Distributed Coherent Communications

Vadum will develop and simulate a low-overhead beamforming protocol for Distributed Coherent Communications (DC2) using non-developmental waveforms that will enable bi-directional transmit (TX) and receive (RX) squad-to-squad and squad-to-base station beamforming. The Vadum approach uses transparent applique firmware and/or minor modifications to currently-deployed tactical MANET protocols to implement an innovative Master-Slave architecture with no increase in radio size, weight, and power (SWAP). The Master-Slave architecture uses direct power measurement and closed-loop feedback to achieve beamforming with no requirement for GPS position information and no limit on number of participating nodes. Coherent gain is achieved using a novel hybrid of experimentally demonstrated techniques for phase synchronization, power control, and implicit time and frequency synchronization via low-latency retransmission. The hybrid approach enables better performance with respect to link closure, response to dynamic channel impairments, and power/bandwidth efficiency.