4D-PAM5 code #3
The questions below refer to the 4D-PAM5 encoder-decoder pair used in Ethernet 1000Base-T.
a. Explain why each encoder (channel) symbol can convey a total of nine bits.
b. With what speed (in bps) are the information bits fed to the encoder?
c. After every how many information bits must the encoder transmit one 4D symbol?
d. Calculate and explain the resulting symbol rate.
e. Suppose that the following sequence of symbols is allowed and must be transmitted: (-2, -1, +1, +2), (0, +1, -1, 0), (-2, -1, +1, +2), (0, +1, -1, 0), . . . . Draw the corresponding waveform in each pair of wires using the clock period, T, of part (b) above, as the time unit.