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:
Sep. 02, 2003
Filed:
Dec. 18, 2001
Hyun Kyu Yu, Taejon, KR;
Seon-Ho Han, Wonju-Shi, KR;
Mun Yang Park, Taejon, KR;
Seong-Do Kim, Taejon, KR;
Yong-Sik Youn, Taejon, KR;
Lee-Sup Kim, Taejon, KR;
Ki-Hyuk Sung, Taejon, KR;
Byung-Do Yang, Seoul, KR;
Young-Jun Kim, Yongin-Shi, KR;
Abstract
The present invention relates to a ROM division method for reducing the size of a ROM in a direct digital frequency synthesizer (DDFS), which is used to synthesize a frequency in a communication system requiring fast frequency conversion. A ROM consuming most energy in the system, a modified Nicholas architecture is brought forth to reduce the size of ROM. In this modified Nicholas architecture, a ROM is divided into coarse ROM and fine ROM to convert phase to sine value. The present invention divides the coarse ROM and the fine ROM into quantized ROM and error ROM respectively. Then, value stored in each ROM is segmented in certain intervals and the minimum quantized value in each of the section is stored in the quantized ROM, while the difference between the original ROM value and the quantized ROM value is stored in the error ROM. This way, the size of a ROM can be reduced. Phase value inputted in a DDFS, a sine value is calculated by adding the four ROM values, i.e., coarse-quantized ROM, coarse-error ROM, fine-quantized ROM and fine-error ROM.