Synchronization and channel response estimation method suitable for OFDM system

Abstract

The invention relates to a synchronization and channel response estimation method which is applicable to an OFDM system, the technical proposal is as follows: a maximum likelihood criterion ML-based cost function for the symbol timing synchronization, the carrier frequency synchronization and the channel parameter joint estimation is proposed by using an OFDM system model under a frequency selective fading channel and against the requirements on the accuracy of the transmission of high-quality information of the next generation of wireless communication system and the existing OFDM wireless communication system. A system architecture and a strategy of joint estimation symbols of timing offset Theta, carrier frequency offset Epsilon and channel impulse response h are derived from the cost function. The method comprises the following steps of carrying out the coarse synchronization and the channel response estimation and carrying out the fine synchronization and the calculation of a channel estimated value. The method can realize the balance between the calculation precision and the calculation complexity, increase or reduce the times of the iteration of the fine synchronization according to an actual system, reduce the interference during the wireless transmission, further improve the reliability of the system and improve the availability of the system.

Description

technical field [0001] The invention relates to the field of wireless communication, in particular to a synchronization and channel response estimation method suitable for OFDM systems, and the invention belongs to the design applicable to the receiver end of the system. In the continuous improvement of the next-generation wireless communication system, it provides a new method of symbol timing synchronization, carrier frequency synchronization and channel parameter joint estimation based on maximum likelihood criterion and reliable communication support for the existing OFDM wireless communication system. It has the characteristics of rapidity and accuracy. Background technique [0002] With people's increasing demand for communication broadband, personalization and mobility, Orthogonal Frequency Division Multiplexing (OFDM) technology has been widely used in various wireless communication fields. The OFDM system is very sensitive to synchronization errors. When there are ...

AI Technical Summary

Problems solved by technology

[0003] At present, in the existing wireless OFDM system, there is a close relationship between symbol timing synchronization, carrier frequency synchronization and channel estimation, and the estimation error of delay and frequency offset will affect the accuracy of channel response estimation

Many approaches revolve around joint timing and frequency synchronization, but few have proposed the idea of ​​jointly estimating both synchronizations and channel impulse response

However, in practice, this strategy faces two major challenges

On the one hand, it is not easy to obtain the estimated values ​​of the three parameters at the receiving end of the system at the same time, and the calculation complexity is very high, which is not conducive to the application in the actual system

On the other hand, it is not easy to guarantee the performance of the system that jointly estimates the three parameters, and it is necessary to design a system that can meet the performance requirements of practical applications

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