Key Channel Properties
- Bandwidth (B): The range of frequencies that can be transmitted over a channel.
- Signal (S): The signal is the information that is being transmitted over the channel.
- Noise (N): The noise is the unwanted information that is being transmitted over the channel.
Nyquist Limit
Maximum symbol rate is 2B symbols/sec.
If there are V signal levels, max bit rate is:
R = 2B log_2(V) bits/sec
Shannon Capacity
Capacity (C) limit is the maximum lossless information carrying rate of a channel.
C = B log_2(1 + S/N) bits/sec
- There is some rate at which we can transmit information over a channel without error.
- Assuming noise is fixed, we can increase the bandwidth to increase the capacity, albeit with diminishing returns.
- Increasing bandwidth increases capacity linearly
Can't beat the Shannon limit