Answer 7.7
The code rate is defined as the ratio of the k input
bits to a block, divided by the n output bits of a block. Assuming that all of the
additional bits in the coded stream are attributable to the block coder (that is, none
are for framing, etc), then this must also be equal to the ratio of input bit rate to
output bit rate. The code rate = 12000/20000 = 3/5.
The redundancy of the code is defined as (1 code
rate) = 2/5.