How do you calculate coding rate?
The code rate is R = k/n. The Hamming distance d between two codewords is the number of positions by which they differ. For example, the codewords 110101 and 111001 have a distance of d = 2. If valid codewords are always at least a distance d = 2 apart, then it is always possible to detect a single error.
How long does signal change what is called this ratio for seconds?
Baud rate refers to the number of signal or symbol changes that occur per second.