SC-FDE System Channel Estimation And Equalization Algorithm

The single carrier frequency domain equalization is a new broadband wireless communication technology. SC_FDE system combined with the advantages of the traditional single-carrier transmission and OFDM technology. Recur to training sequence and the frequency domain equalizer, SC_FDE system avoids the complexity of SC_TDE and high PAPR of OFDM. Become an important technology for the physical layer of broadband wireless access systems. One of the most challenging problems in high rate wireless communication is to overcome the effect caused by multipath propagation. So, this thesis mainly research SC_FDE system channel estimation and frequency domain equalization technology.Firstly, the main characteristics of the radio channel propagation environment are analyzed, and the schematic diagram and mathematical description for SC_FDE system are given. And researches the data frame structure of the transmission signal, then describes the pilot signal UW (unique word) generation method. To achieve zero forcing (ZF) and minimum mean square error (MMSE) equalization simulation experiment, and simulation results show that the performance of the MMSE equalization better than ZF equalization.Then, constructs the SUI channel simulation model according to the characteristics of the wireless channel parameters based on the SUI channel model proposed by IEEE802.16standard. Researches the unique word (UW) in depth and analyzes the impact of the UW length of the system performance. Simulation results have shown that the accuracy accompanied by the increase of the length, but it will be lower bandwidth efficiency. Therefore, to solve this problem, an improved data frame structure is proposed. And the new frame structure improves the accuracy of channel estimation without the bandwidth efficiency addition. At last, simulation results verify the performance of the improved data frame structure is better.Finally, the frequency domain equalization principle for SC_FDE system is discussed and simulates the equalizer system performance. Owing to MMSE equalization still exists the residual inter-symbol interference. This thesis analyzes the noise prediction algorithm for MIMO-SCFDE system, and optimizes the noise prediction algorithm parameter. Then, MMSE-RISIC algorithm and noise prediction algorithm are weighted to form the MMSE-NP-RISIC algorithm, and the various equalization algorithm flowcharts are given. Finally, compares and analyzes the system performance of different equalization algorithm. The new combination algorithm taking into account the inter-symbol interference and noise interference, and simulation experiments verify the new combination algorithm has better performances.