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:
Jul. 07, 1998
Filed:
Nov. 24, 1995
Thomas Ostman, Sp.ang.nga, SE;
Anders Engman, Stockholm, SE;
Telefonaktiebolaget LM Ericsson, Stockholm, SE;
Abstract
Methods and systems for determining a cosine (I) or sine (Q) component for the purpose of modulating a digital signal in radiocommunication systems are disclosed. Exemplary embodiments describe how such determinations may be performed using digital signal processing techniques to improve component accuracy, while reducing the amount of processor memory (e.g., DSP memory) used to accomplish this task. Phase information from a sampled signal is used to access one or more tables containing component values, or a combination of a component base values and difference values between consecutive base values. The phase information can be used derive an offset value from the difference values, which offset value is added to a component base value to provide a component value for output. This has the effect of reducing the amount of memory consumed while maintaining high resolution.