Time programmable smart devices for peak demand reduction of smart homes in a microgrid
- Longe, O. M., Rimer, S., Ouahada, K., Ferreira, Hendrik C.
- Authors: Longe, O. M. , Rimer, S. , Ouahada, K. , Ferreira, Hendrik C.
- Date: 2015
- Subjects: Time programmable smart devices , Smart homes , Peak demand , Microgrid
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/85579 , uj:19364 , Citation: Longe, O.M. et al. 2015. Time programmable smart devices for peak demand reduction of smart homes in a microgrid.
- Description: Abstract: Increasing electricity access through Microgrids for rural areas is often faced with the challenge of increased peak demand through increased electricity demand as more electronic devices will be acquired by the consumers and more small businesses will spring up in the community. If not taken care of, this leads to additional cost of incurring higher peaker plants to meet the peak demand, and the burden of the cost of peaker plants are consequentially transferred to the consumers. Since this load is generated by the consumers, it is most desirable to control the peak demand from the consumers’ side. Therefore, a method of Time Programmable Smart Devices (TPSD) with an efficient Electricity Use Plan (EUP) is proposed in this paper by introducing appliance working knowledge and improving load shifting technique of Demand Side Management for peak demand reduction in a rural Microgrid. This method yielded lower morning and evening peaks, a lower peak-to-peak difference than those available in literature, and a peak period shift from the traditional peak period to traditional off-peak period. These lead to financial savings, reduced cost of peaker plants and a safer environment from less greenhouse gases emissions.
- Full Text:
- Authors: Longe, O. M. , Rimer, S. , Ouahada, K. , Ferreira, Hendrik C.
- Date: 2015
- Subjects: Time programmable smart devices , Smart homes , Peak demand , Microgrid
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/85579 , uj:19364 , Citation: Longe, O.M. et al. 2015. Time programmable smart devices for peak demand reduction of smart homes in a microgrid.
- Description: Abstract: Increasing electricity access through Microgrids for rural areas is often faced with the challenge of increased peak demand through increased electricity demand as more electronic devices will be acquired by the consumers and more small businesses will spring up in the community. If not taken care of, this leads to additional cost of incurring higher peaker plants to meet the peak demand, and the burden of the cost of peaker plants are consequentially transferred to the consumers. Since this load is generated by the consumers, it is most desirable to control the peak demand from the consumers’ side. Therefore, a method of Time Programmable Smart Devices (TPSD) with an efficient Electricity Use Plan (EUP) is proposed in this paper by introducing appliance working knowledge and improving load shifting technique of Demand Side Management for peak demand reduction in a rural Microgrid. This method yielded lower morning and evening peaks, a lower peak-to-peak difference than those available in literature, and a peak period shift from the traditional peak period to traditional off-peak period. These lead to financial savings, reduced cost of peaker plants and a safer environment from less greenhouse gases emissions.
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Low-complexity SOCPBFSK-OOK interface between PLC and VLC channels for low data rate transmission applications
- Ndjiongue, A. R., Ferreira, Hendrik C., Ouahada, K., Han Vinck, A. J.
- Authors: Ndjiongue, A. R. , Ferreira, Hendrik C. , Ouahada, K. , Han Vinck, A. J.
- Date: 2014
- Subjects: Frequency shift keying , Power line communications , Visible light communications
- Type: Book
- Identifier: uj:4747 , http://hdl.handle.net/10210/11733
- Description: 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.
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- Authors: Ndjiongue, A. R. , Ferreira, Hendrik C. , Ouahada, K. , Han Vinck, A. J.
- Date: 2014
- Subjects: Frequency shift keying , Power line communications , Visible light communications
- Type: Book
- Identifier: uj:4747 , http://hdl.handle.net/10210/11733
- Description: 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.
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Combined spectral shaping codes and OFDM modulation for narrowband interference channels
- Ouahada, K., Ferreira, Hendrik C., Han Vinck, A. J., Snyders, A. J., Swart, Theo G.
- Authors: Ouahada, K. , Ferreira, Hendrik C. , Han Vinck, A. J. , Snyders, A. J. , Swart, Theo G.
- Date: 2008
- Subjects: Distance-preserving mappings , Spectral nulls codes , Spectral shaping codes , OFDM modulation , Narrowband interference
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/21215 , uj:16126 , Citation: Ouahada, K. et al. 2008. Combined spectral shaping codes and OFDM modulation for narrowband interference channels. SAIEE Africa Research Journal, 99(1):11-17.
- Description: Abstract: Distance Preserving Mappings is a relatively new technique finding its way to a wide use in the coding field. New codes mapping convolutional code outputs onto spectral nulls codewords have the purpose of generating a code with a certain spectrum specification and error correction capabilities, which can be exploited by the Viterbi decoder. Combining this class of new codes with an Orthogonal Frequency Division Multiplexing modulation scheme is actually a tool to reduce Electromagnetic Compatibility Interference in selected subbands or to cancel the narrowband interference potentially caused by, amongst others, high frequency radio transmissions. Taking into consideration the fact that a narrowband noise source is almost similar to a modulated orthogonal frequency division multiplexing carrier, and also the periodicity of the nulls in our spectrum, we are able to cancel the narrowband signal and its sideband interferences without using traditional techniques of cancellation, which is based on filtering. Shaping our spectrum at the transmitter is a technique, which can be exploited at the receiver to suppress any narrowband signal interference, which is regarded as noise. We will present in this paper the technique of cancellation and the coding gain that can be obtained when comparing to the uncoded data.
