A new multiplexing technique based on the orthogonality of the signal waveform is proposed. It can bring extra capacity to the existing fiber-optic communication system. / A new multiplexing technique is proposed in this work, which is a promising alternative technique for next-generation high-capacity fiber-optic communication system. The concept of this technique is based on the orthogonality of the signal waveform. / Thesis / Master of Science (MSc) / A number of signals with orthogonal waveforms are multiplexed into a single optical fiber. In this scheme, the user’s information is encoded into the amplitude and the phase of the signal waveform. Then multiplexed signals can be transmitted through the fiber-optic communication system.