Adaptive communications can mean any communications system, or portion thereof, that automatically uses feedback information obtained from the system itself or from the signals carried by the system to modify dynamically one or more of the system operational parameters to improve system performance or to resist degradation. In telecommunication, a communications system is a collection of individual communications networks, transmission systems, relay stations, tributary stations, and data terminal equipment (DTE) usually capable of interconnection and interoperation to form an integrated whole. ... In cybernetics and control theory, feedback is a process whereby some proportion or in general, function, of the output signal of a system is passed (fed back) to the input. ... Information is a term with many meanings depending on context, but is as a rule closely related to such concepts as meaning, knowledge, instruction, communication, representation, and mental stimulus. ... In chemistry and biology, degradation is the decomposition of a chemical compound by stages, with well-defined intermediate products. ...

The modification of a system parameter may be discrete, as in hard-switched diversity reception, or may be continuous, as in a predetection combining algorithm. In electronics, diversity reception refers to a method for improving reception of a radio signal, typically achieved by the use of dual receivers whose antennas are located in physically distinct locations (which can be less than a metre apart). ...