Research On The Key Technologies Of Filtered Multi-Tone Modulation In Mobile Environment

With the rapid development of our society, people have a greatly improved requirement for wireless data transmission. High bandwidth and high reliability becomes the final goal of modern mobile communication technology. At present the 3rd generation mobile communication system (3G) has been put into commercial use; Beyond 3rd (B3G) or 4th generation (4G) mobile communication system TD-LTE technology has also been successfully tested in the World Expo 2010 Shanghai and the related key technologies are ready on the whole. The development of communication technology makes the distance between people shorter and shorter, and plays a more and more significant role in the development of the whole society. As an important branch of communication technology, wireless communication has become one of the fastest growing technologies, and has become an important symbol of social development.However, the actual mobile communication system is facing many complex problems. Multipath, frequency shift, noise, multi-access interference, inter-symbol interference and bandwidth limitations have seriously affected the quality of communication links and system capacity, and have become the key factors restricting rapid development of communication. With the improvement of bandwidth, multipath problems and Doppler effect are more and more difficult to overcome for single-carrier communication. OFDM, as a representative of multi-carrier technologies, has outstanding performance in anti-multipath and attracted extensive attention. However, OFDM technology also has some defects, such as the sensitivity to frequency offset and phase offset, the need of strict timing and synchronization and the need of virtual carriers and cyclic prefix to ensure the orthogonality among subcarriers, which reduce the system spectrum efficiency and increase the system cost. As one of the multi-carrier technologies, FMT technology also has good anti-multipath ability. Comparing with OFDM technology, pulse shaping with the sampling function waveform in frequency-domain, FMT, which uses rectangular waveform in the frequency-domain, has better anti-offset and anti-crosstalk ability.This paper mainly researches on prototype filter design of FMT system, PAPR analysis, cascade with channel coding, relevant code FMT system and other aspects. The main academic contributions of this paper are as following:a. To study the PAPR problem of FMT system. Extreme value theory is adopted to deduce complementary cumulative distribution function (CCDF). According to CCDF, we analyze PAPR and the relationship between the filter type and the length, which provides guidance for FMT system. Based on the CCDF of FMT signal we study PTS method to reduce the PAPR in FMT system.b. To conduct prototype filter design with convex optimization techniques. Inter-symbol interference (ISI) and inter-channel interference (ICI) of FMT system are analyzed, prototype filter design with convex optimization techniques which adopts ISI and ICI as constraints is studied and the ISI problem caused by traditional method approaching ideal low-pass design is overcome.c. FMT system and Turbo coding cascade design. We separately study FMT system cascade with serial and parallel Turbo coding scheme, propose corresponding likehood ratio method and compare the performance under different channel environment, for different modulation types and bit rates. Then we use EXIT (Extrinsic Information Transfer) chart to analyze iterative performance of the proposed scheme.d. Research on partial response FMT technology. In order to solve the ISI problem caused by frequency-domain rectangular shape, we put forward a partial response FMT system. We want to keep FMT sub-channel spectrum strict constraint by using partial response technique on sub-channel, while at the same time, optimize the time-domain impulse response waveform and reduce the ISI. Finally, we discuss the anti-noise performance of partial response FMT system in the AWGN channel and the equalization scheme in partial response FMT system.Finally, we summarize the problems to be solved in our fields and future research topics; furthermore, the prospect of the developing tendency is analyzed as well.