Extra large MIMO (XL-MIMO) systems are subject to spatial non-stationarity forming visibility
regions (VRs), which leads to a sub-array-wise sparse structure of the channel matrix. When …

To support massive connectivity for sporadically active devices is a challenging task, as the
randomness of the channel and the large number of users lead to enormous increase of …

This paper addresses the problem of joint downlink channel estimation and user grouping in
massive multiple-input multiple-output (MIMO) systems, where the motivation comes from …

The quasi-static assumption of channels becomes invalid in a number of emerging
applications of massive multiple-input multiple-output (MIMO) systems with high base station …

We investigate wideband uplink channel estimation for a multi-user (MU) multiple-input
single-output (MISO) OFDM system, in which the base station (BS) is equipped with an …

In this paper, the zero-forcing and regularized zero-forcing schemes operating in crowded
extra-large MIMO (XL-MIMO) scenarios with a fixed number of subarrays have been …

This letter considers a joint user activity, channel and data estimation problem in an uplink
grant-free massive MIMO systems with low-precision analog-to-digital converters (ADCs) …

This article considers the massive access problem in an uplink cell-free multiple-input–
multiple-output (MIMO) system where massive potential users communicate with a set of …

This paper addresses wideband channel estimation in an uplink massive multiple-input
multiple-output (MIMO) system, which consists of multiple single-antenna users and a base …

In this paper, we study the problem of user activity detection and large-scale fading
coefficient estimation in a random access wireless uplink with a massive MIMO base station …