Unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UGVs) are massively growing areas in the defense sector. In these applications, field-programmable gate arrays (FPGAs) are being used more and more instead of conventional processors because of the demanding real-time processing capabilities required (e.g. detect and avoid systems ; DAA ).

Another area where FPGAs truly shine is in the communication systems for these vehicles. Multi-band, frequency-agile,  cognitive radio, anti-jamming, custom OFDM waveforms, interference suppression – these are all being considered. At the same time, there is the challenge of reducing latency while maximizing data throughput. For example, decisions must be made quickly, vision systems must transmit better image quality, etc.

The costs of these systems must also be considered. Existing systems are equipped with multiple radios, each with its own purpose. A software-defined radio (SDR) can combine all the communication systems into one, with configurable hardware device, thus reducing system and maintenance costs.

Lastly, data security and encryption techniques are also a real challenge. Defense communication systems must be designed to be as secure as possible – break-ins from enemies aren’t acceptable on the battlefield. To combat this,  custom and unique waveform modulation techniques combined with deep encryption techniques are used. One can’t just re-use an existing standard wireless protocol and package it into these devices as it would be too easy to crack.

Nutaq’s FPGA-based SDR systems like the PicoSDR and the ZeptoSDR are well-equipped to help defense research centers accelerate the development of new waveform standards. Both systems include an FPGA-based SISO/MIMO OFDM PHY layer reference design, allowing for wireless real-time video transmission between two RF nodes with a QAM64 modulation and easy customization. For additional information, see the following videos:

• http://nutaq.com/blog/video-cognitive-ofdm
• http://www.nutaq.com/blog/videogetting-started-nutaqs-ofdm-qam64-reference-design-10-minutes
• http://www.nutaq.com/blog/video-ofdm-reference-design-overview

With the PicoSDR platform, users have the ability (if required) to program the FPGA from within the well-known Simulink graphical environment, which accelerates and drastically simplifies FPGA simulation and the deployment of wireless applications. For more information, see the following blog posts and papers:

• http://www.nutaq.com/blog/complete-model-based-pc-fpga-sdr-development-environment-gnu-radio
• http://nutaq.com/sites/default/files/papers/sdr/picosdr_gnuradio_paper_022313.pdf
• http://www.nutaq.com/blog/success-story-using-nutaq%E2%80%99s-model-based-design-kit-mbdk-rapid-prototyping-nanosatellite

Lastly, both SDR systems are completely integrated with the popular GNU Radio toolkit. Both systems offer embedded processor options (ARM-based or i7-based) to install and run GNU Radio. Additionally, both systems enable a remote host PC to access radios as peripherals from the GNU Radio environment. For information about using GNU Radio with Nutaq platforms, see the following blog posts and video:

• http://www.nutaq.com/blog/gnu-radio-plug-adp-64
• http://www.nutaq.com/blog/what-gnu-radio