Underwater acoustic OFDM time-varying channel estimation method based on sparse Bayesian learning

Abstract

The present invention relates to an underwater acoustic OFDM time-varying channel estimation method based on sparse Bayesian learning. The method comprises the following steps of: the step 1: inputting channel estimation parameters, wherein the parameters comprise a receiving symbol vector YP, a dictionary matrix [Phi]p, the maximum iterations rmax, a termination threshold e and a noise variance [Sigma]2; the step 2: initializing a hyper-parameter matrix [Gamma] and an iteration count r; the step 3: employing the expectation maximization algorithm to perform solution of a hyper parameter [gamma]; the step 4: performing iteration terminal condition determination, wherein if r<rmax and a formula is met as shown in the description, r=r+1, and the step 3 is returned, if r<rmax and a formula ismet as shown in the description, iteration is terminated, and if r>=rmax, the iteration is terminated; and the step 5: outputting an estimation parameter, comprising sparse channel vector estimationand hyper parameter vector estimation. Compared to a current CS method, the method provided by the invention can improve the precision of the channel estimation, can reduce the system error rate, andhas an actual application value in the actual underwater acoustic OFDM communication system.

Description

technical field [0001] The invention relates to an underwater acoustic OFDM time-varying channel estimation method, in particular to an underwater acoustic OFDM time-varying channel estimation method based on sparse Bayesian learning, belonging to the field of underwater acoustic communication. Background technique [0002] The ocean occupies most of the total surface area of ​​the earth, and the vast ocean contains a large amount of untapped wealth. The development of ocean resources is inseparable from the support of underwater communication technology. In recent years, Orthogonal Frequency Division Multiplexing (OFDM) technology has been widely used in underwater communication systems because of its high spectrum efficiency and anti-frequency selective fading characteristics. However, the underwater acoustic channel has serious noise interference and severely limited bandwidth. It is a time-varying and frequency-varying fading channel. For OFDM systems, how to accurately ...

AI Technical Summary

Problems solved by technology

However, the underwater acoustic channel has serious noise interference and severely limited bandwidth. It is a time-varying and frequency-varying fading channel. For OFDM systems, how to accurately estimate the underwater acoustic channel is still a research hotspot.

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