Eckhard Grass

Eckhard Grass
IHP | Institute for High Performance Microelectronics · Wireless Communication Systems

About

181
Publications
47,243
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1,725
Citations
Citations since 2017
82 Research Items
681 Citations
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2017201820192020202120222023020406080100120140
2017201820192020202120222023020406080100120140
2017201820192020202120222023020406080100120140

Publications

Publications (181)
Article
Full-text available
Developments in radio detection and ranging (radar) technology have made hand gesture recognition feasible. In heat map-based gesture recognition, feature images have a large size and require complex neural networks to extract information. Machine learning methods typically require large amounts of data and collecting hand gestures with radar is ti...
Preprint
p>Belief Propagation (BP) algorithm is suitable for high-throughput decoding of polar codes due to its inherent parallelism. However, compared with Successive Cancellation (SC)-based decoding methods, BP-based schemes fall behind in terms of Bit-Error Rate (BER) performance. In this paper, a simplified stage-combined BP decoding algorithm is propos...
Preprint
p>Belief Propagation (BP) algorithm is suitable for high-throughput decoding of polar codes due to its inherent parallelism. However, compared with Successive Cancellation (SC)-based decoding methods, BP-based schemes fall behind in terms of Bit-Error Rate (BER) performance. In this paper, a simplified stage-combined BP decoding algorithm is propos...
Article
Full-text available
In this work, we propose a Deep neural network-assisted Particle Filter-based (DePF) approach to address the Mobile User (MU) joint synchronization and localization (sync&loc) problem in ultra-dense networks. In particular, DePF deploys an asymmetric time-stamp exchange mechanism between the MUs and the Access Points (APs), which, traditionally, pr...
Conference Paper
In recent years, Wi-Fi-based positioning has become more attractive, as Wi-Fi-capable devices are readily available. Additionally, some positioning methods can be easily integrated using the currently available Wi-Fi devices. In this paper, we investigate a time difference of arrival (TDoA) approach for Wi-Fi positioning. The proposed approach work...
Article
Full-text available
In past years, Parallel Sequence Spread Spectrum (PSSS) has attracted significant attention as a modulation technique for wireless communication systems targeting data rates of 100 Gb/s and beyond. PSSS allows designing high-speed baseband processors, which can be partially implemented in the analog domain. It uses multiple analog-to-digital conver...
Conference Paper
In this work, we describe analytical and empirical approaches for room geometry determination using beamsteering. The channel impulse responses were obtained both from a ray-tracing model and channel measurements. The paper presents an algorithm for object detection by means of an analysis of the impulse response of electromagnetic waves at 60 GHz...
Preprint
Full-text available
In this work, we propose a Deep neural network-assisted Particle Filter-based (DePF) approach to address the Mobile User (MU) joint synchronization and localization (sync\&loc) problem in ultra dense networks. In particular, DePF deploys an asymmetric time-stamp exchange mechanism between the MUs and the Access Points (APs), which, traditionally, p...
Conference Paper
This paper investigates chip area, clock frequency, throughput, power consumption, and energy efficiency of real-valued spreading sequences proposed for Parallel Sequence Spread Spectrum (PSSS). On the one hand, real-valued sequences cause significant hardware overhead when compared to the usually employed binary m-sequences. On the other hand, the...
Conference Paper
This paper investigates coding and modulation schemes for wireless communication based on variable-rate parallel sequence spread spectrum (PSSS). PSSS can adapt the spreading gain according to channel conditions. When this modulation technique is combined with external forward error correction (FEC), a challenge arises in adjusting the gains from F...
Conference Paper
This paper investigates signal-to-noise ratio (SNR) performance and hardware complexity of real-valued spreading sequences, which have all sequence coefficients defined in the real domain. These particular sequences can be employed for both direct-sequence spread spectrum (DSSS) and parallel sequence spread spectrum (PSSS). The simulation results r...
Conference Paper
Physical layer security is one of the trending research areas in tackling data security issues of wireless networks. The main focus of this work is to explore practically the possibilities and performance of secret key generation solutions exploiting wireless channel randomness. This paper describes the implementation of a real-time secure key gene...
Conference Paper
In this paper, we investigate the mean communication rate loss (MCRL) due to beam cusping with respect to multiple input multiple output (MIMO) spatial dimensions, beamforming codebook sizes, and beam scan spaces for beamforming operations controlled by the medium access control (MAC) layer beamforming protocol. The intractability of the analytical...
Article
Spread spectrum clocking (SSC) conventionally uses frequency modulation (FM) to suppress digital switching noise in the frequency domain. While clock-FM effectively reduces spectral noise peaks, it maintains the synchronous operation per cycle with total noise unchanged. In this paper, we introduce plesiochronous design as a general applicable de-s...
Chapter
This paper describes an approach for optimizing media streaming services in mobile environments by utilizing the fifth-generation mobile network technology (5G), including millimeter Wave (mmWave) high speed data links, 5G Edge Computing and relevant state-of-the-art media streaming standards, such as Network Based Media Processing (NBMP) and Serve...
