Research On Theory And Applications Of Inner Receiver For New Generation Mobile Communication Systems

Frequency selective channel is one of the important problems in new generation mobile communications, and equalization technologies are applied to combat the influence of this channel. In order to degrade the complexity of equalizers, block transmission is preferred in modern wireless communications, such as CP-SCBT (Cyclic Prefix Single Carrier Block Transmission) systems and OFDM (Orthogonal Frequency Division Multiplexing) systems. How to efficiently maintain synchronization and estimate the channel parameters in time-varying channels become one of the main problems for inner receiver, which are worth lucubrating. This dissertation mainly focuses on the inner receiver techniques for block transmission mobile communication systems, such as channel parameters estimation and synchronization techniques.This dissertation includes eight chapters. Chapter one gives background and chapter two introduces the channel characters of the mobile communications and gives the basic concept of CP-SCBT systems and OFDM systems.In chapter three, the envelope statistical characteristics of radio channels are researched in time domain, including LCR (Level Crossing Rate), ROM (Rate of Minimum) and logarithmic envelope autocorrelation. Then the Doppler shift estimators based on the above statistics are proposed for Rayleigh channel, and the modifications are proposed to degrade complexity and improve performance according to the theoretical estimation error. Both theoretic and numerical results show good performance of these estimators.In chapter four, the phase statistical characteristics of radio channels are researched in time domain, and the PDF (Probability Density Function) of phase difference is derived in close-form expressions. Then moments of the PDF are analyzed and the Doppler shift estimators based on moments are proposed with the modifications analogous to that in chapter three. Finally, both adaptive slot structure method and adaptive WMSA (Weight Multi-Slot Average) algorithm are proposed to reduce the pilot spending and improve precise of channel estimation by utilizing the Doppler shift estimates, which are simple and effective as shown in simulation.Based on PSAM (Pilot Symbol Assisted Modulation) block transmission mobile communication systems, the joint estimating algorithm suitable for synchronization tracking stage is proposed in chapter five. By making use of sub-space separation of transform domain, the Doppler shift , CFO (Carrier Frequency Offset) and SNR (Signal-to-noise Ratio) are estimated together through one unified estimator structure. Compared with traditional independent estimator...