Research On Filter Bank Multicarrier System With Wide Sub-band And Its Key Technology

Filter bank multicarrier (FBMC) technology has become one of the core technology of next-generation broadband wireless communications system for its ability of flexible resource allocation、high spectral efficiency、anti- double-selective fading channel and better resolving the contradiction of high-speed wireless communications and complicated equalization. OFDM is a special case of FBMC which chose a rectangular pulse as the sending and receive filter, the rectangular pulse is a time-limited pulse, but with unlimited frequency domain expansion, therefore it has the capacity of anti-inter-symbol interference (ISI), but inter-carrier interference (ICI) is a serious shortcoming. And so in some application system, there is a need to consider a more comprehensive FBMC technology. This paper is a study on FBMC system with its sub-band broader, and the further using of the cyclic prefix as sub-band structure, this kind of system has a flexible resource allocation capabilities, lower spectral leakage, and equally low-complexity receiver with the OFDM, etc. It can especially used for asynchronous communication、cognitive radio systems and so on. This research paper gives the basic frame work of such systems.Paper first gives the wireless fading channel model and characteristics, which leads to a variety of wireless broadband transmission system that against the fading channel, including single-carrier system and several multi-carrier systems. Implementation structure、baseband equivalent model、differences and contact、advantages and disadvantages of OFDM、FMT、pulse shapeing multi-carrier system are analyzed with a unified FBMC system model. OFDM multi-carrier technology is a special case of FBMC with a rectangular pulse, does not suitable to all wireless communication situation, and this leads to design of the FBMC system which has a wider non-overlapping sub-band and with its sub-band further using single-carrier cyclic prefix (SCCP) structure.The SCCP-FBMC cascade system is the research framework and foundation of paper.Then, the paper designs two methods to improved FBMC system performance from a system point of view. Specifically, for the prototype pulse of FBMC, the impact of interference to the system is analyzed base on the prototype pulse. It is found that to FBMC system the signal-interference-ratio (SIR) depends on the channel scattering function and the corss-ambiguity function composed of prototype pulse, therefore the prototype pulse should have the homologous property.According to the demand of pulse property, a adaptive method that the prototype pulse changes according to the channel is proposed in FBMC systems, and the method is analyzed and verified according the corresponding adaptive design. Besides, another three-dimensional signal mapper is proposed and applied to the SCCP sub-system of SCCP-FBMC. A detailed mapping process and simulation is made, and experimental results show that the method is effective and reliable.Then paper discusses the channel estimation problem of SCCP subsystem. First the sub-band equivalent channel model of the cascade SCCP-FBMC system is analyzed and the equivalent design condition of equization which can be done in frequency domain is derived in SCCP subsystems. For most of the broadband wireless channel has a sparse characteristic, two estimation methods in the time-frequency domain used in sparse channel are proposed in SCCP systems. The first methods use frequency domain pilot, and with it the use of compressed sensing in sparse channel estimation is proposed and analyzed. This method can effectively improve the channel estimation performance of the precision; can also reduce the number of pilot requirements which lead to improved system efficiency. For time-domain training symbols, we propose a noise subspace-based channel estimation method for spase channel; this method has lower complexity and better performance than other algorithm such as GAIC etc. Finally, through simulation the effectiveness of these two methods is verified.Afterwards, equalization and detection in SCCP subsystem were studied. Detailed analysis of existent equalization and detection technology used in SCCP subsystem is obtained. Based on frequency domain equalization with time domain noise prediction, a noise prediction with iterative equalization techniques is proposed; the algorithm has a similar BER performance with Turbo equalization in time domain, but has a lower complexity. To further improve the detection performance,a list-based detection methods used in single-carrier frequency domain equalization is proposed, the algorithm is used in SCCP system after the conventional frequency domain equalization. Theoretical analysis and simulation show that with reasonable choice of parameters, it can achieve maximum likelihood detection performance with a lower complexity.Finally, the possibility of using multi-antenna technology in the SCCP-FBMC cascade system is discussed. Analysis and summary of multi-antenna technology, and its application in the FBMC is made. Two widely used multi-antenna technologies in the OFDM system, i.e. cyclic delay diversity and Alamouti space-time block codes, is discussed with its application in the SCCP-FBMC cascade system. Thesis put forward specific transceiver structure、the data processing of transceiver、and the selection of various parameters. Finally, through simulation the effectiveness and feasibility of the two multi-antenna technologies using in the SCCP-FBMC cascade system is verified.This paper focuses on the cascade system of SCCP-FBMC, discussed the system design、the receiver technology、and also multi-antenna technology etc. Moreover, despite the fact that the study of sub-band channel estimation and equalization is for SCCP subsystem of SCCP-FBMC, it can be applied directly in a separate SCCP system because of its same structure.