Optimal Transmit Antenna Selection in Underlay Spectrum Sharing

Spectrum sharing is essential to meet the ever-increasing demand of high wireless data rates. New wireless standards such as 5G and IEEE 802.11be WiFi are being designed to support spectrum sharing. Our research focuses on the underlay mode of spectrum sharing, in which a low priority secondary user transmits simultaneously in the same spectrum as a higher priority primary user so long as the interference seen by the primary user is not excessive.

Our work had led to the development of new and optimal transmit antenna selection rules that improve the secondary user’s performance while adhering to the interference constraints. Our research studies the combined impact of the power adaptation, interference constraint, channel state information, and the number of primary users on the structure of the optimal selection rules. They reduce the average symbol error probability of the secondary system by one to two orders of magnitude compared to the selection rules existing in the literature.

References:

R. Sarvendranath and N. B. Mehta, “Exploiting power adaptation with transmit antenna selection for interference-outage constrained underlay spectrum sharing,” IEEE Trans. Commun., vol. 68, no. 1, pp. 480-492, Jan. 2020.

R. Sarvendranath and N. B. Mehta, “Statistical CSI Driven Transmit Antenna Selection and Power Adaptation in Underlay Spectrum Sharing Systems,” IEEE Trans. Commun., vol. 69, no. 5, pp. 2923-2934, May 2021.

R. Sarvendranath and N. B. Mehta, “Impact of multiple primaries and partial CSI on transmit antenna selection for interference-outage constrained underlay CR,” IEEE Trans. Wireless Commun., vol. 18, no. 2, pp. 942-953, Feb. 2019.