Realization of pulse shaping in high frequency communication systems by using harmonic generation for different modulation techniques

The increasing volume of data in communication systems demands higher bandwidth. One of the best solutions to meet this demand is the use of the millimeter wave (mmWave) band. However, since there are no components that directly generate signals in the mmWave band, frequency multipliers are used. Although systems with high carrier frequencies utilizing these components exist, standard communication models are not suitable for data transmission in this band, and issues arise in data recovery. This thesis presents methods for solving these issues and improving system performance for different modulation types. In the thesis, the effects of frequency upconversion through harmonic frequency multiplication on the transmitted data pulse shape and data rate have been investigated. The results show that through pulse shaping, the signal-to-noise ratio (SNR) of the transmitted data eye diagram can be improved by 3 dB or the data rate can be increased by 20 percent. Additionally, the use of the Faster-than-Nyquist (FTN) transmission method with a harmonic receiver has been investigated. Simulation results indicate that the harmonic receiver improves system performance within a certain FTN factor range. The thesis proposes a novel constellation modification method for MPSK data transmission utilizing the frequency multiplication in the mmWave band. It confirms that the modified MPSK modulator enhances error performance without altering the receiver. Finally, the thesis aims to achieve data transmission in the mmWave band using an experimental system compatible with frequency multiplication. In this context, harmonic modulated MPSK data transmission was conducted at 30 GHz, achieving harmonic modulated BPSK data transmission with a 2.3 dB power penalty. The improvement in the system's error performance demonstrates the effectiveness of the proposed method and its suitability for harmonic modulated MPSK data transmission in the mmWave band.