell for a)four-cell reuse system a)seven-cell reuse system a)12-cell reuse system\n",
"\n",
"# Given data\n",
"B=33*10**6# # Total bandwidth allocated to particular FDD system in Hz\n",
"Bc=25*10**3# # Bandwidth per channel in Hz\n",
"Nc=2# # Number of simplex channels\n",
"Bc=Bc*Nc# # Channel bandwidth in Hz\n",
"\n",
"Ntotal=B/Bc# # Total number of channels\n",
"\n",
"#a) To compute the number of channels available per cell for four-cell reuse system\n",
"N=4# # frequency reuse factor\n",
"chpercell=Ntotal/N# # number of channels available per cell for four-cell reuse system\n",
"\n",
"# Displaying the result in command window\n",
"print \"\\n The number of channels available per cell for 4-cell reuse system = %0.0f channels\"%(chpercell)\n",
"print \"\\n One control channel and 160 voice channels would be assigned to each cell.\"\n",
"\n",
"# b) To compute the number of channels available per cell for seven-cell reuse system\n",
"N=7# # frequency reuse factor\n",
"chpercell=ceil(Ntotal/N)# # number of channels available per cell for seven-cell reuse system\n",
"\n",
"# Answer is varrying due to round-off error\n",
"\n",
"# Displaying the result in command window\n",
"print \"\\n \\n The number of channels available per cell for 7-cell reuse system = %0.0f channels\"%(chpercell)\n",
"print \"\\n Each cell would have one control channel, four cells would have 90 voice channels and three cells would have 91 voice channels.\"\n",
"\n",
"# c) To compute the number of channels available per cell for 12-cell reuse system\n",
"N=12# # frequency reuse factor\n",
"chpercell=Ntotal/N# # number of channels available per cell for seven-cell reuse system\n",
"\n",
"# Displaying the result in command window\n",
"print \"\\n \\n The number of channels available per cell for 12-cell reuse system = %0.0f channels\"%(chpercell)\n",
"print \"\\n Each cell would have one control channel, eight cells would have 53 voice channels and four cells would have 54 voice channels.\""
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 3.2 Page No.72"
]
},
{
"cell_type": "code",
"execution_count": 15,
"metadata": {
"collapsed": false
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"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"\n",
" Signal to noise ratio for n=4 with frequency reuse factor N=7 = 18.66 dB\n",
"\n",
" Signal to noise ratio for n=3 with frequency reuse factor N=7 = 12.05 dB\n",
"\n",
" Signal to noise ratio for n=3 with frequency reuse factor N=12 = 15.56 dB\n",
"\n",
" Since SIR is for n=3 with frequency reuse factor N=7 greater than the minimum required, so N=12 is used.\n"
]
}
],
"source": [
"from math import sqrt, log10\n",
"from __future__ import division\n",
"# To find frequency reuse factor for path loss exponent (n) a)n=4 b)n=3\n",
"\n",
"# Given data\n",
"SIdB=15# # Signal to interference(dB)\n",
"io=6# # Number of cochannel cell\n",
"\n",
"# For n=4\n",
"n1=4# # Path loss exponent\n",
"N1=7# # First consideration: frequency reuse factor N=7\n",
"DR1=sqrt(3*N1)# # Co-channel reuse ratio\n",
"si1=(1/io)*(DR1)**n1# # Signal to interference\n",
"sidB1=10*log10(si1)# # Signal to interference(dB)\n",
"\n",
"# For n=3\n",
"n2=3# # Path loss exmponent\n",
"si=(1/io)*(DR1)**n2# # Signal to interference for first consideration: frequency reuse factor N=7\n",
"sidB=10*log10(si)# # Signal to interference(dB)\n",
"\n",
"N2=12# # second consideration : frequency reuse factor N=12 since sidB