Malte Schellmann

Huawei Technologies German Research Center · Advanced Wireless Technology Lab

As the telecommunication industry is increasing its commitment to reduce its harmful environmental impacts, energy efficiency and a low carbon footprint are becoming new criteria for a successful implementation of 5G and beyond. This paper argues that Intelligent Reflecting Surfaces (IRS) in combination with few Transmit Receive Points (TRPs) in in...

Future factories will rely on highly reliable wireless communication among the plenty of devices and the network. The 5G networks enable ultra-reliable low-latency communication (URLLC) service to address the reliability and latency requirements in factories, where device-to-device (D2D) connections can provide additional means for improving commun...

This paper investigates the resource allocation algorithm design for wireless systems assisted by large intelligent reflecting surfaces (IRSs) with coexisting enhanced mobile broadband (eMBB) and ultra reliable low-latency communication (URLLC) users. We consider a two-time scale resource allocation scheme, whereby the base station's precoders are...

This paper investigates a deployment of intelligent reflecting surfaces (IRS) in a scenario of industrial IoT communication , characterized by data transmission with high reliability under low latency constraints. In this scenario, channel diversity from independent radio links is of supreme importance, which can be enriched by IRS assisted links....

In this paper, we focus on large intelligent reflecting surfaces (IRSs) and propose a new codebook construction method to obtain a set of pre-designed phase-shift configurations for the IRS unit cells. Since the complexity of online optimization and the overhead for channel estimation for IRS-assisted communications scale with the size of the phase...

In this paper, we focus on large intelligent reflecting surfaces (IRSs) and propose a new codebook construction method to obtain a set of pre-designed phase-shift configurations for the IRS unit cells. Since the complexity of online optimization and the overhead for channel estimation scale with the size of the phase-shift codebook, the design of s...

Fifth generation wireless networks will play a crucial role in the digitization of factories. Smart factories demand ultra-reliable low-latency communication (URLLC) services to ensure a defect-free uninterrupted production system. In our earlier work, we have proposed a sidelink-assisted cooperative retransmission scheme, in which the neighbouring...

This chapter provides insights into key aspects of the radio interface design for vehicle‐to‐everything (V2X) communications for connected automated driving and connected road user services. A key technology component in the 5G NR system is the application of beamforming techniques with narrow beams in the mm‐wave spectrum to overcome the dominant...

Fortuna is the connected automated vehicle prototype built by the fortiss research institute in the course of the project PROVIDENTIA. In the project, an intelligent infrastructure prototype is created along a 2.5 km stretch on the highway A9 north of the city of Munich, Germany. This paper presents the vehicle Fortuna and illustrates the requireme...

Technologies for the autonomous driving have reached a level of maturity which enables its realization in the very near future. Incidents like the lethal Tesla car crash in 2017 or the accident of the Uber vehicle in March 2018 show, however, that it is not sufficient for a vehicle to rely solely on its on-board sensors. Communication between vehic...

This chapter ventures in detail into antenna design, analog, digital and hybrid beamforming, covers novel physical layer (PHY), media access control (MAC), design paradigms and specific solutions for serving and multiplexing the main service types envisioned for 5th generation (5G). The support of multiple antennas both at the base station (BS) and...

The fifth generation of cellular communication systems is foreseen to enable a multitude of new applications and use cases with very different requirements. A new 5G multiservice air interface needs to enhance broadband performance as well as provide new levels of reliability, latency and supported number of users. In this paper we focus on the mas...

OFDM-based waveforms with filtering functionalities are considered key enablers for a flexible air-interface design for multi-service support in future mobile systems. By allowing for the flexible configuration of physical layer parameters according to the diverse requirements of a service, these waveforms enable the in-band coexistence of differen...

This paper proposes a unified way of describing 5G air interface (AI) design proposals using a 5G service/frequency map based on work carried out as part of 5G-PPP/H2020 project “METIS-II”. It then crucially proposes a design framework and suitability assessment process for 5G AI candidates. The proposed assessment methodology focuses on “harmoniza...

In this paper, we present pulse shaped OFDM as an enabler for a flexible PHY design of the air interface for 5G. After introducing the waveform details and its degrees of freedom provided for the system design, we describe the suitable parameterizations to be considered for addressing the diverse requirements envisaged for future 5G systems, which...

