**Matrix Expansions for Computing the
Discrete Hartley Transform **

** **

A new fast algorithm for computing the discrete Hartley transform (DHT) is presented, which is based on the expansion of the transform matrix. The algorithm presents a better performance, in terms of multiplicative complexity, than previously known fast Hartley transform algorithms. A detailed description of the computation of DHTs with blocklengths 8 and 12 is shown. The algorithm is very attractive for blocklengths N ≥ 128.