  Large antenna arrays enable directional precoding for Millimeter-Wave
(mmWave) systems and provide sufficient link budget to combat the high
path-loss at these frequencies. Due to atmospheric conditions and hardware
malfunction, outdoor mmWave antenna arrays are prone to blockages or complete
failures. This results in a modified array geometry, distorted far-field
radiation pattern, and system performance degradation. Recent remote array
diagnostic techniques have emerged as an effective way to detect defective
antenna elements in an array with few diagnostic measurements. These
techniques, however, require full and perfect channel state information (CSI),
which can be challenging to acquire in the presence of antenna faults. This
paper proposes a new remote array diagnosis technique that relaxes the need for
full CSI and only requires knowledge of the incident angle-of-arrivals, i.e.
partial channel knowledge. Numerical results demonstrate the effectiveness of
the proposed technique and show that fault detection can be obtained with
comparable number of diagnostic measurements required by diagnostic techniques
based on full channel knowledge. In presence of channel estimation errors, the
proposed technique is shown to out-perform recently proposed array diagnostic
techniques.
