Describing the four phase psk detector

Question

Question 1) How does a communication satellite differ from a communication relay?

Question 2) Describe why it is not possible to have a direct optical communication link between earth station and communication satellite. What are the different atmospheric attenuations that come in optical communication link?

Question 3) Why the satellite uplink frequency is different from downlink frequency?

Question 4) Write down the different interferences that may affect satellite link performance.

Question 5) What do you mean by threshold in FM detector?

Question 6) Write down the name of method of digital modulation technique mainly used in digital satellite communication.

Question 7) How the bit error rate is different from symbol error rate?

Question 8) Name the photodetectors being used in optical communication.

Question 9) Write down the significant parameters that control the design of earth station.

Question 10) Write down the uses of military satellites.

Question 11) Write down the advantages and disadvantages of satellite communication. Give the reasons that optical fibers in spite of being high bandwidth channel, satellite communication has the edge over it.

Question 12) Derive general link equation. Give the expressions for C/N and G/T ratio.

Question 13)a) Describe the four phase PSK detector with block diagram.

b) A synchronous satellite has T as the side real period of rotation of its primary body, Tp (the period in any fixed reference coordinate system). It must be noted that for earth Tp is not 24 hours because in one day the earth both rotates once around its polar axis and completes 1/36524 of the annual earth orbit around sun. Determine the period for geosynchronous satellite.

Question 14) Describe the DA-FDMA (SPADE) system. In what ways it is different from simple FDMA system.

Question 15) For the satellite earth station receiver working on 4GHz, the typical a variety of gains and noise temperatures are T_in =50 K, T_RF=50 K, T_m =500 K, T_IF =1000 K, G_RF = 23dB, G_m =0 dB, G_IF=30 dB. Compute the system noise temperature.

Question 16)a) Describe DA-TDMA system.

b) Explain TDMA super frame. How it is different from simple TDMA frame?

Question 17) Write brief notes on following:

a) Beam hopping TDMA.

b) Erlang call congestion formula.