Khmaies Ouahada

Low-complexity SOCPBFSK-OOK interface between PLC and VLC channels for low data rate transmission applications

This paper studies and proposes a low cost low complexity interface between power line communications (PLC) and visible light communications (VLC) for low data rate transmission applications. The discussion presents the performance of a spread orthogonal continuous phase binary frequency shift keying (SOCPBFSK) receiver combined with an on-off keying (OOK) modulator to relay low data transmission between PLC and VLC channels. The characteristics of the interface are presented. The results of an experimental test using the proposed interface over the European Committee for Electrotechnical Standardization (CENELEC) bands C and D are presented. The eye diagrams of the combined error are presented as well.

Renewable Energy Sources microgrid design for rural area in South Africa

Approximately 1.4 billion people around the world lack access to electricity, of which 85% are rural dwellers, mostly living in Sub-Saharan Africa. In South Africa, 55% of rural dwellers lack access to electricity. The Umhlabuyalingana Local Municipality is the least electrified municipality in the country with an electrification rate of 20%. It is therefore taken as a case study, investigating the implementation of a Renewable Energy Sources (RES) microgrid compared to grid extension. HOMER software was the tool used to carry out the simulation, optimization and sensitivity analyses in this research. It was discovered that a Photo Voltaic (PV) with Battery system is the optimal microgrid combination for the proposed microgrid yielding

Moment Balancing Templates: Constructions to Add Insertion/Deletion Correction Capability to Error Correcting or Constrained Codes

0.378/kWh cost of electricity, 0 kg/person CO2 emission, 100% renewable penetration compared to

Nonbinary convolutional codes and modified M-FSK detectors for power-line communications channel

0.328/kWh cost of grid electricity, 8.9 kg/person CO2 emission from grid extension and 0% renewable penetration from the national grid. The microgrid had a standalone breakeven Electric Distance Limit of 34 km less than the 150 km transmission powerline required for uMhlabuyalingana. This microgrid design is proposed as a better solution to electricity access in unelectrified areas of Umhlabuyalingana local municipality than grid extension.

Combined Higher Order Spectral Nulls Codes and OFDM Modulation for Power Line Communications

Templates are constructed to extend arbitrary additive error correcting or constrained codes, i.e., additional redundant bits are added in selected positions to balance the moment of the codeword. The original codes may have error correcting capabilities or constrained output symbols as predetermined by the usual communication system considerations, which are retained after extending the code. Using some number theoretic constructions in the literature, insertion/deletion correction can then be achieved. If the template is carefully designed, the number of additional redundant bits for the insertion/deletion correction can be kept small-in some cases of the same order as the number of parity bits in a Hamming code of comparable length.

Experimental evaluation of NFC reliability between an RFID tag and a smartphone

The Viterbi decoding algorithm, which provides maximum ¿ likelihood decoding, is currently considered the most widely used technique for the decoding of codes having a state description, including the class of linear error-correcting convolutional codes. Two classes of nonbinary convolutional codes are presented. Distance preserving mapping convolutional codes and M-ary convolutional codes are designed, respectively, from the distance-preserving mappings technique and the implementation of the conventional convolutional codes in Galois fields of order higher than two. We also investigated the performance of these codes when combined with a multiple frequency-shift keying (M-FSK) modulation scheme to correct narrowband interference (NBI) in powerline communications channel. The modification of certain detectors of the M-FSK demodulator to refine the selection and the detection at the decoder is also presented. M-FSK detectors used in our simulations are discussed, and their chosen values are justified. Interesting and promising obtained results have shown a very strong link between the designed codes and the selected detector for M-FSK modulation. An important improvement in gain for certain values of the modified detectors was also observed. The paper also shows that the newly designed codes outperform the conventional convolutional codes in a NBI environment.

Using Graphs for the Analysis and Construction of Permutation Distance-Preserving Mappings

We present different techniques for designing codes with higher order spectral nulls, based on the power spectral density function; the binary representation of permutation codes and the finite state machine representation. Distance increasing mappings (a technique for mapping convolutional code outputs onto constrained symbols) is applied to generate codes with a certain power spectral density function and enhanced error correction capabilities. Combining this class of new codes with an OFDM modulation scheme is a very strong candidate-coding scheme for non-AWGN channels such as the power line communications channel

Combined Non-Binary Codes and M-FSK Modulation for Power Line Communications

Near Field Communication (NFC) is a short range wireless technology that enables data transfer between two NFC devices. It is derived from Radio Frequency Identification (RFID) technology. However, NFC only operates at 13.56MHz frequency while RFID operates at both 125KHz and 13.56MHz frequencies. The success of NFC in replacing contact cards in payment systems can be duplicated in other industries. It is very critical that the operation of NFC is well understood so that future applications can make life easier for the users. The main purpose of this paper is to find out the parameters that can affect the optimal operation of passive NFC devices.

Viterbi decoding of ternary line codes

A new way of looking at permutation distance-preserving mappings (DPMs) is presented by making use of a graph representation. The properties necessary to make such a graph distance-preserving, are also investigated. Further, this new knowledge is used to analyze previous constructions, as well as to construct a new general mapping algorithm for a previous multilevel construction.

Wireless sensor networks and advanced metering infrastructure deployment in smart grid

Three different types of non-binary error correction codes and an M-FSK modulation scheme were combined to correct narrowband interference in power line communications. Specifically, non-binary convolutional codes, permutation trellis codes and Reed-Solomon codes were combined with the M-FSK modulation scheme. We present in this paper results on these different coding techniques when used to correct narrowband noise