Matthias Woltering

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In this paper we consider physical-layer network coding (PLNC) in OFDM-based two-way relaying systems. Practically, a key impairment for the application of PLNC is the carrier frequency offset (CFO) mismatch between the sources and the relay, which can not be compensated completely in the multiple-access (MA) phase. As this CFO mismatch results in(More)
Massive Machine Type Communication is seen as one major driver for the research of new physical layer technologies for future communication systems. To handle massive access, the main challenges are avoiding control signaling overhead, low complexity data processing per sensor, supporting of diverse but rather low data rates and a flexible and scalable(More)
In this paper, two-way relaying networks using physical layer network coding under practical constraints are considered. In the multiple access phase, both users transmit their messages simultaneously on the same resources. At the relay a superposition of both massages is received containing the influence of the channel as well as the impact of Carrier(More)
Using general waveforms has recently gained omnipresent attention for robustness in systems under practical constraints. In this paper, two way relaying networks using physical layer network coding utilizing a multicarrier scheme with Gaussian waveforms are analyzed. This combination is introduced to be more robust against the impact of carrier frequency(More)
This paper discusses retransmission approaches to improve the throughput performance of Hybrid-ARQ (HARQ) schemes in a point-to-point single user 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) uplink system. One goal of communication systems is to achieve a reliable transmission with a throughput performance as close as possible to(More)
Compressed Sensing Multi-User Detection is a recently developed physical layer method to decrease signaling in massive Machine communications by using means from the field of Compressed Sensing and sparse signal processing. Within this work we use the advances of recent research and present a non-coherent CS-MUD system concept basing on a combination of(More)
This paper discusses two approaches of reliabilitybased HARQ, adapting the packet size of a retransmission in a 3GPP Long Term Evolution (LTE) system. We focus on the adaptation of the retransmission size in terms of physical resources by using information 1) of the channel, namely the signal-to-noise ratio (SNR) or 2) reliability information from the(More)
MCSM is a recently proposed novel system concept to solve the massive access problem envisioned in future communication systems like 5G and industry 4.0 systems. This work focuses on the practical verification of the theoretical gains that MCSM provides using a Hardware-In-the-Loop (HIL) measurement setup. We present results in two different scenarios: (i)(More)
The performance of physical-layer network coding (PLNC) in two way relay channels (TWRCs) is significantly decreased by impairments like carrier frequency offsets or timing offsets. This mismatch cannot be completely compensated at the receiver side, even if the offsets are known. Multi-carrier systems with Gaussian waveforms for TWRC systems are more(More)
Layered space time (LST) equalization which employs successive interference cancellation (SIC) and frequency domain equalization (FDE) has been proven to be a promising structure for the receiver of single-carrier (SC) systems with MIMO (Multiple-input Multiple-output) schemes. In this paper, the performance of iterative LST in long term evolution (LTE)(More)