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- Authors: Ouahada, K. , Ferreira, Hendrik C. , Han Vinck, A. J. , Snyders, A. J. , Swart, Theo G.
- Date: 2008
- Subjects: Distance-preserving mappings , Spectral nulls codes , Spectral shaping codes , OFDM modulation , Narrowband interference
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/21215 , uj:16126 , Citation: Ouahada, K. et al. 2008. Combined spectral shaping codes and OFDM modulation for narrowband interference channels. SAIEE Africa Research Journal, 99(1):11-17.
- Description: Abstract: Distance Preserving Mappings is a relatively new technique finding its way to a wide use in the coding field. New codes mapping convolutional code outputs onto spectral nulls codewords have the purpose of generating a code with a certain spectrum specification and error correction capabilities, which can be exploited by the Viterbi decoder. Combining this class of new codes with an Orthogonal Frequency Division Multiplexing modulation scheme is actually a tool to reduce Electromagnetic Compatibility Interference in selected subbands or to cancel the narrowband interference potentially caused by, amongst others, high frequency radio transmissions. Taking into consideration the fact that a narrowband noise source is almost similar to a modulated orthogonal frequency division multiplexing carrier, and also the periodicity of the nulls in our spectrum, we are able to cancel the narrowband signal and its sideband interferences without using traditional techniques of cancellation, which is based on filtering. Shaping our spectrum at the transmitter is a technique, which can be exploited at the receiver to suppress any narrowband signal interference, which is regarded as noise. We will present in this paper the technique of cancellation and the coding gain that can be obtained when comparing to the uncoded data.
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Efficient electricity usage plan for demand side management in the smart grid
- Longe, O. M., Ouahada, K., Ferreira, Hendrik C., Rimer, S.
- Authors: Longe, O. M. , Ouahada, K. , Ferreira, Hendrik C. , Rimer, S.
- Date: 2017
- Subjects: DOK-EUP , Peak Demand Reduction (PDR) , Time Shiftable Smart Appliance (TSSA)
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/251667 , uj:26216 , Citation: Longe, O.M. et al. 2017. Efficient electricity usage plan for demand side management in the smart grid.
- Description: Abstract: High peak demand is often a challenge to the grid and could result into measures such as procurement of additional plants to meet the peak demand, higher tariffs for consumers, undesirable load shedding or even black-outs. However, these issues can be mitigated by introducing Demand Side Management (DSM) techniques for effective energy management of consumers’ peak demand. In this paper, an enhanced Device Operation Knowledge - Electricity Usage Plan (DOK-EUP) is proposed, which applies time independencies of selected smart home appliances for peak demand reduction based on their operation principles and for consumer’s benefit. The proposed DOK-EUP technique was tested with the surveyed demand profile of a Time-of-Use (TOU) consumer and results showed lower morning and evening peak demands, lower peak-to-peak difference, shift in peak period to traditional off-peak periods, financial savings for the consumers and utility provider, and a cleaner environment.
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- Authors: Longe, O. M. , Ouahada, K. , Ferreira, Hendrik C. , Rimer, S.
- Date: 2017
- Subjects: DOK-EUP , Peak Demand Reduction (PDR) , Time Shiftable Smart Appliance (TSSA)
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/251667 , uj:26216 , Citation: Longe, O.M. et al. 2017. Efficient electricity usage plan for demand side management in the smart grid.
- Description: Abstract: High peak demand is often a challenge to the grid and could result into measures such as procurement of additional plants to meet the peak demand, higher tariffs for consumers, undesirable load shedding or even black-outs. However, these issues can be mitigated by introducing Demand Side Management (DSM) techniques for effective energy management of consumers’ peak demand. In this paper, an enhanced Device Operation Knowledge - Electricity Usage Plan (DOK-EUP) is proposed, which applies time independencies of selected smart home appliances for peak demand reduction based on their operation principles and for consumer’s benefit. The proposed DOK-EUP technique was tested with the surveyed demand profile of a Time-of-Use (TOU) consumer and results showed lower morning and evening peak demands, lower peak-to-peak difference, shift in peak period to traditional off-peak periods, financial savings for the consumers and utility provider, and a cleaner environment.
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Analysis of the devolo’s 500 kHz G3-PLC access technology based on smart grid field trials
- Papilaya, V. N., Han Vinck, A. J., Ouahada, K., Mengi, A., Weinand, M., Koch, M., devolo, AG
- Authors: Papilaya, V. N. , Han Vinck, A. J. , Ouahada, K. , Mengi, A. , Weinand, M. , Koch, M. , devolo, AG
- Date: 2014
- Subjects: Smart grid field trials , G3-PLC access technology
- Type: Article
- Identifier: uj:4799 , http://hdl.handle.net/10210/12053
- Description: In the smart grid, the G3-PLC solution is in direct competition with other IP-based communications technologies such as GPRS or DSL. In this paper, we present the devolo’s 500 kHz G3-PLC access technology and it’s analysis based on smart grid field trials in Germany. The focus of the analysis in this paper is concentrated on the following parameters: The influencing factor of near and far transmission throughput, the influence of a repeater on the throughput, and the influence of different UDP packet size on the throughput.
