Study on EFEC is mainly applied to the optical communication which time delay is not requested strictly and the coding plus should be very high.

This technique uses different time delay values of the LFM pulse to code the transmitted information, and uses time delay estimation technique to perform decoding.

By the convergence of the method, we can fast construct a COSTBC matrix with the maximal rates and the minimal decoding delays that we all know now recur to the computer.