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. 27, 2003
Filed:
Aug. 10, 1999
Takayuki Shibata, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
In a receiving device, a mixer combines a frequency which is different from a carrier frequency by (2n+½)&ohgr; and a reception signal, provided that n is an integer, &ohgr; =2Π/T, and T is a transmission rate of a base band signal, a filter takes out a base band signal of a center frequency of (2n+½)&ohgr; and removes a DC component, so as to sample the signal and put it through A/D conversion, a multiplier combines the signal and a polarity signal, so as to obtain an in-phase component p(nT) of the reception signal at time nT and an orthogonal component q[(n+½)T] of the reception signal at time (n+½)T. A branch metric is calculated and maximum likelihood sequence estimation is executed on the basis of those components and a replica signals pR(nT) and qR[(n+½)T], so as to estimate a signal sequence. Thus the receiving device exhibits improved performance as it is capable of eliminating any phase difference and amplitude difference between Ich and Qch and any DC offset, without requiring any large-scale additional circuit.