Baseband signal processing algorithms
Baseband signal processing algorithms would refer to any algorithm that is written after you have down converted your RF or IF signals to baseband(signal centered around 0 Hz).

Example : Suppose there is a difference in the RF carrier frequency between the transmitter and receiver . So , after downconversion at the receiver , there will be a frequency offset (equal to Tx Center Frequency - Receive Center Frequency) in the baseband signal . In this case , an algorithm to estimate/correct this frequency offset on the baseband signal can be termed as a baseband signal processing algorithm.

Other baseband algorithms could include estimation/correction of Timing Offset and IQ Impairements to name a few.