Bahria University Karachi Campus
BS (CS) – 4th Semester
Course Code: CEN 222
Course Instructor: Naureen Farhan
Assignment – 02
Date: 30th Dec, 2021
[CLO 1, CLO 2]
Max. Marks: 10
Q1) Given a channel with an intended capacity of 20 Mbps, the bandwidth of the channel is 3 MHz.
Assuming white thermal noise AWGN (-120 dBm), what signal-to-noise ratio is required to
achieve this capacity?
Q2) Suppose a transmitter produces 50 W of power.
a. Express the transmit power in units of dBm and dBW.
b. If the transmitter’s power is applied to a unity gain antenna with a 900-MHz carrier
frequency, what is the received power in dBm at a free space distance of 100 m?
c. Repeat (b) for a distance of 10 km.
d. Repeat (c) but assume a receiver antenna gain of 2.
Q3) A light signal is travelling through a fiber. What is the delay in the signal if the length of the fiberoptic cable is 5 m, 500 m, and 1 Km (assume a propagation speed of 2 x 108 m/s)?
Q4) Consider a transmission system using frequency division multiplexing. What cost factors are
involved in adding one more pair of stations to the system?
Q5) A pseudorandom number generator uses the following formula to create a random series:
Nj +1 = (5 +7Nj) mod 17-1
In which Nj defines the current random number and Nj +1 defines the next random number. The
term mod means the value of the remainder when dividing (5 + 7Nj) by 17.