Synchronization And Channel Estimation Of Multi-carries Communication Systems

Wireless multi-carries Multiple Input Multiple Output (MIMO) and Orthogonal Frequency Division Multiplexing (OFDM) are promising techniques in wireless communication systems. Synchronization and channel estimation are key techniques in wireless OFDM systems. The dissertation will focus on the training symbol aided synchronization and channel estimation techniques in multi-carries systems through plenty of simulation. In the synchronization estimation in multi-carries MIMO-OFDM transmission systems, a new training sequence aided synchronization algorithm and the corresponding algorithm are proposed based on the available classic algorithms based on sequence orthogonal or time orthogonal training sequence. The new algorithm firstly designs a new constant amplitude zero correlation (CAZAC) sequence, then uses the sequence to estimate timing and frequency offset, and improves the estimation performance. In the residual synchronization error estimation in OFDM transmission systems, a new residual synchronization estimation method is proposed based on the available pilot tone assisted (PTA) residual synchronization estimation methods. The new method improves the estimation performance. In the channel estimation, a new channel estimation method is proposed after analysizing and simulating the available channel estimation method based on least square (LS) criteria and space time clock coding. In the new method, the training sequences are formed with CAZAC sequences with different cyclic shift for different transmit antennas. The new method improves the estimation performance through the time-domain correlation between the received training sequences and local training sequences.