Written by leading experts in 5G research, this book is a comprehensive overview of the current state of 5G. Covering everything from the most likely use cases, spectrum aspects, and a wide range of technology options to potential 5G system architectures, it is an indispensable reference for academics and professionals involved in wireless and mobi...

5th generation mobile networks will have to cope with a high degree of heterogeneity in terms of services, mobility, number of devices and so on. Thus, diverse and often contradicting key performance indicators need to be supported, but having multiple radio access technologies for multi-service support below 6 GHz will be too costly. FANTASTIC-5G...

The METIS-II project envisions the design of a new air interface in order to fulfil all the performance requirements of the envisioned 5G use cases including some extreme low latency use cases and ultra-reliable transmission, xMBB requiring additional capacity that is only available in very high frequencies, as well as mMTC with extremely densely d...

Written by leading experts in 5G research, this book is a comprehensive overview of the current state of 5G. Covering everything from the most likely use cases, spectrum aspects, and a wide range of technology options to potential 5G system architectures, it is an indispensable reference for academics and professionals involved in wireless and mobi...

In filterbank multicarrier systems with offset QAM signaling (FBMC/OQAM), real-field orthogonality is usually not sufficient to yield a frequency isolation of two resource blocks with different MIMO precoding for spatial multiplexing or beamforming. In this paper, we propose a novel scheme to avoid inter-block interference by adopting single band (...

This paper considers the scenario of massive machine type communication (MTC) in cellular uplink for short packet traffic. For this traffic type, the closed loop Timing Advance (TA) adjustment process applied in current LTE uplink introduces significant overhead in signaling and energy consumption. We propose to pulse shape the OFDM signals using t...

By application of pulse shaping, the FBMC (Filter Bank Multi Carrier) based offset-QAM-OFDM (OQAM-OFDM) modulation scheme offers a new degree of freedom in designing mobile communication systems. In this contribution we investigate the coexistence performance in terms of interference isolation of individually configured sub-bands, i.e. individual p...

In the context of spectrum sharing, a loss in spectral efficiency is incurred due to required guard bands needed for a desired co-channel interference level between systems. Our main interest is to show whether FTN signaling can recover the loss of spectral efficiency (SE) due to guard bands by adjusting the symbol duration and tolerating ISI in pr...

For future communication systems, filter bank multicarrier schemes offer the flexibility to increase spectrum utilization in heterogeneous wireless environments by good separation of signals in the frequency domain. To fully exploit this property for frame detection and synchronization, the advantage of the filter bank should be taken at the receiv...

Filterbank multi-carrier with offset quadrature amplitude modulation (FBMC/OQAM) avoids the usage of the cyclic prefix (CP) by using more localized prototype filters. However, channel estimation in highly frequency selective channels is very challenging, especially for the scattered pilots due to the intrinsic interference leaked from the neighbori...

Faster than Nyquist (FTN) signaling is a nonorthogonal transmission scheme, in which the pulses appear faster than the rate known from the Nyquist criterion. The FTN signaling offers a higher data rate compared to Nyquist signaling but results in intersymbol interference due to the violation of the Nyquist theorem. In this paper, we investigate the...

Currently deployed mobile communication systems are designed to deliver a proper Quality of Service (QoS) only in certain channel environments. The necessary channel adaptivity is utilized by adaptive modulation and coding schemes by giving up channel capacity. For transmissions in dispersive channels theory predicts a performance gain, when the pu...

Theory predicts a gain in transmission performance, when adapting pulse shapes of Offset Quadrature Amplitude Modulation (OQAM) Orthogonal Frequency Division Multiplexing (OFDM) systems to delay and Doppler spread in doublydispersive channels. Here we investigate the quantitative gains in reconstruction quality and bit error rate (BER) with respect...

Scenarios envisaged for mobile communication systems beyond 2020 imply that future applications and services will impose highly diverse requirements on the system design. To appropriately respond to these requirements while ensuring an efficient usage of available spectrum and system resources, the air interface of 5G system is expected to pro...

