Low SWaP Directional Terminals through Difference Co-array Processing

ABSTRACT: In this Phase II effort Silvus Technologies proposes to develop and field test fully digital beamforming techniques on a 16 antenna array integrated with Silvus MIMO radios and CDL terminals from BAE Systems. This effort will advance the TRL of both linear and non-linear digital techniques. Non-linear beamforming technique use the recent fundamental innovations in difference co-array signal processing. Depending on antenna element placement, difference co-array processing has the potential to provably create O(N^2) spatial degrees of freedom using only O(N)antenna elements. This is a huge step forward from any state of the art system. The antenna arrays elements have non-uniform (aperiodic) spacing between them to achieve the above theoretical degrees of freedom (DoFs). However unlike traditional aperiodic antenna array design which depends purely on computational approaches, the proposed aperiodic array approaches have a closed form solution, enabling designers to cross validate experimental outcomes with theoretical predictions. In Phase II Silvus will test a prototype modular digital beamformer system in a dynamic air-to-air environment. BENEFIT: There are numerous applications of the ground breaking technology development enabling O(N^2 ) spatial degrees of freedom with just O(N) antenna elements in the fields of wireless communications (both commercial and military), RADAR, electronic warfare, RF geo-localization, Anti-jam equipment etc. Additional DoFs can be used to enhance spectral efficiency of tactical ad hoc networks by signaling in the spatial dimension, to compute direction of arrival of a large number of RF sources, to spatially null interference from jammers, to track a large number of targets using low SWaP RADARs etc. Today's advanced computing platforms can easily fit the required signal processing to realize such gains in DoF. Example Air Force applications: The E-3 AWACS rotodome contains a large phased array radar. The proposed technology will enable creation of small form factor phased array radars. The rotodome causes unwanted drag, a reduced size rotodome will increase the mission life of E-3 AWACS on a single fuel tank. Commercial Applications: Multi-user downlink in cellular systems uses smart antenna beamforming. The innovations described in this proposal can provide considerably higher throughput with the same antenna arrays. Silvus & #1048758; expertise in MIMO and smart antenna processing is of particular value here as 5G cellular systems have adopted MIMO and cost effective and smart MIMO antennas are viewed as a future need.