The Study Of CUWB Signal Generation Technology Which Has Flexible Spectrum Performance

With the rapid development of wireless communications, spectrum scarcity problem is increasingly severe. Cognitive Ultra-wideband (CUWB) technology has been majorly concerned because its capabilities of spectrum reuse and taking the chance of taking up spectrum. This paper presents a spectrum shaping optimization scheme based on MB-OFDM CUWB signals, which is introduce Partial Response System (PRS) while turning off sub-carriers. This scheme can deepen the spectrum notch almost without increasing system complexity.In this paper, we researched CUWB signal which has flexible spectral characteristics, especially the CUWB signals based on MB-OFDM and different kinds of spectrum shaping methods belonging to it. Among them, we focused on the method of closing OFDM sub-carriers and Active Interference Cancellation (AIC), doing some research on their principles and performance characteristics. On this basis, this paper presents a new spectrum shaping optimization solution of CUWB:the Partial Response System is introduced into the MB-OFDM CUWB signals while turning off some sub-carriers. Through the relevant coding in PRS, controllable interference which can be removed in the receiver without enhancing system complexity, is introduced to the CUWB signals. It can change spectrum shape of subcarriers of OFDM signals and deepen the spectrum notch. Detailed description of this method is presented in Chapter 4. We also did some simulations to demonstrate the effectiveness of this method in this chapter. In Chapter 5, different spectrum shaping techniques based on MB-OFDM CUWB are compared in this chapter. We sum up the advantages and disadvantages of these technologies and gave the best application environment of each method.