InterDigital Inc (IDCC)

[Gamco]

United States Patent 7,599,668
Ozluturk , et al. October 6, 2009
Method and apparatus for reducing antenna correlation

Abstract
The present invention is related to a method and apparatus for reducing antenna correlation between multiple antennas. A transmitter generates at least two beams with a plurality of antennas. The generated beams are spatially separated to point away each other. Therefore, the transmitted signals travel through different channel conditions and arrive at a receiver mutually uncorrelated. The beams may be generated by antennas having different antenna pattern, or by an array antenna. The beams may be polarized differently. The schemes may be implemented on a subcarrier basis in an orthogonal frequency division multiplexing (OFDM) system. Trellis coded mapping may be utilized for adjacent symbols to be mapped to antennas with low correlation.

Inventors: Ozluturk; Fatih (Port Washington, NY), Pietraski; Philip J. (Huntington Station, NY)
Assignee: InterDigital Technology Corporation (Wilmington, DE)
Appl. No.: 11/202,570
Filed: August 12, 2005
Related U.S. Patent Documents
Application Number Filing Date Patent Number Issue Date
60601674 Aug., 2004
Current U.S. Class: 455/101 ; 455/107; 455/121; 455/562.1
Current International Class: H04B 1/02 (20060101)
Field of Search: 455/101,277.1,562.1,67.16,121,107 375/347