Performance analysis of x-frequency shift keying based communication systems for power line and visible light communications channels
- Mougoue Yamga, Gabriel Melchiade
- Authors: Mougoue Yamga, Gabriel Melchiade
- Date: 2018
- Subjects: Data transmission systems , Radio frequency modulation , Electric lighting , Electric lines
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/293738 , uj:31946
- Description: Abstract: Power line communications (PLC) and visible light communications (VLC) are two emerging telecommunication technologies which may be seriously considered in the near future. This is due to the fact that both technologies present a channel or antennas, normally used for other purposes. The power wires which constitute the PLC channel are primarily exploited for electrical energy transmission, and the light bulbs which are VLC transmitting antennas are sources of illumination. PLC and VLC technologies also present four meaningful similarities: (i) Impulsive noise is the most destructive PLC noise, it is modelled using Poisson distribution. Similarly, the VLC channel is dominated by shot noise, also modelled using the same statistical distribution. (ii) Multiple reflections of the transmitted signal characterise the PLC channel. This is similar to the multipath propagation of VLC, which is due to multiple reflections that light rays undergo in the transmission environment. (iii) PLC technology presents economic advantages owing to the fact that it uses ubiquitous power wires already installed. This is the case of VLC technology, which uses the omnipresent light bulbs, naturally used for illumination. (iv) Both power wires and light bulbs are physically connected; light bulbs are powered through power wires. These similarities, added to the fact that both PLC and VLC are naturally connected to each other (light sources receive electrical energy from the electrical cable), are advantages related to cost effectiveness which is of a great importance in engineering. Among the applications of these two communication technologies, some are low data rate based. Generally, these low data rate applications require a modulation technique different from those exploited in high data applications. Lots of low data rate modulation schemes are used in communication engineering, they include on-off keying (OOK), pulse position modulation (PPM) and its variances, and frequency shift keying (FSK), to mention only... , M.Ing. (Electrical Engineering)
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- Authors: Mougoue Yamga, Gabriel Melchiade
- Date: 2018
- Subjects: Data transmission systems , Radio frequency modulation , Electric lighting , Electric lines
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/293738 , uj:31946
- Description: Abstract: Power line communications (PLC) and visible light communications (VLC) are two emerging telecommunication technologies which may be seriously considered in the near future. This is due to the fact that both technologies present a channel or antennas, normally used for other purposes. The power wires which constitute the PLC channel are primarily exploited for electrical energy transmission, and the light bulbs which are VLC transmitting antennas are sources of illumination. PLC and VLC technologies also present four meaningful similarities: (i) Impulsive noise is the most destructive PLC noise, it is modelled using Poisson distribution. Similarly, the VLC channel is dominated by shot noise, also modelled using the same statistical distribution. (ii) Multiple reflections of the transmitted signal characterise the PLC channel. This is similar to the multipath propagation of VLC, which is due to multiple reflections that light rays undergo in the transmission environment. (iii) PLC technology presents economic advantages owing to the fact that it uses ubiquitous power wires already installed. This is the case of VLC technology, which uses the omnipresent light bulbs, naturally used for illumination. (iv) Both power wires and light bulbs are physically connected; light bulbs are powered through power wires. These similarities, added to the fact that both PLC and VLC are naturally connected to each other (light sources receive electrical energy from the electrical cable), are advantages related to cost effectiveness which is of a great importance in engineering. Among the applications of these two communication technologies, some are low data rate based. Generally, these low data rate applications require a modulation technique different from those exploited in high data applications. Lots of low data rate modulation schemes are used in communication engineering, they include on-off keying (OOK), pulse position modulation (PPM) and its variances, and frequency shift keying (FSK), to mention only... , M.Ing. (Electrical Engineering)
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Aspects of dedicated (dormant) chip for intelligent part handling by industrial robots
- Authors: Theron, Stephanus Andreas
- Date: 2012-09-12
- Subjects: Radio direction finders , Radio frequency , Radio frequency modulation , Radio beacons - Design , Industrial robots
- Type: Thesis
- Identifier: uj:10249 , http://hdl.handle.net/10210/7620
- Description: M.Ing. , Intelligent object identification (the ability to find the identity, position and orientation of an remote object) in a Manufacturing environment plays an important role in the areas of Automation and Manufacturing. Radio frequency identification (RFID) systems have solve the problem of finding the identity of a remote object, but it fails to determine the position and orientation. The Global Positioning System (GPS) have a solution to find the position of a remote object in the global environment, but in a Manufacturing environment it fails. The main obstacle to overcome in finding a unique solution with radio frequency technology is reflections. This thesis investigates the idea of finding the identity, position (and orientation) of a (dormant) chip remotely. The chip transmits a binary signal at 244kHz. The string is Amplitude modulated. The receiver demodulates the signal to obtain the chip's identity. The receiver antenna is divided into four quadrants. First the quadrant in which the chip is located are determined. Three different voltages are then measured to obtain the position of the chip in the specific quadrant. Reflections can be ignored since the system works at a low frequency.
