In a digital modulation channel, what is the uniform distribution of energy as a function of frequency called?

The uniform distribution of energy as a function of frequency in a digital modulation channel is referred to as spectral density. This concept describes how the signal's power is distributed across various frequencies, indicating the amount of energy per frequency unit.

In the context of digital communications, understanding spectral density is crucial as it helps in analyzing how signals behave in a given frequency spectrum. A uniform spectral density means that energy is spread evenly across the frequency range of interest, which can impact system performance in terms of both bandwidth usage and interference management.

In contrast, signal strength typically pertains to the amplitude of the signal and does not focus on its frequency distribution. The noise floor represents the lowest level of noise present in a system and is not a description of energy distribution across frequencies. Channel capacity is related to the maximum rate at which data can be transmitted over a channel, influenced by factors like bandwidth and noise but does not define the distribution of energy in frequency.