5 research outputs found

    Adaptive permutation coded differential OFDM system for power line communications

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    Abstract: With a view to improving the capacity of the differential OFDM modulation scheme, specified in the narrowband power line communications (PLC) standards, in combating PLC channel associated noise, we hereby propose a permutation coded modulation scheme, which employs the hybridization of two kinds of DPSK (differential phase shift keying) modulations in an adaptive manner. The algorithm for deducing the encoded information from the hybridized modulations is described as well. This scheme is simulated and its performance is compared with a recently reported differential quinary PSK-OFDM system in the literature, whose behaviour has been shown to be better than the conventional permutation coded D8PSK-OFDM scheme at lower signal power to noise spectral density. Due to the simplicity in its encoding and decoding algorithms, this scheme is a good candidate for a number of low speed telemetry signaling in smart grids

    A semi-hidden Markov modeling of a low complexity FSK-OOK in-House PLC and VLC integration

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    Abstract: The integration of power line communication (PLC) and visible light communication (VLC) is increasingly receiving a lot of research interest with the advent of (IEEE 1901, ITUT G.9960/61) and IEEE 802.15.7 standards for PLC and VLC respectively. In particular, there is an underlying gain that could be achieved by leveraging the existing ubiquitous power line network infrastructure to render connectivity, while we also exploit the illumination system of power-saving Light Emitting Diodes (LEDs) for wireless data communication. The ubiquitous nature of these two systems makes us belief that VLC can offer a good complementary wireless data transmission technology to the existing In-House PLC in a similar manner broad-band Ethernet connections enjoys the support of Wi-Fi. This paper thus reports an implementation of a low complexity FSK-OOK In-House PLC and VLC Integration, as well as it’s Second-Order Semi-Markov Model. The resulting statistical models facilitates the design and evaluation of forward error correcting codes to mitigate burst error occurrences, as well as optimizing the performance of the overall system

    Narrowband PLC channel modeling using USRP and PSK modulations

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    The indoor narrowband power line communication (NB-PLC) suffers from noise impairments, which emanate from several end-user electrical devices connected across the PLC channel. These noise impairments result into burst errors, which consequently lead to data corruption. Therefore, in order to implement robust communication techniques that will thrive on the noisy PLC channel, a full knowledge and modeling of the noise that exists on the NB-PLC channel is inevitable. This paper thus reports a First-order Markov modeling of NB-PLC channel noise, based on experimental measurements. For the modeling, BPSK, DBPSK, QPSK and DQPSK modulation schemes were implemented using Universal Software Radio Peripheral (USRP). The resulting channel models are useful for improving the robustness of the above modulation schemes as well as designing forward error correction techniques for mitigating the effect of noise impairments. The results are also useful in optimizing NB-PLC system design, thereby, enhancing the accuracy and improving the overall PLC system performance

    Evaluation and implementation of cyclic permutation coding for power line communications

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    Abstract: Noise and attenuation, in the form of frequency disturbance, impulsive noise, additive white Gaussian noise (AWGN) and frequency selective fading, are the major setbacks in power line communications (PLC). In order to effectively combat this challenge, we thus report the development and implementation of a specially coded M-ary differential phase shift keying modulation scheme on narrowband PLC channel. The coding aspect involves the concatenation of conventional Reed Solomon (RS) code with cyclic permutation coding (CPC), resulting in what is termed RS-CPC scheme. The CPC employed in this work maps the output bits of a binary RS code onto non-binary CPC symbols, in a cyclic manner, with a view to improving the distance between two different sets of mapped symbols. For implementation over 230 V AC power line, software defined radio hardware, called the universal software radio peripherals (USRPs), were used, together with narrowband coupling circuits, to couple the signal to and receive it from the power line. Both by simulation and implementation, our scheme outperforms the conventional Reed Solomon-convolutional coding (RS-CC) specified in the G3-PLC standard. An added advantage is that our scheme is easier to implement
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