- Tanzania, United Republic of
Nerey Mvungi
University of Dar es Salaam, Computer Science and Engineering, Faculty Member
Research Interests:
Research Interests:
This paper presents the influencing of load impedance, line length and branches on the performance of medium voltage power line communication (PLC) network. The power line network topology adopted here is similar to that of the system in... more
This paper presents the influencing of load impedance, line length and branches on the performance of medium voltage power line communication (PLC) network. The power line network topology adopted here is similar to that of the system in Tanzania. Different investigation with regard to network load impedances, direct line length (from transmitter to receiver), branched line length and number of branches has been investigated. From the frequency response of the transfer function (ratio of the received and transmitted signal), it is seen that position of notches and peaks in the magnitude responses are largely affected in terms of attenuation and dispersion by the above said network parameters/configuration. The observations presented in the paper could be helpful in suitable design of the PLC systems for a better data transfer and system performance.
Research Interests:
Research Interests:
Research Interests:
This paper presents the influencing of load impedance, line length and branches on the performance of medium voltage power line communication (PLC) network. The power line network topology adopted here is similar to that of the system in... more
This paper presents the influencing of load impedance, line length and branches on the performance of medium voltage power line communication (PLC) network. The power line network topology adopted here is similar to that of the system in Tanzania. Different investigation with regard to network load impedances, direct line length (from transmitter to receiver), branched line length and number of branches has been investigated. From the frequency response of the transfer function (ratio of the received and transmitted signal), it is seen that position of notches and peaks in the magnitude responses are largely affected in terms of attenuation and dispersion by the above said network parameters/configuration. The observations presented in the paper could be helpful in suitable design of the PLC systems for a better data transfer and system performance.
Research Interests:
Research Interests:
This paper presents the influencing of load impedance, line length and branches on the performance of medium voltage power line communication (PLC) network. The power line network topology adopted here is similar to that of the system in... more
This paper presents the influencing of load impedance, line length and branches on the performance of medium voltage power line communication (PLC) network. The power line network topology adopted here is similar to that of the system in Tanzania. Different investigation with regard to network load impedances, direct line length (from transmitter to receiver), branched line length and number of branches has been investigated. From the frequency response of the transfer function (ratio of the received and transmitted signal), it is seen that position of notches and peaks in the magnitude responses are largely affected in terms of attenuation and dispersion by the above said network parameters/configuration. The observations presented in the paper could be helpful in suitable design of the PLC systems for a better data transfer and system performance.
Research Interests:
Researchers have shown that practical mobile communication channels introduce errors that are concentrated in a certain locality rather than random errors. These are burst errors caused by deep fading of the wireless channel or a... more
Researchers have shown that practical mobile communication channels introduce errors that are concentrated in a certain locality rather than random errors. These are burst errors caused by deep fading of the wireless channel or a lightning strike. The existing Viterbi Algorithm (VA) capable of correcting random errors is inefficient in correcting burst errors and therefore resulting in unacceptable amount of residual errors. This paper presents an assessment of Non- Transmittable Codewords (NTCs) enhancement technique to VA in decoding the received signals subjected to burst errors that may occur in poor channels. A hard decision, 1/2 rate and constraint length K is equal to 3 Viterbi Algorithm decoding technique, Binary Phase- Shift Keying (BPSK) and Additional White Gaussian Noise (AWGN) are components used in MATLAB software based simulation when assessing the proposed technique. Applying 6NTCs to VA decoder enables the decoder to reduce 83.7 percent of its residual errors. However, the technique reduces the encoder’s data transmission rate from 1/2 to 1/6.
Research Interests:
Research Interests:
The Viterbi decoder is the most favorable solution to the problem of decoding codewords from a convolutional encoder. Viterbi decoder performs exceptionally well when a received codewords block contains single or multiple and scattered... more
The Viterbi decoder is the most favorable solution to the problem of decoding codewords from a convolutional encoder. Viterbi decoder performs exceptionally well when a received codewords block contains single or multiple and scattered errors in a received codewords block. However, the formation of burst errors in data transmission due to high transmission speed and the widely varying error conditions of wireless media in fading channel creates decoding challenge for such conditions which result in unbearable amount of residual errors. By using Viterbi decoders’ trellis diagrams, this paper analyses the effects of burst errors to the decoder that lead to residual errors and proposes improvement to the encoding and decoding procedures of the existing (2, 1, 2) binary convolutional encoder. The improved version facilitate effectiveness in the decoder (Viterbi algorithm) in decoding burst errors and hence reduction of residual errors in a poor channel. The proposed enhancements improve the decoder’s operational performance by 75 percent. However, the proposed modification reduces the encoder’s data transmission rate from 1/2 to 1/6.
https://sites.google.com/site/ijcsis/
https://sites.google.com/site/ijcsis/