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- Authors: Theron, Stephanus Andreas
- Date: 2012-09-12
- Subjects: Radio direction finders , Radio frequency , Radio frequency modulation , Radio beacons - Design , Industrial robots
- Type: Thesis
- Identifier: uj:10249 , http://hdl.handle.net/10210/7620
- Description: M.Ing. , Intelligent object identification (the ability to find the identity, position and orientation of an remote object) in a Manufacturing environment plays an important role in the areas of Automation and Manufacturing. Radio frequency identification (RFID) systems have solve the problem of finding the identity of a remote object, but it fails to determine the position and orientation. The Global Positioning System (GPS) have a solution to find the position of a remote object in the global environment, but in a Manufacturing environment it fails. The main obstacle to overcome in finding a unique solution with radio frequency technology is reflections. This thesis investigates the idea of finding the identity, position (and orientation) of a (dormant) chip remotely. The chip transmits a binary signal at 244kHz. The string is Amplitude modulated. The receiver demodulates the signal to obtain the chip's identity. The receiver antenna is divided into four quadrants. First the quadrant in which the chip is located are determined. Three different voltages are then measured to obtain the position of the chip in the specific quadrant. Reflections can be ignored since the system works at a low frequency.
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Channel characterisation and coding for the FM SST channel
- Authors: Albertyn, Eben
- Date: 2011-11-10
- Subjects: Signal processing , Digital communications , Radio frequency modulation , FM broadcasting
- Type: Thesis
- Identifier: uj:7269 , http://hdl.handle.net/10210/3944
- Description: M.Ing. , The transmission of digital data at higher data rates and greater reliabilities is becoming increasingly more important in the society of today. The usage of, especially wireless digital data, is increasing at an alarming rate, and the need arises for more bandwidth to be made available for this purpose. Hence, the need arises to optimise and expand the usage of bandwidth currently under use. Existing wireless channels, such as the commercial FM service, need to be re-evaluated and unused bandwidth needs to be developed and used as close to capacity as possible. In this dissertation, a study was launched to develop the FM SST (Supplementary Signal Transmission) commercial analog service as a simplex digital channel that can commercially be used to transmit a myriad of digital data. With the help of a commercial FM radio channel, digital data was transmitted using a number of different modulation schemes to obtain channel measurements for the FM SST channel. The modulation scheme that performed the best, given certain criteria, was GMSK. This raw information was then used to extract first and higher order statistical information from the channel, in order to parameterise discrete channel models, based on a Markov process. The channel models that were used were the Gilbert, GilbertElliott and Fritchman channel models. These channel models were then tested according to their iirst and higher order statistical data to evaluate their effectiveness in modelling the error process on the FM SST channel. It was found that the channel model best approximating the real channels was the Gilbert channel. Once satisfactory results were obtained, these discrete channel models were then used to evaluate various error correction schemes for their ability to correct burst errors on the FM SST channel. From the various schemes evaluated, a (63,39) BCH with an interleaver of index 4 was found to perform the best. The purpose of which is to transmit digital data at the highest data rate possible and at the same time having a bit error rate less than lxl0-6.
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- Authors: Albertyn, Eben
- Date: 2011-11-10
- Subjects: Signal processing , Digital communications , Radio frequency modulation , FM broadcasting
- Type: Thesis
- Identifier: uj:7269 , http://hdl.handle.net/10210/3944
- Description: M.Ing. , The transmission of digital data at higher data rates and greater reliabilities is becoming increasingly more important in the society of today. The usage of, especially wireless digital data, is increasing at an alarming rate, and the need arises for more bandwidth to be made available for this purpose. Hence, the need arises to optimise and expand the usage of bandwidth currently under use. Existing wireless channels, such as the commercial FM service, need to be re-evaluated and unused bandwidth needs to be developed and used as close to capacity as possible. In this dissertation, a study was launched to develop the FM SST (Supplementary Signal Transmission) commercial analog service as a simplex digital channel that can commercially be used to transmit a myriad of digital data. With the help of a commercial FM radio channel, digital data was transmitted using a number of different modulation schemes to obtain channel measurements for the FM SST channel. The modulation scheme that performed the best, given certain criteria, was GMSK. This raw information was then used to extract first and higher order statistical information from the channel, in order to parameterise discrete channel models, based on a Markov process. The channel models that were used were the Gilbert, GilbertElliott and Fritchman channel models. These channel models were then tested according to their iirst and higher order statistical data to evaluate their effectiveness in modelling the error process on the FM SST channel. It was found that the channel model best approximating the real channels was the Gilbert channel. Once satisfactory results were obtained, these discrete channel models were then used to evaluate various error correction schemes for their ability to correct burst errors on the FM SST channel. From the various schemes evaluated, a (63,39) BCH with an interleaver of index 4 was found to perform the best. The purpose of which is to transmit digital data at the highest data rate possible and at the same time having a bit error rate less than lxl0-6.
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