Abstract
Whether sending an image or a voice clip through a mobile device, making a call through a telephone line, listening to a particular radio station, or sending an email via a computer, data or information has to be transmitted from one point to another. Hence, this is the fundamental of data communication, which comprises multiple systems. The concept was introduced decades ago, it has been developed and evolved to suit the current need for communication and current and future technology. A data communication system's paramount components are a modulator (transmitter) and a demodulator (receiver) and integrating these two to form a modem. This dissertation focuses on implementing a single-directional modem device based on a Spread Frequency Shift Keying (S-FSK) modulation technique, focusing on the transmitter, receiver, data signal and performance.
A comprehensive review of data communication is conducted, where the transmission medium based on a Power-line Communication (PLC), the standards governing the Power-line Communication (PLC) technology, frequency band operation, modulation techniques, demodulation, Frequency Shift Keying (FSK) and S-FSK is reviewed. The S-FSK modem is implemented such that its design is based on a Narrow-Band frequency with high data rate transmission, thus utilising the frequency band of 145.3 kHz to 478.125 kHz from the Federal Communication Commission (FCC) of the USA. Modified filter-type demodulation based on non-coherent FSK demodulation with spectrally matched filters and envelope detection technique is used for demodulation at the receiver.
The performance analysis was conducted by theoretically deriving the Signal-to-Noise ratio, Probability of Error, and BER. The BER performance was further analysed based on the implemented design by doing a comparative analysis based on Random data sources (Bernoulli Binary generator, Poisson Integer Generator, and Random integer generator). An experimental practical analysis was conducted from the constructed prototype, where functional tests and performance tests were conducted in the absence and also in the presence of a PLC medium. The findings from the modem implementation tests and its performance analysis were compared and presented.
Keywords - Spread-Frequency Shift Keying, Frequency Shift Keying, Power-Line Communication, Modulation, Demodulation, Filters, Modems, Bernoulli Binary, Poisson Integer, Random Integer Signal to Noise Ratio and Bit Error Rate.