An Interference Cancellation System for a Hopping HF Military Communication Network

Interference Cancellation Systems (ICSs) are utilized to reduce strong undesired signals, which desensitize receiving equipment, in situations that are difficult to handle using filter technology. This paper describes the application of an ICS to provide isolation between colocated non-coordinated frequency hopping HF transmitters and receivers. It is modular in design with built-in self diagnostics and can be powered from a single DC supply. The system operates from 2 to 30 Mhz, and provides a minimum of 76dB of isolation between the receiver and transmitter. It acquires to within 20dB of the specified isolation 200usec after each frequency hop. The design criteria for the ICS will be discussed and the performance results for the initial production units will be given.