Waveforms for LOS/BLOS communications

The national implementation of cryptographic algorithms safeguards all of a radio’s characteristics that are relevant for national security. After approval of the software by the security authorities, the waveform can be downloaded onto the software defined radio (SDR) in compliance with the security regulations. This flexibility opens up additional opportunities for enabling interoperability of the communications technology between partners: For example, interoperability between the armed forces (joint missions), between allies (combined missions) and even with public safety organizations.

Waveform development in the context of software defined radio has to address topics beyond waveform development for legacy systems (e.g. for HF modems). The key requirements of modern software defined radio based waveform development are met by using a defined approach to waveform development for all waveform development steps. The radio and radio platform software is based on the SCA 2.2.2 standard.

Waveforms

The different waveforms of software defined radios need to cover all required applications/use cases such as situational awareness, live video transmission, command and control, and simple voice communications. There are different design aspects to be considered when developing a waveform for tactical communications:

• Robustness and mobility
• Jam resistance
• Low probability of detection and interception
• High data rate
• High range and coverage
• Networking capability (MANET) and quality of service
• Adaptability

The individual properties partly influence each other physically. Different waveforms are needed to adapt the technical settings to the mission scenario.
Example: A waveform suitable for air-ground communications must cope with the high speed of the airborne platform, and therefore must include Doppler shift compensation. This is not necessary for ground-ground communications.