Massive machine-type communications (mMTC) is one of the main three focus areas in the
5th generation (5G) of wireless communications technologies to enable connectivity of a …

This paper considers massive access in massive multiple-input multiple-output (MIMO)
systems and proposes an adaptive active user detection and channel estimation scheme …

This article presents a comprehensive study on the emerging near-space communications
(NS-COM) within the context of space–air–ground–sea integrated network (SAGSIN) …

This article studies massive access in cell-free massive multi-input multi-output (MIMO)-
based Internet of Things and solves the challenging active user detection (AUD) and …

Non-orthogonal multiple access (NOMA) can support more users than OMA techniques
using the same wireless resources, which is expected to support massive connectivity for …

Non-orthogonal multiple access (NOMA) is an emerging research topic in the future fifth
generation wireless communication networks, which is expected to support massive …

Non-orthogonal multiple access (NOMA) has been regarded as one of the promising key
technologies for future 5G systems. In the uplink grant-free NOMA schemes, dynamic …

Massive machine-type communication (mMTC) is a newly introduced service category in 5G
wireless communication systems to support a variety of Internet-of-Things (IoT) applications …

Grant-free non-orthogonal multiple access has recently gained significant attention for
reducing signaling overhead in machine-type communications. In this context, compressed …

This paper concerns uplink grant-free nonorthogonal multiple access, where the
handshaking procedure is not required to reduce control signaling overhead and …