- Full Text: false
- Authors: Papilaya, V. N. , Han Vinck, A. J. , Ouahada, K. , Mengi, A. , Weinand, M. , Koch, M. , devolo, AG
- Date: 2014
- Subjects: Smart grid field trials , G3-PLC access technology
- Type: Article
- Identifier: uj:4799 , http://hdl.handle.net/10210/12053
- Description: In the smart grid, the G3-PLC solution is in direct competition with other IP-based communications technologies such as GPRS or DSL. In this paper, we present the devolo’s 500 kHz G3-PLC access technology and it’s analysis based on smart grid field trials in Germany. The focus of the analysis in this paper is concentrated on the following parameters: The influencing factor of near and far transmission throughput, the influence of a repeater on the throughput, and the influence of different UDP packet size on the throughput.
- Full Text: false
Effective energy consumption scheduling in smart homes
- Longe, O. M., Ouahada, K., Rimer, S., Zhu, H., Ferreira, Hendrik C.
- Authors: Longe, O. M. , Ouahada, K. , Rimer, S. , Zhu, H. , Ferreira, Hendrik C.
- Date: 2015
- Subjects: Smart meters , Smart home appliances , Low-income households
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/85609 , uj:19368 , Citation: Longe, O.M. et al. 2015. Effective energy consumption scheduling in smart homes.
- Description: Abstract: Monthly expenditure on electricity by most households in South Africa take beyond acceptable percentage of their income. In order to keep the household energy expenditure below the energy poverty threshold, a daily electricity optimization problem is formulated using mixed integer linear programming (MILP) method. The energy optimization scheduling was carried out by a device called the Daily Maximum Energy Scheduling (DMES) device proposed to be incorporated into smart meters of households. The DMES algorithm was tested with household data set and was shown to be capable of ensuring that households spend less than 10% of their income on electricity bill monthly. This technique therefore, would be beneficial to consumers (for better financial savings and planning), utility (for effective energy and financial savings, and energy network planning) and cleaner environments as proposed for smart grid. Also, number of households in the nation living below the energy expenditure-based poverty threshold would increase.
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- Authors: Longe, O. M. , Ouahada, K. , Rimer, S. , Zhu, H. , Ferreira, Hendrik C.
- Date: 2015
- Subjects: Smart meters , Smart home appliances , Low-income households
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/85609 , uj:19368 , Citation: Longe, O.M. et al. 2015. Effective energy consumption scheduling in smart homes.
- Description: Abstract: Monthly expenditure on electricity by most households in South Africa take beyond acceptable percentage of their income. In order to keep the household energy expenditure below the energy poverty threshold, a daily electricity optimization problem is formulated using mixed integer linear programming (MILP) method. The energy optimization scheduling was carried out by a device called the Daily Maximum Energy Scheduling (DMES) device proposed to be incorporated into smart meters of households. The DMES algorithm was tested with household data set and was shown to be capable of ensuring that households spend less than 10% of their income on electricity bill monthly. This technique therefore, would be beneficial to consumers (for better financial savings and planning), utility (for effective energy and financial savings, and energy network planning) and cleaner environments as proposed for smart grid. Also, number of households in the nation living below the energy expenditure-based poverty threshold would increase.
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Energy management and trading in a smart microgrid
- Authors: Longe, O. M. , Ouahada, K.
- Date: 2018
- Subjects: Distributed Energy Generation (DEG) , Distributed Energy Storage (DES) , Demand Side Management (DSM)
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/282028 , uj:30383 , Citation: Longe, O. M. & Ouahada, K. 2018. Energy management and trading in a smart microgrid.
- Description: Abstract: Abstract—Distributed Energy Generation (DEG) and Distributed Energy Storage (DES) are finding increasing applications in Demand Side Management (DSM) due to their potentials for grid power system balance and arbitrage opportunities. A grid-connected smart microgrid comprising heterogeneous (active and passive) smart consumers and a largescale energy storage device is considered in this work. Energy management by each smart entity is carried out by the proposed Microgrid Energy Management – Distributed Optimisation Algorithm (MEM-DOA) installed within the network according to consumer type. Each smart consumer optimises its energy consumption, expenditure and trading for comfort and profit. The proposed model was observed to yield financial benefits, grid reliability and sustainability, reduced investment on peaker plants, reduced Peak-to-Average-Ratio (PAR) demand and associated environmental benefits.
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- Authors: Longe, O. M. , Ouahada, K.
- Date: 2018
- Subjects: Distributed Energy Generation (DEG) , Distributed Energy Storage (DES) , Demand Side Management (DSM)
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/282028 , uj:30383 , Citation: Longe, O. M. & Ouahada, K. 2018. Energy management and trading in a smart microgrid.
- Description: Abstract: Abstract—Distributed Energy Generation (DEG) and Distributed Energy Storage (DES) are finding increasing applications in Demand Side Management (DSM) due to their potentials for grid power system balance and arbitrage opportunities. A grid-connected smart microgrid comprising heterogeneous (active and passive) smart consumers and a largescale energy storage device is considered in this work. Energy management by each smart entity is carried out by the proposed Microgrid Energy Management – Distributed Optimisation Algorithm (MEM-DOA) installed within the network according to consumer type. Each smart consumer optimises its energy consumption, expenditure and trading for comfort and profit. The proposed model was observed to yield financial benefits, grid reliability and sustainability, reduced investment on peaker plants, reduced Peak-to-Average-Ratio (PAR) demand and associated environmental benefits.
