Wireless Communications, Intelligent Signal Processing And Channel Coding Theory Research

Since the scarce of wireless spectrum, the paper advancely presents wireless system adopting Non-orthogonal intelligence signal processing to improve spectium efficiency. The thesis studies wireless system with general shared channels, focuses on Non-Orthogonal Multiplex Modulation and Multi-Address Access problems. We based on fundamental idea of NOMM proposed by Prof. Liang., DQ of Dalian Institute of Technique, expand to time, frequncy, code domain overlapped aceess system. The thesis firstly gives wavelet based system framework which integrates time, frequency, code and space domain. In channel coding, we originate bring forward using algebraical geometric code to improve system performance. System simulation and testing were carried out that based on OV-CDMA proposed by Lebanon scientist Elie Inalty, the validation of time-frequency complete code and overlapped structure of algebraic geometric code were proofed.The most innovation four aspects of the thesis are collected in the following:First, we construct N(OM)HDM structure based on Gabor time-frequency frame. NHDM is mixtured with time domain overlapped NTDM and frequency domain overlapped NFDM. The NFDM adapts fast Fourier Transform, while shift addition is used in time domain. When after Gabor Transformation, signal overlapped both in time domain and frequency domain will be applied simultaneously, the coefficients of filter bank are calculated by Zak transform, it has been proved such combination transformation can be implementing through Short Time FFT algorithm. We analysis the performance of such system, and prove the capacity of i.i.d parallel channels are less than those of shared channel. The NOMHDM with Gabor transform can achieve spectrum efficiency more than 6～10bps/Hz. The decoding algorithm is Brief Propagation, which based on Bayes analysis algorithm under research. After passing multi-level Gabor atom neural network, signal of flock users are classified, instead of find original code of each user, then the complex are largely decreased.Second, using the turbo like algebraic geometric coding on complex plan, this coded modulation method is the parallel transmission based on overlapped multiplexing of different path of complex domain code to get the natural restriction between them. Different to NOMTDM, the OV-CDM is fully characterized by its generator matrix. In this dissertation, we study the serials concatenation, parallel concatenation and matrix decoding of turbo like algebraic geometric code. Furthermore, structure of concatenate code with spectrum higher than 6 are studied, after optimization, we can approach the Shannon bound with less complex.Third, the multi-user OV-CDMA system use general complement code as its spread address codes. Since generation codes of each cell are completely orthogonal, the ACI (Adjacent Cell Interference) can be suppressed. So construction wireless network with frequency separation can largely suppress interference. The thesis deals with spread gain on both frequency and time domain. And the autocorrelation and cross correlation character of codes can be kept in high speed movement environment, and proved that OV-CDMA can support high speed environment. Through applying the fast sequential decoding and equilibrium algorithm, the system complexity can be largely reduced.Fourth, we explore explaining OV-CDMA the quantum entangle theory, and the overlapping multiple address access is the states entanglement in macro world, and multi-user can be detached when entangled. Algebraic geometric code with its elegant structure exhibits excellent mathematical precise and hardware implementation. The paper simulates these forms of LDPC and Density Evolution and EXIT chart optimize methods, which proved to be valid on TD-LTE system.Comparing with 4G LTE system with spectrum efficiency at 2-4bit/Hz/s per antenna, the structure proposed by the paper can achieve to 6-10b/Hz/s, whose threshold only be 1dB to Shannon's limitation. Traditional wireless system adopts Euclidean coordinate for coding and modulation, mean while the paper expands the coordinate to affine plan, so extending usable wireless resources and improving its efficiency. The advantage and validation of methods mentioned in the paper were proved through simulation and testing. The basic thoughts, discovery behind the thesis will provides new way for further academicals research in wireless communication system.