The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 26, 1998
Filed:
Mar. 22, 1996
Ichiro Tsujimoto, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
In a time diversity radio communications system, quadrature-modulated spread spectrum signals of different mutual time delay are combined into a code division multiplex signal and up-converted to a radio-frequency signal and transmitted. At a receive site, the signal is received by an antenna and down-converted to recover the code division multiplex signal. Quadrature-modulated component signals contained in the recovered code division multiplex signal are converted to baseband signals which are then time-aligned with each other. The time-aligned baseband signals are multiplied respectively by complex weighting factors and are combined together to produce an input signal for an adaptive equalizer. This input signal is also applied to an AGC amplifier where it is amplified and applied to correlation detectors where correlations between the amplified signal and the baseband signals are detected and the complex weighting factors are derived respectively from the correlations. In a modified embodiment, the quadrature-modulated component signals are fed into an adaptive RAKE matched filter where the output of the AGC amplifier is used for detecting the correlations.