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Detecting the zero-crossing message to achieve low bit transmission over H-bridge inverter
- Ndjiongue, A. R., Han Vinck, A. J., Ouahada, K., Ferreira, Hendrik C., Snyders, A. J.
- Authors: Ndjiongue, A. R. , Han Vinck, A. J. , Ouahada, K. , Ferreira, Hendrik C. , Snyders, A. J.
- Date: 2014
- Subjects: Power line communications , Pulse width modulation
- Type: Article
- Identifier: uj:4753 , http://hdl.handle.net/10210/11739
- Description: Home automation and smart grid development is motivated by many advantageous situations that include the demands on renewable energy and the advantages provided by power line communications technology (PLC). The integration of solar energy into conventional grid implies the control of different modules included in the system. Remote control seems to be the control mode by excellence, in which communication is the main point to focus on. The pulse width modulation (PWM) scheme used to control the inverter is also used to modulate the zero-crossing point of the output sine wave of the inverter, to transfer data. The zero-crossing modulation technique is proposed and basic elements to construct the model are proposed. Simulated constellations of the received signal are presented.
- Full Text:
- Authors: Ndjiongue, A. R. , Han Vinck, A. J. , Ouahada, K. , Ferreira, Hendrik C. , Snyders, A. J.
- Date: 2014
- Subjects: Power line communications , Pulse width modulation
- Type: Article
- Identifier: uj:4753 , http://hdl.handle.net/10210/11739
- Description: Home automation and smart grid development is motivated by many advantageous situations that include the demands on renewable energy and the advantages provided by power line communications technology (PLC). The integration of solar energy into conventional grid implies the control of different modules included in the system. Remote control seems to be the control mode by excellence, in which communication is the main point to focus on. The pulse width modulation (PWM) scheme used to control the inverter is also used to modulate the zero-crossing point of the output sine wave of the inverter, to transfer data. The zero-crossing modulation technique is proposed and basic elements to construct the model are proposed. Simulated constellations of the received signal are presented.
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Renewable energy sources microgrid design for rural area in South Africa
- Longe, O. M., Ouahada, K., Ferreira, Hendrik C., Chinnappen, S.
- Authors: Longe, O. M. , Ouahada, K. , Ferreira, Hendrik C. , Chinnappen, S.
- Date: 2014
- Subjects: Microgrids , Renewable energy sources , Umhlabuyalingana Local Municipality
- Type: Article
- Identifier: uj:4798 , http://hdl.handle.net/10210/12052
- Description: 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 $0.378/kWh cost of electricity, 0 kg/person CO2 emission, 100% renewable penetration compared to $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.
- Full Text: false
- Authors: Longe, O. M. , Ouahada, K. , Ferreira, Hendrik C. , Chinnappen, S.
- Date: 2014
- Subjects: Microgrids , Renewable energy sources , Umhlabuyalingana Local Municipality
- Type: Article
- Identifier: uj:4798 , http://hdl.handle.net/10210/12052
- Description: 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 $0.378/kWh cost of electricity, 0 kg/person CO2 emission, 100% renewable penetration compared to $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.
- Full Text: false
Evaluation of the SFSK-OOK integrated PLC-VLC system under the influence of sunlight
- Nlom, S. M., Ouahada, K., Ndjiongue, A. R., Ferreira, Hendrik C.
- Authors: Nlom, S. M. , Ouahada, K. , Ndjiongue, A. R. , Ferreira, Hendrik C.
- Date: 2017
- Subjects: Narrowband PLC , VLC , S-FSK , PLC-VLC
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/237873 , uj:24379 , Citation: Nlom, S.M. 2017. Evaluation of the SFSK-OOK integrated PLC-VLC system under the influence of sunlight.
- Description: Abstract: With the widespread of light emitting diodes (LEDs) as a primary source of illumination, visible light communication (VLC) offers a lot of potentials by providing both resources and energy saving advantages. This paper presents a practical implementation of an integration of Power Line Communication (PLC) and VLC. The system uses spread frequency shift keying (S-FSK) and on-off keying (OOK) in the PLC and VLC channel respectively. The system is of low complexity, low cost and dedicated to enhance low data rate application of PLC technology. The practical design is compatible with the European Committee for Electrotechnical Standardization (CENELEC) band A and the test are done on a Chinese home environment where the Electric Power Research Institute (EPRI) specifies a 3 kHz to 500 kHz band. Results illustrating the effect of sunlight on this system are presented.
- Full Text:
- Authors: Nlom, S. M. , Ouahada, K. , Ndjiongue, A. R. , Ferreira, Hendrik C.
- Date: 2017
- Subjects: Narrowband PLC , VLC , S-FSK , PLC-VLC
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/237873 , uj:24379 , Citation: Nlom, S.M. 2017. Evaluation of the SFSK-OOK integrated PLC-VLC system under the influence of sunlight.
