Patents by Inventor Ashraf A. Tahat

Ashraf A. Tahat has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7385617
    Abstract: A system and method of channel estimation for a multi-user broadband wireless channel estimation in multiple antenna receiver systems use a specifically selected delay in the pilot symbol sequence portion of the transmission which is a multiple of the minimum Cyclic Prefix delay length. This insures that the time-frequency slot information bursts will always be separated in the time domain. A matched filter output in the receiver is formed by multiplying each pilot symbol by the conjugate of the training symbols of the first user. Estimation of the channel response may include three different versions of the efficient estimation calculations, namely Constrained Inverse Deconvolution, Iterative Low Complexity, and Extrapolated Matched Filter estimations. The first two methods do not require matrix multiplication (using only Fourier transforms), while the third method utilizes a smaller matrix multiplication than previously taught.
    Type: Grant
    Filed: May 7, 2003
    Date of Patent: June 10, 2008
    Assignee: Illinois Institute of Technology
    Inventor: Ashraf A. Tahat
  • Publication number: 20040223561
    Abstract: A system and method of channel estimation for a multi-user broadband wireless channel estimation in multiple antenna receiver systems use a specifically selected delay in the pilot symbol sequence portion of the transmission which is a multiple of the minimum Cyclic Prefix delay length. This insures that the time-frequency slot information bursts will always be separated in the time domain. A matched filter output in the receiver is formed by multiplying each pilot symbol by the conjugate of the training symbols of the first user. Estimation of the channel response may include three different versions of the efficient estimation calculations, namely Constrained Inverse Deconvolution, Iterative Low Complexity, and Extrapolated Matched Filter estimations. The first two methods do not require matrix multiplication (using only Fourier transforms), while the third method utilizes a smaller matrix multiplication than previously taught.
    Type: Application
    Filed: May 7, 2003
    Publication date: November 11, 2004
    Inventor: Ashraf A. Tahat