Abstract: In a composite concentration system of the type utilizing a time division system in which voice signals are digitized and then concentrated in a traffic, there are provided a first subscriber line interface means of a first type which connects subscriber lines directly to subscriber line interface circuits, a second subscriber line interface means of a second type which connects subscriber lines to subscriber line interface circuits via a space division concentration switch and a time division concentration switch connected to the first and second subscriber line interface means via switching interfaces.

Abstract: The invention is used in a receiver for a communication system, which transmits periodically occurring digital signals over a pair of orthogonally related polarized waves. Horizontal signals from one of the orthogonal waves are applied to a first input terminal of an equalizer in the receiver. Vertical signals from the other of the orthogonal waves are applied to a second input terminal. An individually associated, cascaded plurality of delay circuits is coupled to each of the input terminals. The delay in each of the delay circuits is equal to the time spacing between the occurring signals. Therefore, a plurality of the recurring digital signals appear simultaneously at the outputs of each of the delay circuits. A variable attenuator, individually associated with the output of each delay circuit, is adjusted to pass an incremental signal responsive to each of the occurring signals appearing simultaneously at the outputs of the delay circuits.