OFDM communication system carrier blind frequency-offset estimating method

Abstract

The present invention discloses a blind frequency offset estimation method for an OFDM system, aiming at the disadvantages of the existing blind frequency offset estimation method, such as the large amount of calculation of the singular value decomposition of the covariance matrix, and the existence of uncertainty in the frequency selective channel. , the method assigns virtual subcarriers at equal intervals at the transmitter, constructs a low-dimensional autocovariance matrix through undersampling at the receiver, and finally uses the subspace method to decompose the obtained covariance matrix to obtain the carrier frequency offset estimate. The method of the invention can overcome the uncertainty under the frequency selective channel, and at the same time can provide a closed analytical solution, not only greatly reducing the amount of calculation, but also significantly improving the estimation performance.

Description

technical field [0001] The invention relates to a method for estimating frequency offset of a carrier in an OFDM communication system, in particular to a method for estimating a blind frequency offset of a carrier in an OFDM communication system. Background technique [0002] In the wireless communication system, OFDM (Orthogonal Frequency Division Multiplexing) technology is the core technology of the fourth generation mobile communication system and has been adopted by many industrial standards. However, the OFDM system is very sensitive to the carrier frequency offset between the transmitter and receiver. The existence of carrier frequency offset will cause the loss of orthogonality among sub-carriers, resulting in inter-carrier interference and greatly reducing the performance of the system. Therefore carrier frequency offset estimation and compensation is a key technology of OFDM system. [0003] There are many methods for estimating the carrier frequency offset of OF...

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Problems solved by technology

[0006] The present invention provides a blind frequency offset estimation method for an OFDM system, aiming at the shortcomings of the existing blind frequency offset estimation method, such as the large amount of calculation of the singular value decomposition of the covariance matrix, and the uncertainty in the frequency selective channel. , this method can overcome the uncertainty in the frequency selective channel by allocating virtual subcarriers at equal intervals at the transmitter and constructing a low-dimensional autocovariance matrix at the receiver through undersampling, and at the same time can give a closed-form Analytical solution, not only the amount of calculation is greatly reduced but also the estimation performance is also significantly improved

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