QUADRA enhancements to MINTERM [radiocommunication]

The QUADRA terminal includes embedded ECCM/LPI and nonhopped modems, voice processor, and COMSEC. The QUADRA enhancements to MINTERM add antijamming capability by providing two frequency-hopping modems, HDR and LDR (high and low data rare). HDR packetizes encrypted (KYV-5 COMSEC compatible), 2400 bit/s data and compressed speech (LPC10) such that it is compatible with MIL-STD-188-148, and therefore the AN/PRC 104B (STAJ) radio. LDR packetizes encrypted, 400 bit/s data and compressed speech such that it is compatible with the fast frequency hopping mode of the AN/PRC 104B (STAJ) radio. When the jamming threat or channel conditions are too severe to use the HDR, the LDR is used. Speech intelligibility is reduced, but it provides added jam resistance and superior bit-error-rate performance in severe channels. Extensive laboratory tests and field demonstration tests have been run using the four QUADRA terminals for the US Army and Air Force. Both voice and data communications were successfully demonstrated