Designing a High speed Wireless Data Link

Designing a High speed Wireless Data Link
Line of Sight Link Budget Analysis
a) FSPL (dB) for 2.4GHz and 5.8GHz frequencies over 5Km and 10 Km distance.
FPSL (dB) = 20log10(d) + 20log10(f) + 32.45
Thus, for 2.4 GHz over 5 Km:
FPSL (dB) = 20log10 (5) + 20log10 (2.4) + 32.45
= 20(0.698970004) +20(0.380211242) + 32.45
= 54.033624921 dB
For 2.4 GHz over 10 Km:
FPSL (dB) = 20log10 (10) + 20log10 (2.4) + 32.45
= 20(1) +20(0.380211242) + 32.45
= 60.054224834 dB
For 5.8 GHz over 5 Km:
FPSL (dB) = 20log10 (5) + 20log10 (5.8) + 32.45
= 20(0.698970004) +20(0.763427994) + 32.45
= 61.697959958 dB
For 5.8 GHz over 10 Km:
FPSL (dB) = 20log10 (10) + 20log10 (5.8) + 32.45
= 20(1) +20(0.763427994) + 32.45
= 67.718559871 dB
FSPL (dB)
Distance (Km) 2.4 GHz 5.8 GHz
5 54.033624921 61.697959958
10 60.054224834 67.718559871

b) Link Budget Analysis For The Wireless System
General Formulae required in Link Budget Analysis:
Link Margin = Received Power - Receiver sensitivity
Received Power (dBm) = Transmitted Power (dBm) + Gains (dB) - Losses (dB)
Gains (dB) = Transmitter Antenna Gain + Receiver Antenna Gain
Customized Formulae Based on our scenario:
Since loss due to cabling and connectors is negligible in our case, Received Power will be:
Received Power (dBm) = Transmitted Power (dBm) + Gains (dB) – FSPL (dB)
Since we are also using the same Antenna, Antenna gain for Transmitter is the same as that of
receiver. Thus:
Gains (dB) = 2 * Antenna Gain
Calculations for Our Scenario:
Gains (dB) = 2 * (Antenna Gain)
= 2 (24dBi)
= 2 (24dB) ; since 1dB = 1dBi
= 48 dB
FSPL (dB) = 20log10 (d) + 20log10 (f) + 32.45
= 20log10 (5) + 20log10 (5.8) + 32.45
= 20(0.698970004) +20(0.763427994) + 32.45
= 61.697959958 dB
Received Power (dBm) = Transmitted Power (dBm) + Gains (dB) – FSPL (dB)
= +23dBm + 48dB - 61.697959958 dB
= 9.302040042 dBm
Link Margin = Received Power - Receiver Sensitivity
= 9.302040042 dBm - (-72dBm)
= 81.302040042 dBm