Multiple input multiple output (MIMO) radar is a system of multiple transmit and receive antennas. Each transmit antenna radiates an arbitrary waveform independently of the other transmitting antennas. Each receiving antenna can receive these signals. Due to the different waveforms, the echo signals can be reassigned to the single transmitter and the use of multiple elements creates an enlarged size of a virtual aperture. MIMO radar systems can be used to improve spatial resolution, and they provide a substantially improved immunity to interference.
Army researchers have developed a method whereby multiple radio beamforming waveforms can be communicated in a MIMO environment. These multiple waveforms can be redundant copies of the same waveforms or different waveforms. If the multiple waveforms are transmitted concurrently without a shift, then the waveforms may not be clearly communicated. With the Army system, the waveforms shifted from one another such that clear communication occurs.
Various types of shifts can occur. In one embodiment, shifting can be time-based. With time-based shifting, signal transmission can be staggered such that the signal does not conflict with itself. In a second transmission mode, shifting can be frequency-based. Different signals with different frequencies can be transmitted simultaneously, and due to these different frequencies, signal confusion is unlikely to occur. Finally, shifting can be circular-based. With circular-based shifting, different signals can be moved with relation to time and frequency.
- The MIMO system can function without staggering a transmitter firing sequence, as is done with time-division duplex pulse compression, and the MIMO system can function without the need to span a large operational bandwidth as is done with frequency-division duplex pulse compression
- US patent 10,193,612 and US application numbers 20170093034 and 20170093035 available for license
- Potential for collaboration with Army researchers