METIS is the EU flagship 5G project with the objective of laying the foundation for 5G systems and building consensus prior to standardization. The METIS overall approach toward 5G builds on the evolution of existing technologies complemented by new radio concepts that are designed to meet the new and challenging requirements of use cases today??s...

In 2020, mobile and wireless traffic volume is expected to increase thousand-fold over 2010 figures. Moreover, an increase in the number of wirelessly-connected devices to counts in the tens of billions will have a profound impact on society. Massive machine communication, forming the basis for the Internet of Things, will make our everyday life mo...

As of today, orthogonal frequency-division multiplexing (OFDM) has been the dominant technique in broadband transmission systems. However, for the application in cognitive radios, the sidelobes of rectangularly pulsed OFDM signals must be well suppressed to satisfy the rigorous spectral masks. In this context, filter-bank based multi-carrier (FBMC)...

In this paper, we study the coexistence issues of LTE systems operating in the TV white spaces. The study includes a proposal for an appropriate system design as well as a discussion on the LTE system's self-configurability to avoid potential interference to other systems when the resource allocation is made flexible. This is evaluated in terms of...

As one of the future indoor coverage solutions, this paper considers the cognitive Femtocell for LTE system [1], which can opportunistically access the TV white spaces. The paper selects a typical residential building for study case and uses the ray tracing method to obtain the channel profile in european TV bands. Through computer simulation, we d...

The mobile communication technologies beyond the third generation are characterized by flexibility. Due to rapid growth of spectrum demand, future wireless networks should be able to dynamically allocate resources to maintain the quality of service (QoS) and promote the efficient use of radio spectrum. The dynamic spectrum management is an effectiv...

A self-contained guide to coordinated multi-point (CoMP), this comprehensive book covers everything from theoretical basics to practical implementation. Addressing a wide range of topics, it highlights the potential gains of CoMP, the fundamental degrees of freedom involved and the key challenges of using CoMP in practice. The editors and contribut...

In this chapter, a practical concept for resource management in the downlink of a multi-user MIMO-OFDM system is presented, which aims at high user rates while requiring a limited amount of feedback only. An extended score-based scheduling approach guarantees a fair resource allocation to the users, ensuring that users are served even if they exper...

Multiantenna radio systems allow accessing the channel in diversity or spatial multiplexing (SMUX) mode. Adequate switching between these modes according to current channel conditions was shown to yield significant performance improvements while requiring little feedback from the receiving side. We present a transmission concept for the downlink of...

In OFDM-based space division multiple access (SDMA) systems, multiple users are served by a multiantenna base station simultaneously on the same frequency resources. In the uplink, each user's signal may be distorted by an independent carrier frequency offset (CFO), which impairs the orthogonality of the subcarrier signals and, if not properly comp...

By analytical means, this paper investigates the application of a multi-periodic preamble for the synchronization in OFDM systems, which is based on an auto-correlation of the received signal. In contrast to common system configurations, the multi-periodic preamble enables to select the two parameters correlation shift and correlation window length...

Applying spatial mode switching in channel adaptive MIMO systems promises to achieve high spectral efficiencies in practical system setups. Several studies have pointed out significant performance gains obtained in realis-tically modeled channel scenarios. We have conducted chan-nel measurements with the Berlin LTE-Advanced Testbed operated in the...

With the introduction of orthogonal frequency- division multiplexing and multiple antennas in cellular networks, there are new opportunities to adapt the transmission to propagation and interference conditions. In this article we describe a practical approach using space-frequency-selective multiuser MIMO scheduling. Frequency-selective feedback is...

Die Kombination der MIMO Mehrantennentechnik mit der OFDM Mehrträgerübertragung verspricht das Erzielen hoher spektraler Effizienzen bei moderater Komplexität von Sender- und Empfängerstrukturen. Weiterhin erlaubt das MIMO-OFDM Systemkonzept die flexible Vergabe von Übertragungsressourcen in Zeit, Frequenz und Raum an unterschiedliche Nutzer. Diese...

Multi-cellular radio systems are often limited due to the presence of cochannel interference. Proposed physical layer concepts, e.g. coordinated joint transmission and interference rejection combining, try to strengthen the signal while combating the interference. It is well known that base station cooperation yields great capacity improvement for...

