Hendrik C. Ferreira

Power line communications : theory and applications for narrowband and broadband communications over power lines

List of Contributors. Preface. List of Acronyms. 1 Introduction (The Editors). References. 2 Channel Characterization (P. Amirshahi, F. Canete, K. Dostert, S. Galli, M. Katayama and M. Kavehrad). 2.1 Introduction. 2.2 Channel Modeling Fundamentals. 2.3 Models for Outdoor Channels: LV Case. 2.4 Models for Outdoor Channels: MV Case. 2.5 Models for Indoor Channels. 2.6 Noise and Disturbances. 2.7 MeasuringTechniques. 2.8 PLC Channel EmulationTools. 2.9 Reference Channels for Access Domain. 3 Electromagnetic Compatibility (H. Hirsch and M. Koch). 3.1 Introduction. 3.2 Parameters for EMC Considerations. 3.3 Electromagnetic Emission. 3.4 Electromagnetic Susceptibility. 3.5 EMC Coordination. 3.6 EMC Regulationin Europe. 3.7 Final Remarks. 4 Coupling (P. A. Janse van Rensburg). 4.1 Introduction. 4.2 Filtering Basics. 4.3 Transformer-Capacitor Coupler Design. 4.4 Impedance Adaptation Concepts. 4.5 Experimental Verification. 4.6 Further Possibilities. 5 Digital Transmission Techniques (M. Ardakani, G. Colavolpe, K. Dostert, H. C. Ferreira, D. Fertonani, T. G. Swart, A. M. Tonello, D. Umehara and A. J. H. Vinck). 5.1 Introduction. 5.2 Modulation and Coding for Narrowband PLC Systems. 5.3 Modulation and Coding for Broadband PLC Systems. 5.4 Conclusion. 6 Protocols for PLC Systems (G. Bumiller, H. Hrasnica, L. Lampe, M. Lobashov and T. Stockhammer). 6.1 Introduction. 6.2 Broadband PLC Media Access Control Layer. 6.3 Protocols for PLC Supporting Energy Management Systems. 6.4 Internet Protocol Television Over PLC. 7 Industrial and International Standards on PLC-based Networking Technologies (Galli, M. Koch, H. A. Latchman, S. Lee and V. Oksman). 7.1 Introduction. 7.2 PLC Standardization by Industrial Alliances. 7.3 International Standards on PLC-Networking Technology. 7.4 ETSI and CENELEC Standards. 7.5 International EMC Product Standardization. 8 Systems and Implementations (I. Berganza Valmala, G. Bumiller, H. A. Latchman, M. V. Ribeiro, A. Sendin Escalona, E. R. Wade and L. W. Yonge). 8.1 Introduction. 8.2 PLC Smart Grid Systems. 8.3 PLC Broadband Access Systems. 8.4 Multimedia PLC Systems. 8.5 DC-PLC Systems. 8.6 PLC in Emerging Countries. 9 Conclusions (The Editors). Index.

Markov characterization of digital fading mobile VHF channels

We apply techniques for the modeling of error sequences on digital communication channels to results of experiments undertaken on mobile VHF channels. The experiments were carried out using four different modulation schemes at some of the different standardized signaling rates. The modulation schemes used were: FSK @ 300 baud, DPSK @ 1200 baud, QPSK @ 1200 baud, and 8-ary PSK @ 1600 baud, and in each case, subcarrier modulation was used. The experiments were undertaken for urban as well as freeway environments. Fritchman-partitioned Markov chain models were derived throughout, and from the models, block error probability distributions were derived. These block error probability distributions or P(m,n) give the probability that a block of n bits will contain exactly m errors. We present P(/spl ges/m,n) for 7-, 15-, 31-, 63-, 127-, and 255-b blocks, for the above-mentioned modulation schemes, in the mobile VHF environments mentioned. P(/spl ges/m,n) denotes the probability that at least m errors will occur in a block of n bits. Furthermore, the P(/spl ges/m,n) information presented here, should give some indication of the performance to be expected from block error-correcting schemes. >

Power line communications: an overview

We give a systems level overview of power line communications. Topics covered, include feasible applications of power line communications, and the impact of the currently evolving international standards on power line communications. The power line communications channel is discussed at some length. Existing communications systems and solutions are discussed. The results of some measurements on the channel, are presented.

