Cooperative Relaying In Power Line Environment: A Survey and Tutorial

Exchange of information is essential in any society and the demand for faster, cheaper, and secure communications is increasing every day. With other hi-tech initiatives like IPv6 and Internet-of-Things (IOT) already in the horizon, demand for broadband is set to escalate beyond its current level. Inherently laden in the challenges posed by this technology are fresh opportunities in terms of penetration of data services into rural communities and development of innovative strategies for more efficient use of the grid. Though still in its developmental phase/stage, Power Line Communication (PLC) has grown beyond theoretical fantasy to become a reality. The proofs are the readily available PLC systems that can be purchased off the shelfto achieve in-house networking and the much talked about, smart metering technology; generally regarded as the “new bride” in utilities industry. One of the biggest gains of PLC is its use of existing electrical cables, thereby eliminating cost of installation and maintenance of data cables. However, given that the power infrastructure was traditionally built to deliver electricity, data signals do suffer various forms of distortions and impairments as they transit it. This paper presents a tutorial on the deployed wireless system technique which is to be adapted to PLC scenario for the purpose of managing the available source energy for achieving reliable communication system. One of these techniques is the cooperative diversity. Its application and deployment in power line environment is explored. The improvement achieved through cooperative diversity in some PLC systems were presented along with the associated limitations. Finally, future areas of research which will further improve the reliability of PLC systems and reduce its power consumption during transmission is shown

Power Line Communication (PLC) Impulsive Noise Mitigation: A Review

Power Line Communication (PLC) is a technology which transforms the power line into pathways for the conveyance of broadband data. It has the advantage for it can avoid new installation since the current installation used for electrical power can also be used for data transmission. However, this power line channel presents a harsh environment for data transmission owing to the challenges of impulsive noise, high attenuation, selective fading and etc. Impulsive noise poses a severe challenge as its Power Spectral Density (PSD) is between 10–15dB above background noise. For good performance of the PLC system, this noise must be mitigated.  This paper presents a review of the techniques for the mitigation of impulsive noise in PLC which is classified into four categories, namely time domain, time/frequency domain, error correction code and other techniques. Time domain technique is a memoryless nonlinear technique where the signal's amplitude only changes according to a specified threshold without changing the phase.  Mitigation of impulsive noise is carried out on the received time domain signal before the demodulation FFT operation of the OFDM. Time/Frequency technique is a method of mitigating impulsive noise on the received signal at both before FFT demodulation and after FFT demodulation of the OFDM system. Error correction code technique is the application of forward error correction code by adding redundancy bits to the useful data bits for detection and possibly correction of error occurring during transmission.  Identifying the best performing technique will enhance the deployment of the technique while exploring the PLC channel capacity enhancement in the future. The best performing scheme in each of the category were selected and their BER vs SNR curves were compared with respect to the impulsive noise + awgn curve. Amongst all of these techniques, the error correction code technique had a performance that presents almost an outright elimination of impulsive noise in power line channel. Keywords: Impulsive noise, time domain, time/frequency domain, error correction code, sparse Bayesian learning, recursive detection and modified PLC-DMT

Selective relaying for reliability in power line cooperative communication system

Power line communication (PLC), a technology that uses the existing infrastructure for electric power for the provision of data, is fast becoming the choice for smart grid system. As good a choice as the PLC is for smart grid applications, it has some characteristics that poses hazards to signal transmitted through it. The topology of the power network (star) poses challenges of attenuation and multipath to high-speed signal transmission. The noise in PLC is not only AWGN as in other communication system but also impulsive. In this paper, selective relaying is considered for improving the reliability of the power line cooperative communication system. Selective relaying was implemented in both amplify-And-forward and decode and forward links on the PLC. Best channel SNR was the selection criterion for the best relay. Performances of symbol error rate and channel capacity was compared for fixed and selective relaying cooperation on the PLC system. Over a specified SNR range, the selective amplify-And-forward achieved a 6% SER improvement over the fixed relaying, while 1% SER improvement was achieved by the selective relaying over the fixed relaying on the decode-And-forward link. The channel capacity performance comparison reveals that the selective relaying in all scenarios in PLC achieved appreciable improvement on both cooperative protocols than in the fixed relaying

Power Line Communication (PLC) impulsive noise mitigation: a review

Power Line Communication (PLC) is a technology which transforms the power line into pathways for the conveyance of broadband data. It has the advantage for it can avoid new installation since the current installation used for electrical power can also be used for data transmission. However, this power line channel presents a harsh environment for data transmission owing to the challenges of impulsive noise, high attenuation, selective fading and etc. Impulsive noise poses a severe challenge as its Power Spectral Density (PSD) is between 10–15dB above background noise. For good performance of the PLC system, this noise must be mitigated. This paper presents a review of the techniques for the mitigation of impulsive noise in PLC which is classified into four categories, namely time domain, time/frequency domain, error correction code and other techniques. Time domain technique is a memoryless nonlinear technique where the signal's amplitude only changes according to a specified threshold without changing the phase. Mitigation of impulsive noise is carried out on the received time domain signal before the demodulation FFT operation of the OFDM. Time/Frequency technique is a method of mitigating impulsive noise on the received signal at both before FFT demodulation and after FFT demodulation of the OFDM system. Error correction code technique is the application of forward error correction code by adding redundancy bits to the useful data bits for detection and possibly correction of error occurring during transmission. Identifying the best performing technique will enhance the deployment of the technique while exploring the PLC channel capacity enhancement in the future. The best performing scheme in each of the category were selected and their BER vs SNR curves were compared with respect to the impulsive noise + awgn curve. Amongst all of these techniques, the error correction code technique had a performance that presents almost an outright elimination of impulsive noise in power line channel