Satellite Coordination Calculation & Software

 Presentation / Satellite Coordination Calculation & Software Date Submitted: 04 October 2001 Written by RPC Telecommunications. Website: http://www.rpctelecom.com ExcellentGoodAveragePoorVery Poor   Rate This Article A lecture covering satellite coordination calculation. Both the software, and manual sides of calculation are covered. Comment On This Article
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 -Section 1 Coordination Tasks -Section 2 Link & Interference Analysis -Section 3 Protection Ratio Analysis -Section 4 Databases, Data Gathering and Processing -Section 5 ITU Software Tools -Section 6 Proprietary Software Tools -Section 7 Conclusions
 Link & Interference Analysis Link budget refresher: Received Carrier Power: Pr = Pt + Gt – Lp + Gr (dBW) Received Noise Power: Pn = 10 log (k T B) (dBW) Carrier to Noise Ratio: C/N = Pt – Pn = Pt + Gt – Lp + Gr – 10 log (T) - 10 log (B) – 10 log (k) (dB) Carrier to Interference refresher: Received Wanted Carrier Power: Pw = Pt + Gt (θ) – Lp + Gr (φ) (dBW) Received Interfering Carrier Power Pi = P’t + G’t(θ’) – L’p + Gr(φ’) (dBW) So carrier to interference ratio: C/I = Pw – Pi = [Pt + Gt (θ) – Lp + Gr (φ)] – [P’t + G’t(θ’) – L’p + Gr(φ’)] Normally simplify by assuming that Lp = L’p. Note that the Gr terms both refer to the same antenna (the receiving system gain). Define receive antenna discrimination, Dr = Gr (φ) - Gr (φ’), typically –3 or –4 dB for a satellite receive antenna, generally much higher, say +20 to +40 dB for an earth station receive antenna. So simplify terms: C/I = Pt + Gt (θ) + Dr – P’t – G’t(θ’) (dB) This is a very simple equation; satellite to satellite coordination is not technically difficult to analyse! Some additional complications to bear in mind: Pt and P’t can be power spectral densities (dBW/Hz) or powers (dBW). If Pt and P’t are densities then strictly you have calculated Co/Io not C/I (Co/Io ~ C/I for digital carriers). If Pt and P’t are powers then they may have different bandwidths - normalise C/I inside the bandwidth of the wanted carrier.
 Next: Section 3 - Protection Ratio Analysis

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