We consider the downlink of a multi-user MIMO OFDM system in a cellular environment, where users are scheduled to the transmission resources in frequency and space. Targeting a practical solution, we assume the use of fixed DFT- based pre-coding beams at the base stations and linear receivers at the multi-antenna terminals. After having received fe...

In this work, we compare different pre-coding tech-niques and their performance in a cellular MIMO OFDM down-link. The first target is to determine the achievable additional beamforming gain by using a near-optium pre-coder instead of DFT-based pre-coding. In the second step, we include multi-user selection diversity, which turned out to be advanta...

In high-mobility OFDM systems, Doppler distortions cause inter-carrier interference (ICI) that may degrade the system performance severely. Although thoroughly studied, hardly any approaches for ICI estimation and compensation exist that maintain the OFDM-specific subcarrier-wise signal processing and thus provide a solution with reasonable demands...

Channel adaptive transmission in multi-user MIMO systems is seen as a promising concept to achieve high spectral efficiencies in future radio networks: Based on feedback on actual channel conditions, the base station allocates transmission resources to the user terminals where they can support high data rates. However, due to the delay between eval...

Information theory predicts huge performance gains in terms of spectrum efficiency by using cooperative transmission from multiple base stations. Cooperation eliminates inter-cell interference and it enables a higher channel rank. The isolated cell capacity is an upper bound for unlimited backbone capacity, infinite signal processing power and infi...

Multi-cellular radio systems are often limited due to the presence of cochannel interference. Physical layer concepts as e.g. interference rejection combining, optimize the receiver side and thus strengthen the signal while combating the interference at the terminal side only. It is well known that joint transceiver optimization, i.e. coordinated j...

We consider synchronization techniques required to enhance the cellular network capacity using base station cooperation. In the physical layer, local oscillators are disciplined by the global positioning system (GPS) and over the backbone network for outdoor and indoor base stations, respectively. In the medium access control (MAC) layer, the data...

Cellular radio systems are often limited due to the presence of cochannel interference. Basically, radio systems may be operated by utilizing asynchronous or synchronous downlink transmission from all base stations in the system, where synchronization between terminals and their serving base station is mandatory in both concepts. We provide a compa...

In high-mobility OFDM systems, Doppler distortions cause inter-carrier interference (ICI) that may degrade the system performance severely. Solutions to combat these distortions usually result in an extensive amount of signal processing at the receiver , where the favourable properties of the OFDM signal structure in frequency domain are no longer...

We consider feedback design for the integration of multi-user MIMO in cellular mobile radio systems. Feedback is given by the mobile ter-minals, which report beam indices referring to a set of fixed pre-coding beams and corresponding signal to signal to interference and noise ratio (SINR) for different supported spatial transmission modes. The SINR...

Multicellular radio systems are often limited due to the presence of cochannel interference. Proposed physical layer concepts, e.g. coordinated joint transmission and interference rejection combining, try to strengthen the signal while combating the interference. However, the performance may be limited by the available channel knowledge. We provide...

Doppler distortions caused by mobile users destroy the orthogonality of the signals used in OFDMA systems, causing severe interferences which may limit the system performance. We propose a scheme to estimate and compensate the Doppler distortions in OFDMA systems, where users are assigned subbands of contiguous subcarriers, so called chunks. The sc...

Multi-antenna radio systems which are capable to select the spatial transmission mode according to the current channel conditions promise to achieve high transmission rates. Considering multiple users, the rates can be further increased if the multi-user diversity is properly utilized. However, fairness constraints have to be taken into account her...

We demonstrate that the fundamental capacity scaling law of multiple-input multiple-output radio systems, being proportional to the minimum of the number of receive and transmit antennas, holds also for the interference-limited multi-user multi-cell downlink scenario. It can be realized by using a sophisticated combination of physical and medium ac...

We demonstrate how virtual MIMO techniques can be implemented in a next-generation mobile communication system. In order to test basic principles, joint spatiotemporal processing of two users has been implemented in an uplink scenario. A prerequisite of virtual MIMO is accurate synchronization. It is shown that the carrier frequency offset can be r...