ThD2 – Modulation and Massive MIMO

Thursday, 20 June 2019, 16:00-17:30, Room 2


Session chairMartine Liénard (University of Lille, France)


Achieving Ultra-Reliable Communication via CRAN-enabled Diversity Schemes

Binod Kharel, Onel Luis López, Hirley Alves and Matti Latva-aho (University of Oulu, Finland)
Internet of things is in progress to build a smart society, and wireless networks are critical enablers for many of its use cases. In this paper, we present a multi-coordinated transmission scheme to achieve ultra-reliability for critical machine-type wireless communication networks. We take advantage of diversity, which is fundamental for dealing with fading channel impairments, and for achieving ultra-reliable region of operation in order of five 9’s as defined by 3GPP standardization bodies. We evaluate an interference-limited network composed of multiple remote radio heads that are allowed to cooperate, by keeping silence thus reducing interference, or by performing more elaborated strategies such as maximal ratio transmission, in order to serve a user equipment with ultra-reliability. We provide extensive numerical analysis and discuss the gains of cooperation by the centralized radio access network.


A Non-orthogonal Waveform Design with Iterative Detection and Decoding for Narrowband IoT Applications

Sumaila Mahama (University of York, United Kingdom (Great Britain)); Yahya Jasim Harbi (University of Kufa, Iraq); Alister G. Burr and David Grace (University of York, United Kingdom (Great Britain))
Narrowband Internet of Things (NB-IoT) was proposed by 3GPP in Release 13 to provide low power wide area connections to a high-volume of devices. With the millions of devices expected to connect to 5G through its massive machinetype communication use case, the strict orthogonality and synchronization requirement of cyclic-prefix orthogonal division multiplexing (CP-OFDM) will demand a very large amount of control information between devices and the core network. To overcome this challenge, we study a new air interface for NBIoT, which utilizes a non-orthogonal multicarrier transmission scheme. The waveform considered in this work is filter-bank muilticarrier with quadrature amplitude modulation (FBMCQAM). The loss of orthogonality in FBMC-QAM results in severe levels of intrinsic interference. Iterative detection and decoding (IDD) using low density parity check (LDPC) encoding and decoding is implemented together with iterative interference cancellation (IIC) to remove the inherent interference and improve the BER rate performance. Simulation results indicate that the proposed IDD receiver can effectively improve BER performance under time-varying channels.


Distributed Spatial Modulation Aided NOMA

Amir Shehni and Mark F. Flanagan (University College Dublin, Ireland)
In this paper, a novel cooperative diversity protocol based on the association of non-orthogonal multiple access (NOMA) and distributed spatial modulation (DSM) is introduced. In the proposed protocol, two source symbols are multiplexed in the power domain, while one source symbol obtains a diversity gain due to its being relayed according to the DSM principle; this doubles the data rate for the source-to-destination link as compared with conventional DSM. We propose two demodulators for use at the destination: an error-aware demodulator which is robust to demodulation errors at the relays, and a suboptimal demodulator which assumes error-free demodulation at the relays. Simulation results demonstrate that while the proposed protocol achieves a source data throughput equal to that of a full-duplex system, its BER performance also significantly outperforms the full-duplex relaying benchmarks of successive relaying and virtual full-duplex DSM.


Quantized Massive MIMO Networks Under Channel Correlation and CSI Mismatch

Murat Temiz (University of Manchester, United Kingdom (Great Britain)); Emad Alsusa (Manchester University, United Kingdom (Great Britain)); Laith Danoon (University of Manchester, United Kingdom (Great Britain))
This study examines the performance of the multi-user multiple-input-multiple-output (massive MIMO) systems with 1-bit, 2-bit and 3-bit analogue to digital converters (ADCs) under channel correlation and channel state information (CSI) errors. The OFDM modulated uplink with QPSK, 16QAM and 32QAM schemes are considered for the communication between the base station (BS) and the user equipment (UEs). The BS antenna array is assumed to be uniform linear (1D) or uniform rectangular (2D) arrays. Zero-Forcing (ZF) receiver has been employed by the BS due to its simplicity and superior performance over other linear receivers. Furthermore, we consider the square root raised cosine filter (SRRC) to enhance the performance of the low-resolution ADC systems. The results show that the resolution of ADCs mainly determines the modulation scheme and having a high-level channel correlation or CSI mismatch requires a higher resolution ADCs. Furthermore, it has been shown that the SRRC filter enhances the system performance even with low-resolution ADCs.


Impact of Polarization Diversity in Massive MIMO for Industry 4.0

Frédéric Challita (University of Lille & IEMN Lab, France); Pierre Laly and Martine Liénard (University of Lille, France); Emmeric Tanghe and Marwan Yusuf (Ghent University, Belgium); Wout Joseph (Ghent University/IMEC, Belgium); Davy P Gaillot (University of Lille, France)
The massive polarimetric radio channel is evaluated in an indoor industrial scenario at 3.5 GHz using a 10×10 uniform rectangular array (URA). The analysis is based on (1) propagation characteristics like the average received power and the power to interference ratio from the Gram matrix and (2) system-oriented metrics such as sum-rate capacity with maximum-ratio transmitter (MRT). The results clearly show the impact of polarization diversity in an industrial scenario and how it can considerably improve different aspects of the system design. Results for sum-rate capacity are promising and show that the extra degree of freedom, provided by polarization diversity, can optimize the performance of a very simple precoder, the MRT.


Downlink Coordinated Beamforming Policies for 5G Millimeter Wave Dense Networks

Marios Gatzianas (Aristotle University of Thessaloniki & International Hellenic University, Greece); Georgios Kalfas and Christos Vagionas (Aristotle University of Thessaloniki, Greece); Agapi Mesodiakaki (Aristotle University of Thessaloniki (AUTH), Greece)
A key technology of the upcoming Fifth Generation (5G) networks, which is expected to crucially affect the achieved system capacity, is Coordinated Multipoint (CoMP), where multiple base stations collaborate with each other to mitigate inter-cell interference. In this paper, we present a Coordinated Beamforming (CB) CoMP policy for dense fixed-wireless millimeter wave networks. This policy, which is based on a standard stochastic optimization methodology, explicitly accounts for realistic antenna radiation patterns and stochastic packet arrivals, in addition to channel state fluctuations. It performs both user scheduling as well as proper radiation pattern selection in order to control interference and can be easily extended to include additional MAC and PHY layer controls. For comparison purposes, two other round-robin policies are proposed. Simulation results indicate that the proposed CB policy is able to achieve a throughput gain up to 2X per user.