Energy Efficiency of Angle of Arrival estimation in Massive MIMO Systems

• Published in: IEEE transactions on communications Vol. 70; no. 6; p. 1
• Main Authors: Arash, Masoud, Mirghasemi, Hamed, Stupia, Ivan, Vandendorpe, Luc
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-06-2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Angle of Arrival; Angular resolution; Antenna arrays; Antenna Selection; Antennas; Channel models; Cramer-Rao bounds; CRLB; Efficiency; Estimation; Localization; Localization Efficiency; Location awareness; Lower bounds; Massive MIMO; MIMO communication; Monte Carlo methods; Signal classification
• ISSN: 0090-6778; 1558-0857
• DOI: 10.1109/TCOMM.2022.3170444

In the next generation of wireless systems, massive Multiple Input Multiple Output (MIMO) offers high angular resolution for localization. By virtue of large number of antennas, Angle of Arrival (AoA) of User Terminals (UTs) can be estimated accurately. Measurements of Dense Multipath Channel (DMC) indicate multipath signals contribute up to 95% of total link power. This fact urges the necessity of studying the contribution of multipath signals accompanying dominant path in AoA estimation. We obtain a deterministic form for Cramer-Rao Lower Bound (CRLB) in multi-user scenario when contribution of multipath signals is considered. We do this when the multipath signals are independent and identically distributed (i.i.d) with arbitrary distribution. Then, we redefine a localization efficiency function for multi-user scenario and optimize it with respect to (w.r.t) the number of antennas. When only a subset of available antennas is used, we prove that CRLB can be minimized w.r.t which set is used. An antenna selection strategy that minimizes CRLB is proposed. As a benchmark, we apply the proposed antenna selection to MUltiple SIgnal Classification (MUSIC) algorithm and study its efficiency. Numerical results validate the accuracy of our analysis and show significant improvement in efficiency when the proposed antenna selection is employed.