Characterization of Hybrid Communication Channel in Indoor Scenario

Abstract

This work focuses on the characterization of indoor hybrid power line communication (PLC)-wireless channels in the frequency band between 1.7 and 100 MHz. These hybrid channels allow the simultaneous exploitation of the ubiquitous PLC channel and the mobility benefits offered by the wireless signals radiating from and being induced into power cables. A comprehensive study and analysis was conducted based on: (i) coherence time, (ii) additive noise power spectral density, (iii) coherence bandwidth, (iv) delay spread, (v) average channel gain, (vi) channel frequency response and (vii) channel capacity. Based on the reported analysis, the magnitude responses of hybrid PLC-wireless channels can be assumed to be symmetrical and significantly frequency selective. Also, we reveal that additive noise power spectral density and, consequently, channel capacity differ considerably in the PLC-to-wireless and wireless-to-PLC transmission directions. Finally, we show that the measured PLCwireless channels present a channel capacity of up to hundreds mega bits per second.

Statistical analysis and modeling of a novel parameter for resource allocation in multicarrier PLC systems

“…The measurement campaign of hybrid PLC‐wireless channels was conducted together with the one of in‐home PLC channels, shortly described in Section 4.1. Because of its uniqueness, the following data transmission directions must be considered when working with PLC‐wireless channels : the first one is the PLC‐to‐wireless direction, in which the transmitted signal is injected into the electric power grid and part of the energy of this signal is irradiated and captured by an antenna; the second one is the wireless‐to‐PLC direction, in which the transmitted signal is injected into the air by an antenna and part of this signal is induced in the power line and captured by a PLC modem.…”

“…It is important to emphasize that the channel impulse response estimates of such channels are almost the same, regardless of the data transmission direction. However, the same is not valid for the additive noise measurements, which results in rather different nSNR values in both directions, see Oliveira et al for more details.…”

“…If the data transmission occurs in the wireless‐to‐PLC direction, then there are disparate results, since the additive noise from PLC channels is completely different from the one in wireless channels . The evaluation criteria for the best models with single‐component and Gaussian mixture distributions for the nSNR coherence bandwidth are listed in Table , while these models are shown in Figure .…”

“…In this context, we focus on a comprehensive disscussion on the so‐called nSNR coherence bandwidth, which can be a very interesting parameter to reduce computational complexity of resource allocation techniques applied to OFDM‐based PLC systems. Due to its characteristics, the nSNR coherence bandwidth is capable of precisely characterizing the flatness of the nSNR and therefore is more suitable than the coherence bandwidth for determining the chunk length/bandwidth in resource allocation techniques, such as in Colen et al and Colen et al Moreover, considering a data set constituted by PLC channel estimates and additive noises measurements of in‐home, low‐voltage outdoor, and hybrid PLC‐wireless environments, we statistically model the nSNR coherence bandwidth. Such modeling is useful to conduct a performance analysis of the influence of chunk length/bandwidth on resource allocation techniques applied to OFDM‐based PLC systems.…”

PLC Systems Under the Presence of a Malicious Wireless Communication Device: Physical Layer Security Analyses

“…Also, discussion of numerical results related to secrecy outage probability and ergodic achievable secrecy rate considering a passive eavesdropper (i.e., the channel state information (CSI) of Eve is not available at Alice). Numerical results make use of a real data set obtained from the measurement campaign carried out in Brazilian in-home facilities [15], [16]. • Performance analysis considering the following issues: distinct distances between Alice and Bob; different positions of Eve in relation to Alice and Bob; distinct levels of the total transmission power (e.g., practical and theoretical); and two types of resource allocation technique (optimal and uniform).…”