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EXERCISE ABOUT CABTE LINES AND REGENERATTVE REPEATERS (25l03l20t4lLet be given a baseband coaxial cable connection, whose kilometric attenuationAo=3dB/Km@1MHz. Let's suppose to transmit a data stream at a bit-rate of 24 Mb/s, usingraised-cosine-filtered 16-PAM modulation (roll-off 25%1. Under this hypothesis it is required to:1) Compute the maximum length of the connection allowing to transmit the aforesaid datastream without inter-symbol interference (assume that the cutoff frequency of the cableconnection is its 3dB bandwidth);Let's suppose now to transmit the same data stream with the same modulation format over thesame cable connection, at a distance of 2 Km. The transmission is performed by means of a serlesof regenerative repeaters placed every 400 meters of cable segment. The noise figure of eachregenerative repeater is 7dB. Distortion equalization is supposed to be standard. Under this newhypothesis it is required to:

Compute the minimum transmission power required to each regenerative repeater in order toreceive the data stream at destination with a bit-error-rate less or equal to 10-6;Compute the same quantity in the case that the repeaters used in the link are not regenerative(the noise figure is the same than that of regenerative repeaters used at point 2).

isa

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