- Description: Abstract: With the widespread of light emitting diodes (LEDs) as a primary source of illumination, visible light communication (VLC) offers a lot of potentials by providing both resources and energy saving advantages. This paper presents a practical implementation of an integration of Power Line Communication (PLC) and VLC. The system uses spread frequency shift keying (S-FSK) and on-off keying (OOK) in the PLC and VLC channel respectively. The system is of low complexity, low cost and dedicated to enhance low data rate application of PLC technology. The practical design is compatible with the European Committee for Electrotechnical Standardization (CENELEC) band A and the test are done on a Chinese home environment where the Electric Power Research Institute (EPRI) specifies a 3 kHz to 500 kHz band. Results illustrating the effect of sunlight on this system are presented.
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Cancellation and error correction for narrowband interference with spectral nulls codes and OFDM modulation
- Ouahada, K., Ferreira, Hendrik C., Han Vinck, A. J., Snyders, A. J., Swart, Theo G.
- Authors: Ouahada, K. , Ferreira, Hendrik C. , Han Vinck, A. J. , Snyders, A. J. , Swart, Theo G.
- Date: 2007
- Subjects: Error-correcting codes (Information theory) , Spectral nulls codes
- Language: English
- Identifier: http://hdl.handle.net/10210/18135 , uj:15964 , Citation: Ouahada, K. et al. 2007. Cancellation and error correction for narrowband interference with spectral nulls codes and OFDM modulation. Proceedings of IEEE Africon, 26-28 September, 2007, Windhoek, Namibia.
- Description: Conference proceedings
- Full Text:
- Authors: Ouahada, K. , Ferreira, Hendrik C. , Han Vinck, A. J. , Snyders, A. J. , Swart, Theo G.
- Date: 2007
- Subjects: Error-correcting codes (Information theory) , Spectral nulls codes
- Language: English
- Identifier: http://hdl.handle.net/10210/18135 , uj:15964 , Citation: Ouahada, K. et al. 2007. Cancellation and error correction for narrowband interference with spectral nulls codes and OFDM modulation. Proceedings of IEEE Africon, 26-28 September, 2007, Windhoek, Namibia.
- Description: Conference proceedings
- Full Text:
A simplistic channel model for cascaded PLC-VLC systems
- Nlom, Stephane M., Ndjiongue, A. R., Ouahada, K., Ferreira, Hendrik C., Han Vinck, A. J.
- Authors: Nlom, Stephane M. , Ndjiongue, A. R. , Ouahada, K. , Ferreira, Hendrik C. , Han Vinck, A. J.
- Date: 2017
- Subjects: Channel model , Cascaded PLC-VLC , PLC and VLC channels
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/237866 , uj:24380 , Citation:
- Description: Abstract: In this a paper, we propose a simplistic channel model for cascaded PLC-VLC system which highlights the noise scenario in such hybrid systems. The model utilises previously proposed channel transfer functions of both PLC and VLC channels and highlights the effects of the LED supply in the system. The noise scenario implemented on the model is based on the observations obtained from a practical measurement of PLC and VLC noise amplitude spectrum (NAS). The PLC-VLC channel is generalised and then simulated based on realistic data. In our results, we highlight the effect of the model’s parameters and noise present in both PLC and VLC channels.
- Full Text:
- Authors: Nlom, Stephane M. , Ndjiongue, A. R. , Ouahada, K. , Ferreira, Hendrik C. , Han Vinck, A. J.
- Date: 2017
- Subjects: Channel model , Cascaded PLC-VLC , PLC and VLC channels
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/237866 , uj:24380 , Citation:
- Description: Abstract: In this a paper, we propose a simplistic channel model for cascaded PLC-VLC system which highlights the noise scenario in such hybrid systems. The model utilises previously proposed channel transfer functions of both PLC and VLC channels and highlights the effects of the LED supply in the system. The noise scenario implemented on the model is based on the observations obtained from a practical measurement of PLC and VLC noise amplitude spectrum (NAS). The PLC-VLC channel is generalised and then simulated based on realistic data. In our results, we highlight the effect of the model’s parameters and noise present in both PLC and VLC channels.
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A review of Bluetooth and NFC for financial applications
- Mngomezulu, Z., Rimer, S., Ouahada, K., Ndjiongue, A. R.
- Authors: Mngomezulu, Z. , Rimer, S. , Ouahada, K. , Ndjiongue, A. R.
- Date: 2017
- Subjects: NFC , Bluetooth , Security
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/237419 , uj:24322 , Citation: Mngomezulu, Z. et el. 2017. A review of Bluetooth and NFC for financial applications.
- Description: Abstract: Bluetooth and near field communications (NFC) are two of the most recently emerging wireless technologies [1] [2], largely because of the integral role they play in the Internet of everything (IoE). In this paper, the security aspect is evaluated for these two wireless technologies for potential applications in financial systems. Their frame size is also analyzed. This is done by reviewing their characteristics based on the state of the art and on the standards governing their deployment. It is found that Bluetooth has good security mechanisms when compared to NFC, which requires developers to implement their own security features at application level; however, NFC’s short range and its requirement for intentional communication between devices makes it inherently secure. It is also found that NFC has a larger message size, however, the classic Bluetooth message size is not that far below that of NFC data exchange format (NDEF) short records (SR) message size.
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- Authors: Mngomezulu, Z. , Rimer, S. , Ouahada, K. , Ndjiongue, A. R.
