An adaptive transmit power control system for digital airborne communications

The authors describe a technique for adaptively controlling the transmission power of a digital airborne low-probability-of-intercept (LPI) radio. The purpose of adaptive transmit power control (ATPC) is to reduce and maintain transmit power at the minimum level required for tactical communications among specific aircraft within a 20 km radius. A closed-loop half-duplex system using an interrogate/transpond operation is suggested as a suitable candidate for the ATPC network. It is determined that the short duration of the interrogation pulse limits its detectability. The interrogation pulse is shown to have approximately a 10 dB advantage over a non-ATPC system transmission of 0.8 (wideband radiometer)