Methods and apparatus for blind channel estimation based upon speech correlation structure

An apparatus for blind channel estimation of a speech signal corrupted by a communication channel, said apparatus configured to:

• convert a noisy speech signal into a representation of the noisy speech signal selected from the group consisting of a cepstral representation and a log-spectral representation;
• estimate a correlation of the representation of the noisy speech signal;
• determine an average of the noisy speech signal;
• construct and solve, subject to a minimization constraint, a system of linear equations utilizing a correlation structure of a clean speech training signal, the correlation of the representation of the noisy speech signal, and the average of the noisy speech signal;
• and
• select a sign of the solution of the system of linear equations to estimate an average clean speech signal over a processing time window.

A machine readable medium or media having recorded thereon instructions configured to instruct an apparatus comprising at least one member of the group consisting of a programmable processor and a digital signal processor to:

• convert a noisy speech signal into a representation of the noisy speech signal selected from the group consisting of a cepstral representation and a log-spectral representation;
• estimate a correlation of the representation of the noisy speech signal;
• determine an average of the noisy speech signal;
• construct and solve, subject to a minimization constraint, a system of linear equations utilizing a correlation structure of a clean speech training signal, the correlation of the representation of the noisy speech signal, and the average of the noisy speech signal;
• and
• select a sign of the solution of the system of linear equations to estimate an average clean speech signal in a processing time window.