- Date: 2017
- Subjects: NFC , Bluetooth , Security
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/237419 , uj:24322 , Citation: Mngomezulu, Z. et el. 2017. A review of Bluetooth and NFC for financial applications.
- Description: Abstract: Bluetooth and near field communications (NFC) are two of the most recently emerging wireless technologies [1] [2], largely because of the integral role they play in the Internet of everything (IoE). In this paper, the security aspect is evaluated for these two wireless technologies for potential applications in financial systems. Their frame size is also analyzed. This is done by reviewing their characteristics based on the state of the art and on the standards governing their deployment. It is found that Bluetooth has good security mechanisms when compared to NFC, which requires developers to implement their own security features at application level; however, NFC’s short range and its requirement for intentional communication between devices makes it inherently secure. It is also found that NFC has a larger message size, however, the classic Bluetooth message size is not that far below that of NFC data exchange format (NDEF) short records (SR) message size.
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Wireless sensor node mobility and its effect on transmission reliability
- Ngandu, K. G., Nomatungulula, C. S., Rimer, S., Paul, B. S., Ouahada, K., Multi-hop routing
- Authors: Ngandu, K. G. , Nomatungulula, C. S. , Rimer, S. , Paul, B. S. , Ouahada, K. , Multi-hop routing
- Date: 2013
- Subjects: Wireless sensor networks , Mobile nodes
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/17439 , uj:15883 , Ngandu, K.G. et al. 2013. Wireless sensor node mobility and its effect on transmission reliability. IEEE AFRICOMM 2013, Malawi.
- Description: Abstract: Deploying a Wireless Sensor Network (WSN) poses certain challenges such as data reliability due to Electromagnetic Interference (EMI), multipath fading as well as faster energy depletion of nodes located near the base station creating communication holes in the network. Several energy efficient algorithms have been developed to improve the energy consumption of static nodes however the issue of battery depletion of nodes near the base station remains present. In this paper we attempt to model the relationship between the node mobility and the reliability of data transmission. Mobile nodes could move near static nodes experiencing high traffic in order to reduce the number of packets sent through the saturated nodes. This paper will investigate, using a real environment, the effect of speed and packet size on the reliability of the wireless link. This is a required prerequisite, prior to a detailed design of a Mobile relay node.
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- Authors: Ngandu, K. G. , Nomatungulula, C. S. , Rimer, S. , Paul, B. S. , Ouahada, K. , Multi-hop routing
- Date: 2013
- Subjects: Wireless sensor networks , Mobile nodes
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/17439 , uj:15883 , Ngandu, K.G. et al. 2013. Wireless sensor node mobility and its effect on transmission reliability. IEEE AFRICOMM 2013, Malawi.
- Description: Abstract: Deploying a Wireless Sensor Network (WSN) poses certain challenges such as data reliability due to Electromagnetic Interference (EMI), multipath fading as well as faster energy depletion of nodes located near the base station creating communication holes in the network. Several energy efficient algorithms have been developed to improve the energy consumption of static nodes however the issue of battery depletion of nodes near the base station remains present. In this paper we attempt to model the relationship between the node mobility and the reliability of data transmission. Mobile nodes could move near static nodes experiencing high traffic in order to reduce the number of packets sent through the saturated nodes. This paper will investigate, using a real environment, the effect of speed and packet size on the reliability of the wireless link. This is a required prerequisite, prior to a detailed design of a Mobile relay node.
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Mobile sink wireless underground sensor communication monitor
- Nomatungulula, C. S, Ngandu, K. G, Rimer, S., Paul, B. S., Longe, O. M., Ouahada, K.
- Authors: Nomatungulula, C. S , Ngandu, K. G , Rimer, S. , Paul, B. S. , Longe, O. M. , Ouahada, K.
- Date: 2013
- Subjects: Wireless sensor networks , Mobile sensor networks , Underground mobile processing
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/17421 , uj:15882 , Nomatungulula, C.S. et al. 2013. Mobile sink wireless underground sensor communication monitor. IEEE AFRICOMM 2013, Malawi.
- Description: Abstract: Mine disasters claim thousands of human lives and cause millions of property loss every year. The safety of the mine worker is of paramount importance in any underground environment. Advances in the development of Wireless Sensor Networks (WSNs) for monitoring infrastructure health, and environmental conditions provide end users with the benefit of low-cost installation, maintenance and scalability. This paper will investigate the challenges around a development of a real-time mine monitoring system using wireless sensor nodes to prevent mine disasters such as gas explosions or mine collapses. We propose a mobile, real-time gateway that will be able to process data collected from static wireless sensor nodes monitoring underground infrastructure, to prevent underground disasters.
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- Authors: Nomatungulula, C. S , Ngandu, K. G , Rimer, S. , Paul, B. S. , Longe, O. M. , Ouahada, K.
- Date: 2013
- Subjects: Wireless sensor networks , Mobile sensor networks , Underground mobile processing
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/17421 , uj:15882 , Nomatungulula, C.S. et al. 2013. Mobile sink wireless underground sensor communication monitor. IEEE AFRICOMM 2013, Malawi.
