Subject: Data Communication
Date: 15 December 2020. Time: 10:20 AM to 11:50 AM
1. (Basic Concepts)
A. Explain three control parameters of cosine (or sine) wave. B. How is each control parameter used to encode binary bits?
C. Explain Shannon’s Formula and Nyquist’s Formula for calculating channel capacity. 2. (Scrambling and digital encoding)
A. Generate 16 bits pseudo-random sequence using the following LFSR (Linear-Feedback
Shift Register.
B. Generate 16 bits of scrambling data for 0000 0000 1111 1111
C. Draw NRZ, NRZ-I (NRZ-Mark), and MLT-3 pulse diagrams for the result (B)
3. (QAM)
A. Calculate I and Q value for 4 red dots in the constellation.
4. (Frame)
A. What is multiplexing?
B. Compare characteristics of Synchronous TDM and Statistical TDM. C.
, (1) encode and (2) decode data { (10), (01) } using the chann
el code (1,-1,1,-1) for (10) and (1,-1,-1,1) for (0,1). D. In SDM, MIMO (Multiple Input Multiple Output) technology is widely used. What are
their primary usages?
A. Draw the Trellis Diagram for the following convolutional encoder
B. Encode the result of the first 8 bits of the result of Question 2 (B). C. Support that the received data r has bit error at position bit2 and 6 (the bit number
is counted from 0). What is the corrected sequence selected by the Viterbi algorith
m?
D. Calculate the Hamming distance of the corrected sequence.