TY - GEN
T1 - Throughput optimal beam alignment in millimeter wave networks
AU - Hussain, Muddassar
AU - Michelusi, Nicolo
N1 - Funding Information:
M. Hussain and N. Michelusi are with the School of Electrical and Computer Engineering, Purdue University. email: {hussai13,michelus}@purdue.edu. This research has been funded by NSF under grant CNS-1642982.
Publisher Copyright:
© 2017 IEEE.
PY - 2017/8/30
Y1 - 2017/8/30
N2 - Millimeter wave communications rely on narrow-beam transmissions to cope with the strong signal attenuation at these frequencies, thus demanding precise beam alignment between transmitter and receiver. The communication overhead incurred to achieve beam alignment may become a severe impairment in mobile networks. This paper addresses the problem of optimizing beam alignment acquisition, with the goal of maximizing throughput. Specifically, the algorithm jointly determines the portion of time devoted to beam alignment acquisition, as well as, within this portion of time, the optimal beam search parameters, using the framework of Markov decision processes. It is proved that a bisection search algorithm is optimal, and that it outperforms exhaustive and iterative search algorithms proposed in the literature. The duration of the beam alignment phase is optimized so as to maximize the overall throughput. The numerical results show that the throughput, optimized with respect to the duration of the beam alignment phase, achievable under the exhaustive algorithm is 88.3% lower than that achievable under the bisection algorithm. Similarly, the throughput achievable by the iterative search algorithm for a division factor of 4 and 8 is, respectively, 12.8% and 36.4% lower than that achievable by the bisection algorithm.
AB - Millimeter wave communications rely on narrow-beam transmissions to cope with the strong signal attenuation at these frequencies, thus demanding precise beam alignment between transmitter and receiver. The communication overhead incurred to achieve beam alignment may become a severe impairment in mobile networks. This paper addresses the problem of optimizing beam alignment acquisition, with the goal of maximizing throughput. Specifically, the algorithm jointly determines the portion of time devoted to beam alignment acquisition, as well as, within this portion of time, the optimal beam search parameters, using the framework of Markov decision processes. It is proved that a bisection search algorithm is optimal, and that it outperforms exhaustive and iterative search algorithms proposed in the literature. The duration of the beam alignment phase is optimized so as to maximize the overall throughput. The numerical results show that the throughput, optimized with respect to the duration of the beam alignment phase, achievable under the exhaustive algorithm is 88.3% lower than that achievable under the bisection algorithm. Similarly, the throughput achievable by the iterative search algorithm for a division factor of 4 and 8 is, respectively, 12.8% and 36.4% lower than that achievable by the bisection algorithm.
KW - beam alignment
KW - initial access
KW - Markov decision process
KW - Millimeter Wave
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U2 - 10.1109/ITA.2017.8023460
DO - 10.1109/ITA.2017.8023460
M3 - Conference contribution
AN - SCOPUS:85030978192
T3 - 2017 Information Theory and Applications Workshop, ITA 2017
BT - 2017 Information Theory and Applications Workshop, ITA 2017
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 2017 Information Theory and Applications Workshop, ITA 2017
Y2 - 12 February 2017 through 17 February 2017
ER -