Phased-MIMO Radar: A Tradeoff Between Phased-Array and MIMO Radars

Abstract

We propose a new technique for multiple-input multiple-output (MIMO) radar with colocated antennas which we call phased-MIMO radar. The new technique enjoys the advantages of MIMO radar without sacrificing the main advantage of phased-array radar which is the coherent processing gain at the transmitting side. The essence of the proposed technique is to partition the transmitting array into a number of subarrays that are allowed to overlap. Then, each subarray is used to coherently transmit a waveform which is orthogonal to the waveforms transmitted by other subarrays. Coherent processing gain can be achieved by designing a weight vector for each subarray to form a beam towards a certain direction in space. Moreover, the subarrays are combined jointly to form a MIMO radar resulting in higher resolution capabilities. The substantial improvements offered by the proposed phased-MIMO radar technique as compared to previous techniques are demonstrated analytically and by simulations through analysis of the corresponding beampatterns and achievable output signal-to-noise-plus-interference ratios.Both analytical and simulation results validate the effectiveness of the proposed phased-MIMO radar.

Joint Phased-MIMO and Nested-Array Beamforming for Increased Degrees-of-Freedom

“…In contrast, phased-array has good direction gain but without spatial diversity gain. To overcome these disadvantages, intermediates between MIMO and phased-array are investigated by jointly exploiting their benefits [9][10][11]. Particularly, a transmit subaperturing approach was proposed in [11] for MIMO radar.…”

“…The basic idea is to form multiple transmit beams which are steered toward the same direction [12]. In [9], the authors proposed a phased-MIMO technique, which enjoys the advantages of MIMO array without sacrificing the main advantages of phased-array in coherent processing gain. That is to say, phased-MIMO array offers a tradeoff between conventional phased-array and MIMO array.…”

“…Inspired by the phased-MIMO [9] and nest-array [29], this paper proposes a joint phased-array and nested-array beamforming based on the difference coarray processing and spatial smoothing for increased DOFs and consequently more sources can be resolved. The main contribution of this work can be summarized as follows: (1) a joint phased-array and nested-array beamforming is proposed.…”

Digital Beamforming on Receive in Elevation for Spaceborne Hybrid Phased-Mimo Sar

“…Multiple-input multiple-output (MIMO) radar system with multidimensional waveform encoding [13][14][15] is to employ multiple antennas for emitting several orthogonal waveforms which is better than traditional phased-array radar, but loosing coherent processing gain at the transmitting array. Recently, a compromise formulation between the coherent processing gain offered by the phased-array radar and the advantages of the MIMO radar, e.g., the waveform diversity, was proposed and named as Hybrid MIMO Phased Array Radar (HMPAR) [16][17][18][19][20]. HMPAR is to partition the transmitting array into multi-arrays which is allowed to overlap, and each of these subarrays is in turn used to emit the orthogonal signal through transmitting beamforming towards arbitrary direction in space.…”

Low complexity receiver design for MIMO-radar

“…The coherent processing between the individual phasedarray at the fusion center is a practical issue. The configuration in [8] divides the given transmit antennas into K overlapping sub-arrays, where 1 ≤ K ≤ n T . Each sub-array transmits the waveform, which is orthogonal to the waveforms transmitted by the other sub-arrays.…”