DARPA wants more efficient, jam-resistant RF communications

For over a century the military has used radio frequencies for communications, command and control, navigation and radar detection. As the RF spectrum gets more crowded, and as the Defense Department’s reliance on it increases, the military has to deal with two problems: malicious jamming and signal fratricide.

In an effort to find solutions to these problems, the Defense Advanced Research Projects Agency has released a presolicitation for advanced microsystems and techniques for jamming-resistant RF communications under its Hyper-wideband Enabled RF Messaging (HERMES) program.

More specifically, DARPA is looking for proposals that examine the feasibility of  wideband spread-spectrum RF communications that have greater than 10 GHz of instantaneous bandwidth and operate below 20 GHz to employ coding gain and spectral filtering, as well as reduce atmospheric absorption.

The studies will focus on two primary research thrusts with the overall goal of achieving more than 70 decibels of jammer suppression:

System Architecture Development. This includes an investigation of system architectures, signal processing techniques, spectrum regulation, and channel propagation effects that will conclude with a demonstration using commercial technologies. New techniques should be able to yield upwards of a 30-decibel improvement in operational signal-to-jammer ratio with minimal impacts on system sensitivity.

Photonic Receiver Development. The proposals should lead to the development of novel receiver technologies that will pave the way for integrated filters and active cancellation techniques, and conform to hand-held radio weight, size and power requirements. DARPA is especially interested in technologies that could scale power consumption and size for a handheld device.

The need to develop these technologies is driven by increased consumer demand for the electromagnetic spectrum. U.S. government rights to the spectrum have been reduced and fragmented as frequency bands are allocated for commercial use. According to the solicitation, the federal government has exclusive rights to only 1.4 percent of the total spectrum, making military spectrum management a near-nightmare. The military is thus increasingly worried about signal fratricide or interference, possibly denying important strategic and tactical radio links.

The smaller available slices of the spectrum also make it easier for adversaries to target specific bands for malicious jamming. Adversaries have been vigorously developing electronic warfare capabilities with the intent to attack the U.S. military’s C4ISR systems.

DARPA expects multiple awards from the solicitation; the response due date is currently set for Aug. 12, 2014.

DARPA’s search for new technologies is in line with DOD’s spectrum management strategy that was released earlier this year. The plan, which complied with President Obama’s 2010 order to make an addition 500 MHz of spectrum available for commercial use by 2020, called for new technologies capable of more efficient use of the spectrum and reduced risk of interference.