A novel scheme to joint phase noise (PHN) correcting and channel noise variance estimating for orthogonal frequency division multiplexing (OFDM) signal was proposed. The new scheme was based on the variational Bayes (VB) method and discrete cosine transform (DCT) approximation. Compared with the least squares (LS) based scheme, the proposed scheme could overcome the over-fitting phenomenon and thus lead to an improved performance. Computer simulations showed that the proposed VB based scheme outperforms the existing LS based scheme A novel scheme to joint phase noise (PHN) correcting and channel noise variance estimating for orthogonal frequency division multiplexing (OFDM) signal was proposed. The new scheme was based on the variational Bayes (VB) method and discrete cosine transform (DCT) approximation. Compared with the least squares (LS) based scheme, the proposed scheme could overcome the over-fitting phenomenon and thus lead to an improved performance. Computer simulations showed that the proposed VB based scheme outperforms the existing LS based scheme