Showing papers by "Johannes B. Huber published in 2017"

Bit-interleaved coded modulation for phase shift keying on the hypersphere

Abstract: We analyze the performance of Bit-Interleaved Coded Modulation (BICM) for MIMO systems employing Phase Shift Keying on the Hypersphere (PSKH), an extension of conventional PSK to higher dimensions. Because the quality of BICM relies on the bit-mapping between coded bits and signal points, PSKH constellations with superior distance properties and capacities might have poor power efficiency. In this paper, we analyze these losses in power efficiency and propose a new method to generate PSKH constellations, i.e., spherical codes, together with a BICM optimized bit-mapping. It turns out that for one bit per real dimension, individual QPSK per antenna is optimal, whereas for other constellation sizes notable gains can be achieved.

A power line communication topology module for ns-3 and DCE

Abstract: Protocol development for power line communications (PLC) relies heavily on testing and verification under various conditions. As it is very difficult to implement testbeds with large and flexible topologies, network simulation is usually the means of choice. It is of particular importance that the physical layer model is not only flexible and of limited complexity, but also provides a good degree of realism. Especially for PLC the topology has large impact. We introduce a new module for the simulation of PLC networks with network simulator 3 (ns-3) and Direct Code Execution (DCE) that is flexible and efficient but also offers accurate results. We present a detailed description of the module, its features and implementation. We provide a comparison with the output of the circuit simulator LTspice for verification.

π/2-shifted phase shift keying on the hypersphere: Transmitter and receiver algorithms

Abstract: We introduce π/2-shifted Phase Shift Keying on the Hypersphere (π/2-PSKH), a new modulation scheme for Multiple-Input Multiple-Output (mIMO) systems. π/2-PSKH is a multidimensional extension of shifted QAM which allows to use load-modulated MIMO transmitters with a highly efficient power amplifier with reduced backoff. We propose π/2-PSKH constellations and explain how a π/2-PSKH signal is generated. The signal point sequence for π/2-PSKH is time-varying and as such has an inherent code. For the receiver, three algorithms are introduced and numerical simulations are used to examine their performance. These algorithms are further modified in order to reduce their complexity. We discuss the effect of this complexity reduction and the trade-off between receiver complexity and performance. It is shown that due to its inherent code, π/2-PSKH shows excellent performance in terms of power efficiency even if used with conventional amplifiers.