CALCULATIONS 3 The input stream to a 2B1Q encoder is 10 01 1

CALCULATIONS:


3.    The input stream to a 2B/1Q encoder is 10 01 10 11, what is the output stream? [chapter 4]



4.    How many invalid (unused) code sequences can we have in 9B/13B encoding? [chapter 4]

Solution

3) 2B1Q(2 Binary 1 Quarternary) - data patterns of size 2 bits are encoded as one signal element belonging to a four-level signal(4 voltage levels)

out put stream will be { +3, -1, +3, +1 }

4) 9B/13B encoding- here a data pattern of size 9 bits are encoded by using 13 bits. using 9 bits we can represent 2⁹ = 512 numbers.

using 13 bits we can represent 2¹³ = 8192 numbers. in which we only need 512 number remaining are unused.

so number of invalid code sequences = 8192 - 512 = 7680.