The multiple-input multiple-output (MIMO) technique is well known in the field of wireless communications, and has recently been proposed to increase the capacity of in-home power line communication (PLC) networks. MIMO PLC employs the protective earth in addition to the classical line and neutral wires to form a multi-sensor transmission channel. By considering the additional reception of common-mode signals, up to two simultaneous transmit ports and four receive ports can be considered. In order to develop new signal processing strategies optimally exploiting the MIMO propagation characteristics and to evaluate their performance, the accurate modeling of the transmission channel is necessary. This paper presents a comprehensive statistical model of the in-home MIMO PLC channel based on an extensive measurement data base collected in six European countries. The paper first analyzes the main MIMO PLC channel parameters, including path loss parameters and wideband parameters, such as the delay spread, coherence bandwidth, and small-scale statistics. A focus is then made on the MIMO correlation matrix, and its modeling using empirical statistical distributions. A fully parameterized channel model is then developed, with a particular emphasis on both the frequency fading structure of the transfer function and the correlation matrix between sub-channels. As a result, the proposed model generates random MIMO PLC channel realizations, statistically representative of the experimental observations.

In this paper a simulations-based evaluation of the energy efficiency performance of relay Power Line Communication (PLC) networks is reported. Our system model is based on two PLC modems as source/destination and one relay modem with time division Decode-and-Forward (DF) scheme. In addition to the transmission power, we consider the static power of PLC modems in our energy consumption model and find the best energy efficiency performance for DF strategy by optimizing the transmission time of each link. Through extensive numerical results and two representative scenarios, we show that the use of PLC relaying with optimal time allocation allows for better performance than direct transmission, yet achieving the same rate of the direct transmission.

This paper presents a detailed measurement study of the electrical energy consumption of commercial Multiple Input Multiple Output (MIMO) Power Line Communications (PLC) modems. Based on these measurements, we propose a linear model that can be used to predict the energy consumed for different communication states and different operation modes of MIMO PLC modems (idle, standby, transmission, reception, variable data rates and variable Ethernet frame sizes). A multiple regression analysis is used to estimate the model parameters. Such an experimental campaign provides valuable data for benchmarking the energy consumption of MIMO PLC modems and gives insights on which energy improvements can be evaluated.

Within the ICT OMEGA project, a thorough study of the Electro Magnetic Compatibility (EMC) issues linked to Power Line Communications (PLC) has been conducted. In this paper, we present our investigations carried out in the context of a frequency bandwidth extension of PLC systems up to 100 MHz. The current status of EMC regulations for PLC is first recalled. An experimental study is then presented for the assessment of the effect of electromagnetic field radiation from an electrical network, in the 30 - 100 MHz band. Recommendations are given for the injected PSD levels to be used for future studies within the OMEGA project. From these results, the capacity of the PLC channel is evaluated in terms of outage probability. This analysis shows that an extended bandwidth up to 100 MHz provides capacities in excess of 1 Gbps, while satisfying the current emission limits. Finally, the possible countermeasures for the mitigation of EMC issues are discussed.

This paper describes a pragmatic approach on the up-conversion of WiMedia compliant UWB signals into the 60 GHz band. This dual band concept is based on propagation measurements at {3.1-10.6} and 60 GHz. Due to stringent frequency regulation, UWB systems operating in the 3.1 to 10.6 GHz bands are both bandwidth limited and power limited. Therefore, many potential users hesitate to deploy this technology. Up-conversion to the 60 GHz band and enhanced baseband parameters can make UWB technology more reliable and hence, more attractive. An experimental system based on a commercially available UWB development kit and IHPpsilas 60 GHz chip-set has been developed. The system architecture is described. Measurement results indicate that this combination may be interesting for many applications.

Millimeter wave wireless communications are opening the way towards high data rate applications for WPAN scenarios. Multi-Gbps wireless systems are currently defined by standardization bodies. This paper presents a complete 60 GHz OFDM PHY layer proposal fulfilling the requirements of the IEEE 802.15 Task Group 3c. Data rates are ranging from 335 Mbps to 3 Gbps, with a high level of scalability. The proposed system is designed to operate in the 57 to 66 GHz frequency band, with a possibility to use channel sizes of 1 GHz and 2 GHz. The OFDM PHY layer allows scalable spectrum efficiency to achieve high data rates with flexible radio coverage. For a nominal channel bandwidth of 1 GHz, the system uses an FFT size of 1024, convolutional coding and advanced interleaving schemes. Simulation results show that this system is well suited for very high data rate applications in realistic scenarios.

Time reversal is a promising technique for the improvement of future telecommunication systems. It may increase throughput while reducing receiver complexity. A better understanding of this capability requires more investigation on measured channels. This study used circular array propagation measurements. These measurements are efficient to estimate space-time focusing characteristics simultaneously. Because the delay spread parameter is inappropriate, a new parameter is introduced to study time focusing. Focusing parameters of two time reversal schemes are investigated. Time reversal improves the data rate by a factor of three and increases the received power using the entire FCC bandwidth. The one-bit time reversal scheme improves space focusing but provides smaller gain on other focusing parameters. The trend is the same with smaller bandwidth, but the benefits are reduced. The optimal bandwidth should be close to 3 GHz.

In order to design communication systems fully exploiting the FCC-defined ultra wideband (UWB) spectrum, an accurate knowledge of the propagation mechanisms is necessary. This paper presents a comprehensive UWB channel measurement campaign designed in the office indoor environment to cover the 3.1 GHz - 10.6 GHz frequency band. From an extensive set of recorded channel impulse responses (CIRs), statistical analyses permitted to extract the main UWB radio channel characteristics, such as the UWB path loss, delay spread and cluster and ray arrival rates. In particular, an alternative to the classical Saleh and Valenzuela approach is proposed for the description of UWB power delay profiles (PDPs). Our experimental set of collected parameters may be used to build a realistic model for the UWB radio channel

Comprehensive modelling of the ultra-wide band (UWB) radio channel necessitates a good knowledge of its fading statistics. To evaluate the fluctuations of the UWB channel, a propagation experiment has been conducted in the 3.1 - 11 GHz frequency band, involving different antenna locations and moving people. The presented results emphasize the difference between the spatial and temporal channel variability, and provide a practical assessment of the UWB signal fading distribution in the case of a dynamic environment.