- Description: Abstract: Mine disasters claim thousands of human lives and cause millions of property loss every year. The safety of the mine worker is of paramount importance in any underground environment. Advances in the development of Wireless Sensor Networks (WSNs) for monitoring infrastructure health, and environmental conditions provide end users with the benefit of low-cost installation, maintenance and scalability. This paper will investigate the challenges around a development of a real-time mine monitoring system using wireless sensor nodes to prevent mine disasters such as gas explosions or mine collapses. We propose a mobile, real-time gateway that will be able to process data collected from static wireless sensor nodes monitoring underground infrastructure, to prevent underground disasters.
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Motion detection for home security with visible light communication
- Authors: Mhlabane, K. , Ouahada, K.
- Date: 2017
- Subjects: Visible light communication , LED , Phototransistor , Ndjiongue, R.
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/237427 , uj:24323 , Citation: Mhlabane, K., Ouahada, K. & Ndjiongue, R. 2017. Motion detection for home security with visible light communication.
- Description: Abstract: Visible Light Communication (VLC) is a technology that is fast becoming the alternative choice for wireless communication technologies. The technology uses light emitting diodes (LEDs) for both illumination and communication purposes. Current security systems use motion detection with infrared communication and/or camera technology. These systems are well known amongst intruders, making them vulnerable to tampering and even hacking. In this paper we present how can visible light technology can be used to detect any kind of motion and send an alarm to prevent any suspicion activity.
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- Authors: Mhlabane, K. , Ouahada, K.
- Date: 2017
- Subjects: Visible light communication , LED , Phototransistor , Ndjiongue, R.
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/237427 , uj:24323 , Citation: Mhlabane, K., Ouahada, K. & Ndjiongue, R. 2017. Motion detection for home security with visible light communication.
- Description: Abstract: Visible Light Communication (VLC) is a technology that is fast becoming the alternative choice for wireless communication technologies. The technology uses light emitting diodes (LEDs) for both illumination and communication purposes. Current security systems use motion detection with infrared communication and/or camera technology. These systems are well known amongst intruders, making them vulnerable to tampering and even hacking. In this paper we present how can visible light technology can be used to detect any kind of motion and send an alarm to prevent any suspicion activity.
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Experimental verification of frequency mappings with Hadamard transform for power line communications channel.
- Lukusa, T., Ouahada, K., Ndjiongue, A. R., Ferreira, Hendrik C., Han Vinck, A. J.
- Authors: Lukusa, T. , Ouahada, K. , Ndjiongue, A. R. , Ferreira, Hendrik C. , Han Vinck, A. J.
- Date: 2014
- Subjects: Power line communications channel , M-ary FSK modulation scheme , Electrical distribution networks
- Type: Article
- Identifier: uj:4773 , http://hdl.handle.net/10210/11956
- Description: In recent years, given the prominence of the electrical distribution network, power line communications channel has drawn interests among researchers throughout the globe. M-ary FSK modulation scheme has been extensively used when combined with certain error correcting codes because of its viability and robustness over the power line communications channel. In this paper, we make use of the sign changes property in the Hadamard transform combined together with convolutional codes and M-ary FSK modulation scheme to experimentally use the technique of ”frequency mappings” in a real power line environment. Interesting experimental results show that this technique is very useful without the need of combining coding techniques and modulations that is usually based on the combination of convolutional codes and M-FSK modulation schemes.
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- Authors: Lukusa, T. , Ouahada, K. , Ndjiongue, A. R. , Ferreira, Hendrik C. , Han Vinck, A. J.
- Date: 2014
- Subjects: Power line communications channel , M-ary FSK modulation scheme , Electrical distribution networks
- Type: Article
- Identifier: uj:4773 , http://hdl.handle.net/10210/11956
- Description: In recent years, given the prominence of the electrical distribution network, power line communications channel has drawn interests among researchers throughout the globe. M-ary FSK modulation scheme has been extensively used when combined with certain error correcting codes because of its viability and robustness over the power line communications channel. In this paper, we make use of the sign changes property in the Hadamard transform combined together with convolutional codes and M-ary FSK modulation scheme to experimentally use the technique of ”frequency mappings” in a real power line environment. Interesting experimental results show that this technique is very useful without the need of combining coding techniques and modulations that is usually based on the combination of convolutional codes and M-FSK modulation schemes.
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Error correction of frequency-selective fading channels with spectral nulls codes
- Ouahada, K., Ferreira, Hendrik C., Snyders, A. J., Han Vinck, A. J., Swart, Theo G.
- Authors: Ouahada, K. , Ferreira, Hendrik C. , Snyders, A. J. , Han Vinck, A. J. , Swart, Theo G.
- Date: 2007
- Subjects: Frequency-selective fading channels , Spectral nulls codes
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18126 , uj:15962 , Citation: Ouahada, K. et al. 2007. Error correction of frequency-selective fading channels with spectral nulls codes. Proceedings of IEEE Africon, 26-28 September, 2007, Windhoek, Namibia.
- Description: Abstract: In this paper, we investigate a prior error correction technique for frequency selective fading channels. Spectral nulls codes with nulls at submultiple frequencies are used to avoid fades at the corresponding frequencies. Coincide the spectrum null at the corresponding fading frequency and playing with its wideness, will minimize the bit errors caused by the channel.
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- Authors: Ouahada, K. , Ferreira, Hendrik C. , Snyders, A. J. , Han Vinck, A. J. , Swart, Theo G.
