Title:
複数の通信システムのための基準信号生成
Document Type and Number:
Japanese Patent JP4955769
Kind Code:
B2
Abstract:
Techniques for generating reference signals for multiple communication systems are described. An apparatus comprises a reference oscillator, a frequency control unit, and a plurality of frequency synthesizers. The reference oscillator generates a main reference signal and may be a crystal oscillator or some other type of oscillator. The frequency control unit estimates the frequency error of the main reference signal and provides a frequency error estimate. The plurality of frequency synthesizers receive the main reference signal and generate a plurality of system reference signals for a plurality of systems. At least one (e.g., each) frequency synthesizer corrects the frequency error of the main reference signal based on the frequency error estimate from the frequency control unit. Each frequency synthesizer may include a sigma-delta modulator used to generate a divider control for a phase locked loop (PLL). The divider control corrects for the frequency error of the main reference signal.
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Inventors:
Harms, Brian Kay.
Application Number:
JP2009523945A
Publication Date:
June 20, 2012
Filing Date:
August 07, 2007
Export Citation:
Assignee:
QUALCOMM INCORPORATED
International Classes:
H03L7/197; H03L1/02; H03L7/183
Domestic Patent References:
| JP2003069426A | ||||
| JP2001014057A |
Foreign References:
| EP1206039A2 | ||||
| US5604468 | ||||
| EP1213830A1 | ||||
| US20020010010 |
Attorney, Agent or Firm:
Kurata Masatoshi
Satoshi Kono
Makoto Nakamura
Yoshihiro Fukuhara
Takashi Mine
Toshio Shirane
Sadao Muramatsu
Nobuhisa Nogawa
Kocho Chojiro
Naoki Kono
Katsu Sunagawa
Tetsuya Kazama
Katsumura Hiro
Shoji Kawai
Tatsushi Sato
Takashi Okada
Mihoko Horiuchi
Takenori Masanori
Takuzo Ichihara
Yamashita Gen
Satoshi Kono
Makoto Nakamura
Yoshihiro Fukuhara
Takashi Mine
Toshio Shirane
Sadao Muramatsu
Nobuhisa Nogawa
Kocho Chojiro
Naoki Kono
Katsu Sunagawa
Tetsuya Kazama
Katsumura Hiro
Shoji Kawai
Tatsushi Sato
Takashi Okada
Mihoko Horiuchi
Takenori Masanori
Takuzo Ichihara
Yamashita Gen