Conference Paper
In this paper, we investigate the use of bipolar Barker sequences for high-speed wireless communication based on Parallel Sequence Spread Spectrum (PSSS) modulation. To improve bit error rate (BER) performance for PSSS, we propose median detection at the receiver or DC-offset correction at the transmitter. Both techniques cancel the influence of cy...
Article
This letter presents an analytical framework to study the distortion effect of power amplifiers (PA) in a single-stream millimetre wave (mmWave) system with a radio-frequency (RF) beamforming architecture. A third-order nonlinearity PA model is used. The impact of PA nonlinearity on the transmitter performance is evaluated by means of its normalise...
Article
This work presents experimental results for a four-stream spatial multiplexing setup in a line-of-sight (LoS) wireless backhaul scenario at 60 GHz. With optimal antenna arrangement, a highly orthogonal wireless channel with a measured condition number of 1.42 is observed, whereby the channel tap distribution shows a dominant LoS component. Two diff...
Article
Full-text available
Clock synchronization has always been a major challenge when designing wireless networks. This work focuses on tackling the time synchronization problem in 5G networks by adopting a hybrid Bayesian approach for clock offset and skew estimation. Furthermore, we provide an in-depth analysis of the impact of the proposed approach on a synchronization-...
Article
For the next generation wireless networks, backhaul links with data rates of several Gbit / s are required. Line-of-Sight-MIMO with optimally arranged antennas can exploit the full multiplexing gain of orthogonal MIMO streams to achieve high throughput, as shown in recent works utilizing the 60 GHz mm wave band. In contrast, conventional MIMO syste...
Conference Paper
Full-text available
In this work, we propose a hybrid Bayesian approach towards clock offset and skew estimation, thereby synchronizing large scale networks. In particular, we demonstrate the advantage of Bayesian Recursive Filtering (BRF) in alleviating time-stamping errors for pairwise synchronization. Moreover, we indicate the benefit of Factor Graph (FG), along wi...
Preprint
In this work, we study the joint synchronization and localization (sync&loc) of Mobile Nodes (MNs) in ultra dense networks. In particular, we deploy an asymmetric timestamp exchange mechanism between MNs and Access Nodes (ANs), that, traditionally, provides us with information about the MNs' clock offset and skew. However, information about the dis...
Article
Millimeter wave (mmWave) communication has emerged as a key technology for achieving high data-rates and low latency in 5G networks. Radio-frequency (RF) or analog beamforming is used to provide additional (beamforming) gain to compensate for propagation phenomena in the mmWave spectrum. In this letter, we analyzed the effects of residual transceiv...
Preprint
In this work, we propose a hybrid Bayesian approach towards clock offset and skew estimation, thereby synchronizing large scale networks. In particular, we demonstrate the advantage of Bayesian Recursive Filtering (BRF) in alleviating time-stamping errors for pairwise synchronization. Moreover, we indicate the benefit of Factor Graph (FG), along wi...
Preprint
In this work, we propose a hybrid approach to synchronize large scale networks. In particular, we draw on Kalman Filtering (KF) along with time-stamps generated by the Precision Time Protocol (PTP) for pairwise node synchronization. Furthermore, we investigate the merit of Factor Graphs (FGs) along with Belief Propagation (BP) algorithm in achievin...
Conference Paper
With the rise of 5G, there is an increased interest in precise localization and location-aware communication. The use of millimeter wave (mmWave) communication allows precise location estimation due to large signal bandwidths. This paper is focused on the performance analysis of Time-of-Flight (ToF) localization in the unlicensed mmWave (60GHz) ban...
Conference Paper
This paper presents a 60 GHz beamforming (BF) solution based on a 8-channel BF chip with an on-board dipole array antenna. A single BF chip has a Tx OP1dB of 1 dBm and an Rx IP1dB of -23 dBm per RF channel, occupying a silicon area of 27 mm2. The antenna array is based on eight in-line 4×1-dipole elements and it has a measured peak gain of 17 dBi a...
Conference Paper
The increasing demand for high data rates and the emergence of new data-hungry applications motivate the exploration of higher frequency bands for the beyond fifth generation (5G) wireless systems. The frequencies above 100 GHz, so-called terahertz (THz) spectrum, offer abundant communication bandwidth, hence enabling, in theory, terabit throughput...
Preprint
Full-text available
In this paper, we obtain and study typical beam entropy values for millimetre wave (mm-wave) channel models using the NYUSIM simulator for frequencies up to 100 GHz for fifth generation (5G) and beyond 5G cellular communication systems. The beam entropy is used to quantify sparse MIMO channel randomness in beamspace. Lower relative beam entropy cha...
Preprint
Full-text available
Terahertz spectrum is being researched upon to provide ultra-high throughput radio links for indoor applications, e.g., virtual reality (VR), etc. as well as outdoor applications, e.g., backhaul links, etc. This paper investigates a monopulse-based beam tracking approach for limited mobility users relying on sparse massive multiple input multiple o...
Preprint
Full-text available
This paper presents a novel radio frequency (RF) beam training algorithm for sparse multiple input multiple output (MIMO) channels using unitary RF beamforming codebooks at transmitter (Tx) and receiver (Rx). The algorithm leverages statistical knowledge from past beam data for expedited beam search with statistically-minimal training overheads. Be...
