Theory 86/Energy Limits/Communications
Transmission Has a Per-Bit Floor
The claim
The energy per bit of a communication link is bounded below by the ratio of noise to bandwidth, so widening bandwidth lowers the floor but raises total power.
01Mechanism
Shannon capacity sets the bits per second per hertz; the energy per bit is power divided by capacity, which has a minimum.
02Prediction
Energy per bit should bottom out at an optimal bandwidth.
03Refutation
Energy per bit falling indefinitely with bandwidth would remove the floor.