Channel Estimation In Single Carrier Frequency-Domain Equalization System

With People's increasing requirements for all kinds of real-time multimedia service and the rapid development of the Internet, broadband wireless communication has become a full potential in the development of wireless communication..In the system of wireless broadband communication, the multi-path effect may greatly affect the reliability of the communication performance.Therefore,how to enhance the transmission efficiency of the system is closely related to the scheme adopted for countermining the channel multi-path effect.Firstly, this thesis introduces the characteristics of radio channels, and then, it researchs on the basic principle of SC-FDE system, gives the model of system and key technology. Furthermore, based on the theory of Bayesian estimation, it researches the particl filter. A set of particles, which are randomly sampled from probability function and have corresponding weights, are introduced to approach the posterior distribution. Therefore it suits for nonlinear and non-Gaussian problems which can be expressed by state-space model.Particle filter is used in channel estimation of SC-FDE time-varying system through establishing the state-space of SC-FDE channel estimation, and then the particle filter algorithm in channel estimation is received.Finally, simulate to compare the particle filter channel estimation algorithm with the traditional method of channel estimation performance.However, there are still some existing problems, such as weight degeneracy, sample impoverishment.When it is used in SC-FDE channel estimation, the algorithm should be improved. In order to reduce the ratio in bit error rate, this paper improves the performance of particle filter in two aspects:importance samplings function and resample, and gives the simulation effect analysis.The simulation result proves that the improved method can increase accuracy of channel estimation in SC-FDE and reduce the bit error rate.