Blind Equalization and Channel Estimation in Coherent Optical Communications Using Variational Autoencoders

Blind Channel Equalization using Variational Autoencoders

A new maximum likelihood estimation approach for blind channel equalization, using variational autoencoders (VAEs), is introduced. Significant and consistent improvements in the error rate of the reconstructed symbols, compared to constant modulus equalizers, are demonstrated. In fact, for the channels that were examined, the performance of the new VAE blind channel equalizer was close to the p...

Blind Equalization Using Direct Channel Estimation

In performing blind equalization, we propose a direct channel estimation method based on entropy-maximization of input signal with its known probability density function. That is, the proposed method estimates filter coefficients of the channel instead of equalizing filter coefficients which most of equalization methods try to estimate. Because the channel usually has a much shorter length than...

Blind Equalization with Generalized Inverse Channel Estimation and Fractional Phase MLSE Metrics for Mobile Communications

This paper proposes a new blind adaptive MLSE equalizer for frequency selective mobile radio channels. The proposed equalizer performs channel estimation for each survivor path of the Viterbi algorithm (VA), and restricts the number of symbol candidates for the channel estimation in order to reduce prohibitive complexity. In such channel estimation, autocorrelation matrices of the symbol candid...

Frequency-Domain Equalization and Channel Estimation for Broadband Wireless Communications

New services such as high-speed data transmission and multimedia applications have tremendously increased the bandwidth requirements for communications in the last two decades. On the other hand, the emerging need for access to information everywhere at every time (ubiquity) has focused attention over wireless communications. At the physical layer, wireless broadband transmission is characteriz...

Blind equalization for underwater communications