Table 1 Link budget analysis for downlink LEO OFL.

Transmitted power \(P_T\)

20 dBm

Free space loss \(L_{FS}\)

− 265.32 dB

Transmitter telescope gain \(G_T\)

121.78 dB

Receiver telescope gain \(G_R\)

117.41 dB

Extinction loss \(\tau _{ATM}\)

− 3.80 dB

Turbulence-induced beam spreading loss \(L_{SR}\)

–

Pointing loss \(L_{pointing}\)

− 2.53 dB

Scintillation margin \(L_{SI}\)

− 9.13 dB

SMF coupling efficiency \(\eta _F\)

− 13.74 dB

Received optical power \(P_R\)

− 36.98 dBm