- Date: 2007
- Subjects: Frequency-selective fading channels , Spectral nulls codes
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18126 , uj:15962 , Citation: Ouahada, K. et al. 2007. Error correction of frequency-selective fading channels with spectral nulls codes. Proceedings of IEEE Africon, 26-28 September, 2007, Windhoek, Namibia.
- Description: Abstract: In this paper, we investigate a prior error correction technique for frequency selective fading channels. Spectral nulls codes with nulls at submultiple frequencies are used to avoid fades at the corresponding frequencies. Coincide the spectrum null at the corresponding fading frequency and playing with its wideness, will minimize the bit errors caused by the channel.
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Monitoring of the medication distribution and the refrigeration temperature in a pharmacy based on internet of things (IoT) technology
- Mambou, Elie N., Nlom, S. M., Swart, Theo G., Ouahada, K., Ndjiongue, A. R., Ferreira, Hendrik C.
- Authors: Mambou, Elie N. , Nlom, S. M. , Swart, Theo G. , Ouahada, K. , Ndjiongue, A. R. , Ferreira, Hendrik C.
- Date: 2016
- Subjects: Internet of things
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/123989 , uj:20860 , Citation: Mambou, E.N. et al. 2016. Monitoring of the medication distribution and the refrigeration temperature in a pharmacy based on internet of things (IoT) technology.
- Description: Abstract: For the past 15 years since its appearance, Internet of Things (IoT) technology has been leading the planet towards a smart world where all devices and physical objects, referred to as “things”, will be connected via electronic sensors through the Internet. The distribution of medication to patients at a pharmacy in certain regions is still very traditional and outdated. Patients wait for a long time in queues to receive their medications, this is mostly due to the absence of an efficient distribution system. Also, the refrigeration temperature within several pharmacies is a huge problem, as medications must be kept at a constant temperature for an optimal results...
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- Authors: Mambou, Elie N. , Nlom, S. M. , Swart, Theo G. , Ouahada, K. , Ndjiongue, A. R. , Ferreira, Hendrik C.
- Date: 2016
- Subjects: Internet of things
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/123989 , uj:20860 , Citation: Mambou, E.N. et al. 2016. Monitoring of the medication distribution and the refrigeration temperature in a pharmacy based on internet of things (IoT) technology.
- Description: Abstract: For the past 15 years since its appearance, Internet of Things (IoT) technology has been leading the planet towards a smart world where all devices and physical objects, referred to as “things”, will be connected via electronic sensors through the Internet. The distribution of medication to patients at a pharmacy in certain regions is still very traditional and outdated. Patients wait for a long time in queues to receive their medications, this is mostly due to the absence of an efficient distribution system. Also, the refrigeration temperature within several pharmacies is a huge problem, as medications must be kept at a constant temperature for an optimal results...
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Renewable energy solution for electricity access in rural South Africa
- Longe, O.M., Myeni, L., Ouahada, K.
- Authors: Longe, O.M. , Myeni, L. , Ouahada, K.
- Date: 2019
- Subjects: Electricity Access , HOMER Pro Software , Microgrid
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/404389 , uj:33911 , Citation: Longe, O.M., Myeni, L. & Ouahada, K. 2019. Renewable energy solution for electricity access in rural South Africa.
- Description: Abstract: South Africa has grown from 34% electrification in 1991 to about 84.7% electrification presently, but with least access to electricity in rural areas. The lower rate of electrification in rural areas than urban areas has made dwellers in rural unelectrified areas to be challenged economically, socially, educationally, health-wise, etc. The aging, unclean, nonrenewable and constrained traditional grid has necessitated to think out of the box for universal electricity access in the nation through renewable energy sources (RES) such as solar, wind, biomass, and hydro for rural electrification. Therefore, a RESpowered microgrid is designed for rural Jozini municipality with 26.3% electricity access. This proposed Jozini microgrid was found to have a Levelised Cost of Electricity (LCOE) of R0.384/kWh, which is about one-third of grid LCOE in South Africa. Also, the proposed Jozini microgrid has 0 kg/kWh CO2 emission compared to 0.99 kg/kWh CO2 emission from the traditional national grid.
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- Authors: Longe, O.M. , Myeni, L. , Ouahada, K.
- Date: 2019
- Subjects: Electricity Access , HOMER Pro Software , Microgrid
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/404389 , uj:33911 , Citation: Longe, O.M., Myeni, L. & Ouahada, K. 2019. Renewable energy solution for electricity access in rural South Africa.
- Description: Abstract: South Africa has grown from 34% electrification in 1991 to about 84.7% electrification presently, but with least access to electricity in rural areas. The lower rate of electrification in rural areas than urban areas has made dwellers in rural unelectrified areas to be challenged economically, socially, educationally, health-wise, etc. The aging, unclean, nonrenewable and constrained traditional grid has necessitated to think out of the box for universal electricity access in the nation through renewable energy sources (RES) such as solar, wind, biomass, and hydro for rural electrification. Therefore, a RESpowered microgrid is designed for rural Jozini municipality with 26.3% electricity access. This proposed Jozini microgrid was found to have a Levelised Cost of Electricity (LCOE) of R0.384/kWh, which is about one-third of grid LCOE in South Africa. Also, the proposed Jozini microgrid has 0 kg/kWh CO2 emission compared to 0.99 kg/kWh CO2 emission from the traditional national grid.
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