Impact of Subcarrier Allocation and User Mobility on the Uplink Performance of Multiuser Massive MIMO-OFDM Systems

This paper considers the uplink performance of a multi-user massive multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) system with mobile users. Mobility brings two major problems to MIMO-OFDM system: inter carrier interference (ICI) and channel aging. In practice, it is common allot multiple contiguous subcarriers user as well schedule users on each subcarrier. Motivated by this, we consider general subcarrier allocation scheme derive expressions for ICI power, signal plus noise ratio achievable sum-rate, taking into account due We show that incurs near-constant power depends linearly number per user, nearly independently how UEs distribute their across subcarriers. Further, exploit coherence bandwidth reduce length pilot sequences required estimation. both zero-forcing maximal-ratio combining at receiver compare respective sum-rate performances. either case, proposed leads significantly higher sum-rates compared previous work, owing property reduced overhead.