Millimeter-Wave Antenna Array Diagnosis with Partial Channel State Information

Abstract

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.

Blind Diagnosis for Millimeter-wave Large-scale Antenna Systems

“…Hence, one can generate the fault-free channel vector h using (2) and subtract it from the received signal, and the impact of channel can be eliminated. A recent work [13] relaxes the CSI requirement in the sense that it only requires the AOA of each sub-path (i.e., θ l ), whose main idea is to project the received signal onto the null space of AOAs and thus the impact of channel can also be eliminated.…”

“…We adopt the success probability as the performance metric, which is defined as the probability that the status of all antenna elements is correctly identified. For comparison, we adopt the diagnostic techniques proposed in [5] (denoted as Eltayeb18) and [13] (denoted as Medina20) as benchmark techniques, which require full and partial CSI, respectively.…”

“…In order to distinguish antenna failure from channel fading, the above diagnostic techniques rely on perfect CSI to generate fault-free reference signal, which can be challenging to acquire in the presence of antenna failures. Recently, a diagnostic technique proposed in [13] relaxes the CSI requirement, which only needs the angle-of-arrival (AOA) of each sub-path in the channel, i.e., partial CSI. However, acquiring the AOA of each sub-path still can be a challenging task for a potentially faulty system since faulty antenna elements will change array geometry and distort radiation pattern, which makes AOA estimation highly unreliable.…”