Channel Coding and Receiver Design for Simultaneous Wireline Information and Power Transfer

Abstract

For the first time, the recently proposed "talkative power" paradigm combining power electronics and communication engineering is extended by channel coding and advanced receiver design aspects. In this concept, the pulses that control the duty cycle of switched-mode power converters are simultaneously used for data transmission by modifying the pulse phase, pulse frequency, pulse position or pulse width. The data sequence is embedded into the switching signal, similar to random modulation. The data can be used for example in point-to-point links, inside multi-port power converters, and for communication in networked power grids. As an application example a buck converter is studied. Its output voltage is numerically calculated for arbitrary two-level switching signals. The corresponding system model serves as a common framework for switching waveform design, receiver design, and performance analysis. The data sequence is represented by a small deterministic output voltage ripple. Various techniques to improve the data rate and the robustness of the communication are introduced, including line coding, a derivation of the optimum receiver in the sense of maximum-likelihood detection, and forward error correction coding as an option. Although emphasis is on a buck converter, the concept is applicable to other power converter topologies as well.

Overview of Talkative Power Conversion Technologies

“…This finding can be further extended without violating the grid codes and standard requirements for Total Harmonic Distortion (THD) criteria. COM can be integrated into the PE converter software providing simultaneous information and energy transfer which is called talkative power [8], [18]. The TP concept is represented in Fig.…”

“…The SNR is defined as the ratio of signal power to noise power [18]. The SNR must exceed a certain threshold value in order to guarantee an acceptable bit error rate.…”

“…Because the ripple should be as small as possible from a power quality point of view, a trade-off between PE constraints and COM requirements exists. Channel coding is a suitable technique for reducing signal power while still achieving an acceptable bit error rate [18].…”

“…PWM techniques suitable for TPC include PWM-FSK, PWM-PSK, PWM-PPM, and PWM-Frequency Hopping-Differential PSK (PWM-FH-DPSK) [17], [18]. Besides, PWM Spread Spectrum (PWM-SS) communication was also proposed to increase the resistance against interference [19].…”

Zero-Additional-Hardware Power Line Communication for DC–DC Converters

“…However, several filters are required at the receiver side, which represent additional system complexity. Recently, [10] presented an analysis of different data coding methods to improve the communication bit rate and reliability. In most cases, the Discrete Fourier transform (DFT) is used in the demodulation procedure which is likely to represent a high computational load compared to standard PID controllers used for the control of power electronics, especially if it must be executed at a high sampling frequency.…”