A satellite communication system processes a plurality of input signals to generate beamformed signals, drives a plurality of nonlinear power amplifiers with the beamformed input signals to produce RF signals for transmission; and transmits the RF signals with a plurality of Tx antenna elements. Conversion to and from linear signals to and from nonlinear or digitized signals is performed. Temporal or spatial decorrelation of the beamformed signals is employed to reduce the impact of intermodulation products. In some cases the power amplifiers are nonlinear, and can be one-sided or two-sided and produce two or three distinct output levels.

A distributed antenna system includes a master unit including a downlink RF input operable to receive an RF input signal from a downlink port of a base station, a first optical port, and a second optical port. The distributed antenna system also includes a first remote unit coupled to the first optical port. The first remote unit comprises a downlink antenna port and a first uplink antenna port and a second remote unit coupled to the second optical port of the master unit. The second remote unit comprises a downlink antenna port and a second uplink antenna port. The master unit is operable to transmit a first RF signal associated with the first RF uplink signal to a first uplink port of the base station and transmit a second RF signal associated with the second RF uplink signal to a second uplink port of the base station.

A communication verification system is provided. The communication verification system includes a local transmitting-end unit, a remote receiving-end unit, and a repeater device. The local transmitting-end unit is set to a first computing mode and outputs an initial value. The remote receiving-end unit is set to a second computing mode. The repeater device receives the initial value from the local transmitting-end unit and outputs an initial value to the remote receiving-end unit according to the second computing mode. The repeater device receives and stores a computation result from the remote receiving-end unit, and then outputs a confirmation signal to the local transmitting-end unit according to the first computing mode. The repeater device outputs the computation result to the local transmitting-end unit for verification when the repeater device receives a query signal from the local transmitting-end unit.