Virtual MIMO Array by One-Bit Transmission

This paper concentrates on an array radar system that transmits coherent signals with one-bit DAC and receives by one-bit filtering. Such an architecture realizes a virtual MIMO array radar without sending orthogonal signals. It benefits not only in transmitting in a simplified circuit at full power but also cutting down computational burden in receive, thereby making the radar suitable especially on small-size platforms, e.g. car and UAV. First, the signal model is developed under a monochromatic assumption. The one-bit signal correlation is derived by expanding the well-known arcsin law using Fourier Transform. Based on that, the correlation matrix is formulated as an infinite sum of rank-one matrix and verified to be full-rank, thereby remaining the transmit DOFs. Second, simulation on system performance is provided to compare between the phased array, the proposed array and an ideal MIMO array, validating that by converting and transmitting the correlated signal in one bit, it achieves nearly good beamforming and DOA estimation resolution as the ideal MIMO array radar.