Article
The increased carrier bandwidth and the number of antenna elements expected in 5G networks require a redesign of the traditional IP-based backhaul and CPRI-based fronthaul interfaces used in 4G networks. We envision future mobile networks to encompass these legacy interfaces together with novel 5G RAN functional splits. In this scenario, a consiste...
Conference Paper
Full-text available
In this work, we study a novel mobility prediction algorithm based on past long-term and short-term trajectories of users. In particular, we perceive the regularity of users' movements by training a Markov Renewal Process (MRP) using the long-term trajectory history. Moreover, short-term trajectory data, recorded within the current residing cell, i...
Article
In this work we show a novel algorithm for strong Line-of-Sight (LoS) Multiple-Input-Multiple-Output (MIMO) channel equalization. With optimally spaced antennas under specific arrangements, the LoS channels can be made spatially orthogonal. In practice, antenna displacements are expected. Conventional algorithms like zero-forcing do not consider th...
Conference Paper
Millimeter wave (mmwave) bands offer enormous untapped spectrum for broadband radio communications. For high dimensional and sparse multiple input multiple output (MIMO) channels, analog beamforming (ABF) and digital multi-stream beamforming (DBF), collectively known as hybrid beamforming (HBF), enable low cost and low power-consumption radio archi...
Article
With large bandwidths, millimeter wave (mmWave) line-of-sight (LoS) multi-input multi-output (MIMO) technology employing parallel stream transmission is well suited for future wireless backhaul systems. However, hardware imperfections of mmWave transceivers cause additional signal processing challenges. Considering the channel and hardware properti...
Article
Full-text available
Measurement results for millimeter wave LOS MIMO systems are presented with a focus on time variation and multipath propagation. Different system setups are used, including 2x2 and 3x3 MIMO, and involving different synchronization procedures and front-ends. Furthermore, different propagation scenarios are evaluated, covering a wide area of applicat...
Chapter
This chapter focuses on the description of transport network architecture suitable for 5G in terms of both user plane (UP) and control plane (CP). The 5G UP architecture considers converged optical and wireless network domains in a common 5G infrastructure supporting both transport and access. Given the great degree of technology heterogeneity in t...
Conference Paper
In this paper an approach for implementation of a time of flight ranging methods on a software defined radio (SDR) platform is presented. The proposed approach is intended to be implemented in software running on a host computer without changing the existing hardware of the SDR platform. This approach can be easily extended for use in positioning m...
Article
This article presents a converged 5G network infrastructure and an overarching architecture to jointly support operational network and end-user services, proposed by the EU 5G PPP project 5G-XHaul. The 5G-XHaul infrastructure adopts a common fronthaul/backhaul network solution, deploying a wealth of wireless technologies and a hybrid active/passive...
Conference Paper
The dawn of 5G requires significantly higher data rates, not only for the Radio Access Technology (RAT), but also for the transport network. Line-of-Sight MIMO links based on mmWave radios promise reaching ultra-high throughput with reasonably small antennas. mmWave links with optimally arranged antennas are one viable concept for spatial multiplex...
Article
Full-text available
To meet the requirements of 5G mobile networks, several radio access technologies, such as millimeter wave communications and massive MIMO, are being proposed. In addition, cloud radio access network (C-RAN) architectures are considered instrumental to fully exploit the capabilities of future 5G RANs. However, RAN centralization imposes stringent r...
Conference Paper
In this paper we present measurement results for pure line-of-sight MIMO links operating in the millimeter wave range. We show that the estimated condition numbers and capacities of the measured channels are in good agreement with the theory for various transmission distances and antenna setups. Furthermore, the results show that orthogonal channel...
Article
The evolution to ultra-dense next generation networks requires a massive increase in throughput and deployment flexibility. Therefore, novel wireless backhaul solutions that can support these demands are needed. In this work we present an approach for a millimeter wave line-of-sight MIMO backhaul design, targeting transmission rates in the order of...
Article
The common European Information and Communications Technology sector vision for 5G is that it should leverage on the strengths of both optical and wireless technologies. In the 5G context, a wide spectra of radio access technologies-such as millimetre wave transmission, massive multiple-input multiple-output and new waveforms-demand for high capaci...
Conference Paper
With the evolution of the mobile networks towards more dense and flexible configurations, novel wireless backhaul solutions that can match the high capacity and flexibility demands are required in addition to the fixed fiber optics solutions. In this work we analyze the core backhaul requirements and the related system design challenges for utilizi...
Article
An in-depth treatment of impulse an radio ultra-wideband (IR-UWB) wireless system is provided reviewing theoretical background, proceeding with detailed implementation procedure, and finally giving simulation and test results. This is the first research and prototyping work to be published in the field of IR-UWB that operates in the 6–8 GHz band. T...