A Multi-Service Oriented Multiple-Access Scheme for Next-Generation Mobile Networks

One of the key requirements for fifth-generation (5G) cellular networks is their ability to handle densely connected devices with different quality of service (QoS) requirements. In this article, we present multi-service oriented multiple access (MOMA), an integrated access scheme for massive connections with diverse QoS profiles and/or traffic patterns originating from both handheld devices and machine-to-machine (M2M) transmissions. MOMA is based on a) stablishing separate classes of users based on relevant criteria that go beyond the simple handheld/M2M split, b) class dependent hierarchical spreading of the data signal and c) a mix of multiuser and single-user detection schemes at the receiver. Practical implementations of the MOMA principle are provided for base stations (BSs) that are equipped with a large number of antenna elements. Finally, it is shown that such a massive-multiple-input-multiple-output (MIMO) scenario enables the achievement of all the benefits of MOMA even with a simple receiver structure that allows to concentrate the receiver complexity where effectively needed.Comment: 6 pages, 3 figures, accepted to the European Conference on Networks and Communications (EuCNC 2016

On performance of multi-user massive MIMO for 5G and beyond

5G New Radio (NR) is the latest radio access technology (RAT) developed by 3GPP for the 5G mobile network. 5G NR and beyond is expected to play a key role in Cyber-Physical Systems as it will deliver significantly faster, more reliable and much lower latency connections to enable wireless control applications. 5G will support three fundamental application scenarios, enhanced Mobile BroadBand (eMBB), Ultra-Reliable and Low deployment Latency Communication (URLLC), and massive Machine-Type Communication (mMTC). mMTC is of particular importance as it forms the basis of IoT, whereas URLLC will support mission-critical applications such as autonomous robotics. The commercial roll-out of 5G is planned in phases with challenging new vertical deployments as the technology is still evolving and little practical experience is available yet. Massive MIMO is a vital enabling technology for 5G NR, enhancing reliability and data rates in challenging environments. It is one of the technologies having a low carbon emission rate as it exploits the resources in an optimal way, hence enabling more sustainable and greener networks. In this paper, we investigate the performance of two MIMO precoding techniques in terms of achievable sum rates for massive MIMO. Simulation experiments show that Zero Forcing (ZF) precoding outperforms Maximum Ratio Transmission (MRT) precoding for the given scenario and assumed conditions

Downlink MIMO-NOMA with and without CSI: A short survey and comparison

Non-orthogonal multiple access (NOMA) concatenated with multiple-input multiple-output (MIMO) or with massive MIMO, has been under scrutiny for both broadband and machine-type communications (MTC), even though it has not been adopted in the latest 5G standard (3GPP Release 16), being left for beyond 5G. This paper dwells on the problems causing such cautiousness, and surveys different NOMA proposals for the downlink in cell-centered systems. Because acquiring channel state information at the transmitter (CSIT) may be hard, open-loop operation is an option. However, when users clustering is possible, due to some common statistical CSI, closed-loop operation should be exploited. The paper numerically compares these two operating modes. The users are clustered in beams and then successive interference cancellation (SIC) separates the power-domain NOMA (PD-NOMA) signals at the terminals. In the precoded closed-loop system, the Karhunen-Loève channel decomposition is used assuming that users within a cluster share the same slowly changing spatial correlation matrix. For a comparable number of antennas the two options perform similarly, however, while in the open-loop downlink the number of antennas at the BS is limited in practice, this restriction is waived in the precoded systems, with massive MIMO allowing for a larger number of clusters.info:eu-repo/semantics/acceptedVersio