Date: 8 March 2023
Time: 7:00 PM ET (New York Time)
Title: Power Scaling of Uplink Massive MIMO Systems with Arbitrary-Rank Channel Means
This webinar will investigate the uplink achievable rates of massive multiple-input multiple-output (MIMO) antenna systems in Ricean fading channels, using maximal-ratio combining (MRC) and zero-forcing (ZF) receivers, assuming perfect and imperfect channel state information (CSI). In contrast to previous relevant works, the fast-fading MIMO channel matrix is assumed to have an arbitrary-rank deterministic component as well as a Rayleigh-distributed random component. We derive tractable expressions for the achievable uplink rate in the large-antenna limit, along with approximating results that hold for any finite number of antennas. Based on these analytical results, we obtain the scaling law that the users’ transmit power should satisfy, while maintaining a desirable quality of service. In particular, it is found that regardless of the Ricean K-factor, in the case of perfect CSI, the approximations converge to the same constant value as the exact results, as the number of base station antennas (M) grows large, while the transmit power of each user can be scaled down proportionally to 1/M. If CSI is estimated with uncertainty, the same result holds true but only when the Ricean K-factor is non-zero. Otherwise, if the channel experiences Rayleigh fading, we can only cut the transmit power of each user proportionally to 1/√M. In addition, we show that with an increasing Ricean K-factor, the uplink rates will converge to fixed values for both MRC and ZF receivers.
Qi Zhang (M’16) received the B.S. degree in electrical and information engineering from the Nanjing University of Posts and Telecommunications (NJUPT), Nanjing, China, in 2010 and the Ph.D. degree in communication and information systems from NJUPT, in 2015. She was a Postdoctoral Research Fellow with the Singapore University of Technology and Design, Singapore, from 2015 to 2017, a Visiting student in Hong Kong University of Science and Technology, from 2014 to 2015. She is currently with the faculty of the Jiangsu Key Laboratory of Wireless Communications, NJUPT. Her research interests include massive MIMO systems, space–time wireless communications, random access, and Internet of Things. Dr. Zhang received the Excellent PhD Thesis of NJUPT award in 2015.