The Research And Implementation Of The Key Components In Ultra-Wideband Wireless Communication

Ultra-wideband (UWB) technology is one of the hot research areas in wireless communications in recent years. Many big companies, research centers and universities are doing UWB research. The research topics of UWB technology include radar UWB, low speed UWB communications, high speed UWB wireless personal communications, low speed UWB with location and penetration, etc. UWB signal has two basic forms: no-carrier UWB (NCUWB) and carrier UWB (CUWB). CUWB technology can be implemented using many schemes, such as CDMA-based on CUWB or OFDM-based on CUWB. The main contribution of the dissertation can be summarized as follows: In the conventional NCUWB system, impulse generator is one of the most unique and important components. We studied and made improvements on avalanche effect nanosecond impulser, and generated nanosecond UWB monocycle. To realize high-speed communication with NCUWB, impulser must have high repetition rate and be easy to integration. Above 100MHz repetition rate and sub-nanosecond impulser is designed, combined with filter technology.A circuit scheme of the DSSS-BPSK NCUWB system was proposed. The circuit bases on the BJT technology and has 5-volt power supply. Simulation results show that the stimulus signal can reach above 100MHz. This makes it qualify for high-speed applications.Viterbi decoder, which operates on above 60MHz, is designed and realized. Compared with tradional complex metric-computing clear-zero module, the decoder only adds a little slices and has no block RAM, so has very high decoding rate.