9.5 Tools for Link Budget Calculations

Any science pocket calculator will do fine, but it is preferable to us a spreadsheet type of link budget calculator, such as the example in Tables 9.3 and 9.4. Most of my tools are done using standard Excel for windows. Dedicated tools for link budget calculations are available, but the flexibility of a standard Excel spreadsheet makes it very easy to upgrade and maintain. You can easily integrate the results of other calculations, such as cascaded noise (as shown in Table 9.2) or power per carrier, into your link budget tool if it is all based on Excel.

Table 9.2 Simple cascaded noise calculator using Excel

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Table 9.3 Link budget tool in Excel, GSM uplink

MS transmitter
MS Tx power 33 dBm
MS antenna gain 0 dBi
EiRP 33 dBm
DAS receiver
BS noise figure 3 dB
DAS noise figure 0 dB
DAS passive loss 35 dB
System noise figure 38 dB
Thermal noise floor −121 dBm
Interference −120 dBm
Service SNR requirement 9 dB
DAS antenna gain 2 dBi
BS sensitivity 76 dBm
The RF channel
Log-normal shadow fading 10 dB
Multipath fading margin 6 dB
Body loss 3 dB
Total margin 19 dB
Rx minimum level 57.0 dBm
Maximum allowable path loss 90 dB
Service radius from antenna 23 m

Table 9.4 Indoor ‘model’ calculator, the first homemade tool I ever made for indoor designs

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