If i have eight voltage levels (0v, 2, 4, 6, 8, 10, 12, 14v) with a bandwidth of 125MHz, what is my max data rate in Mbps? And if I increase to 200MHz?
If the question is how to find max data rate or channel capacity (C), given the bandwidth (B) and number of voltage levels (M), it is C = 2*B*log(M)
For 125MHz, C = 2*125*log(8) = 750 Mbps. For 200MHz, C = 2*200*log(8) = 1200 Mbps.
Refer http://computernetworkingsimplified.in/physical-layer/relationship-bandwidth-data-rate-channel-capacity/ for details