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. 23, 2000
Filed:
Sep. 03, 1997
Gregory Clark Copeland, San Jose, CA (US);
Integrated Device Technology, Inc., Santa Clara, CA (US);
Abstract
A method and apparatus for equalizing a received quadrature amplitude modulated signal is disclosed. To equalize the signal, a band edge equalizer (BEE) is used in combination with a symbol spaced equalizer (SSE) and possibly a decision feedback equalizer (DFE). The equalizer's are used along a series path to equalize the QAM signal in a series of equalization operations. By separating the equalization of the signal to separate equalizers, the cost of the equalization can be reduced without substantially affecting performance. In particular, band edge equalizing the QAM signal and symbol space equalizing the symbol can reduce the number of multiplies per second required by any particular equalizer. Accordingly, the equalizers used can be less expensive. Also, using a decimating circuit between the BEE and the SSE that decimates the sample rate of the signal being provided to the SSE can further reduce the number of multiplies per second that must be performed by the SSE. Clock recovery and synchronization circuits have also been disclosed.