Permutation trellis codes

We introduce the new concept of permutation trellis codes and present a generalized construction procedure, applying our technique of distance-preserving mappings. Minimum-distance decoding follows naturally, using the Viterbi algorithm. We furthermore investigate the performance of these codes when combined with multitone frequency-shift keying modulation and noncoherent detection in a diversity scheme, to make transmissions robust against narrowband, broadband, and background noise disturbances, such as those encountered in power-line communications.

Markov characterization of channels with soft decision outputs

It is shown that a methodology based on hidden Markov models is applicable to the modeling of slowly varying Rayleigh fading channels with additive Gaussian noise and soft decision outputs. The fading is considered to be frequency nonselective, and ideal demodulation is considered throughout. To prove the validity of robustness of the modeling technique, various results that show good agreement between the simulated channels and the models found are presented. Two soft decision statistical distributions, namely, the soft burst and soft burst interval distributions, are defined and compared. To illustrate the accuracy of the models obtained, the simulation and model outputs are compared for a convolutional encoder with Viterbi decoding and various degrees of interleaving. >

On multiple insertion/deletion correcting codes

We investigate binary, number-theoretic, bit insertion/deletion correcting codes as pioneered by Levenshtein (1965, 1966, 1989). The weight spectra and Hamming distance properties of single insertion/deletion error-correcting codes are analyzed. These relationships are then extended to investigate codes that can correct multiple random insertions and deletions. From these relationships, new bounds are derived and a general construction for multiple insertion/deletion correcting codes is proposed and evaluated.

Design of a bidirectional impedance-adapting transformer coupling circuit for low-voltage power-line communications

In this paper, the design of an impedance-adapting bidirectional transformer coupling circuit for low-voltage power-line communications is described. It is shown that transmission through the transformer is governed by series resonance of the leakage inductance and coupling capacitance. At low frequencies though, the magnetizing inductance plays an important role in filtering the power waveform. The coupling transformer, if properly designed, can equalize terminating impedances on either side for maximum power transfer. Furthermore, these equalized terminating impedances facilitate symmetrical bidirectional band-pass transmission.

Interference cancellation with permutation trellis codes

We describe a modulation/coding scheme combining M-FSK modulation with diversity and coding to make the transmission robust against permanent frequency disturbances and impulse noise. We use simple non-coherent detection. The scheme can be considered as a form of coded frequency hopping and is easy extendable. We give a generalized construction procedure for new trellis codes of various rates and constraint lengths using our previously published technique of distance preserving mapping. Maximum likelihood decoding of these codes can follow naturally.

Lower bounds on the minimum hamming distance achievable with runlengh constrained or DC free block codes and the synthesis of a (16,8) D min = 4 DC free block code

Error correction coding gain can be obtained with dc free magnetic recording codes having a minimum Hamming distance d_{\min}\geq 4 . In this information theoretic paper we establish lower bounds on the minimum Hamming distance achievable with (2n,k) (ie R = k/2n) block codes with runlength constrained or dc free sequences, and present a table with the computed guaranteed minimum values of k for (2n,k) dc free block codes with (b=0, l=2n-1, C=n) sequences, a specified block length 2n and desired minimum Hamming distance d_{\min} . Subsequently, we present the formal synthesis of a (16,8) d_{\min}=4 code with sequences which have, in NRZ notation, a minimum runlength of 1 and maximum runlength of 8, while the bound on the maximum instantaneous accumulated charge is C = 5. This accumulated charge returns to zero at the end of each 16 bit code word. Encoding and decoding schemes for the synthesized code are also proposed.

On the evaluation and application of Markov channel models in wireless communications

We parameterize and compare three different classes of discrete channel models (Gilbert (1960), Gilbert-Elliott (1963) and Fritchman (1967)) for Gaussian minimum shift keying, as used in the GSM cellular system, on a Rayleigh fading channel. The generation of the appropriate data for the derivation of the discrete channel models is done by means of a simulation. In the simulation we assume that the fading is slow enough such that the receiver may perform perfect carrier recovery and synchronization. After comparing the three models, one is chosen as representative of the effects encountered on the channel. Lastly, we find analytical expressions for the parameters of the model as a function of the average signal-to-noise ratio by means of a curve fit.