Title:
BPSK DEMODULATOR
Document Type and Number:
Japanese Patent JP3642230
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a small-sized information terminal by simplifying hardware for applying BPSK processing to a reader/writer for a contactless IC card and a radio tag.
SOLUTION: A preamplifier amplifies a received signal that is received from an antenna and BPSK-modulated, the amplified signal passes through a filter that eliminates the carrier from the signal to extract only a required signal, a comparator measures a time from the rise of a threshold processed waveform until a succeeding rise to detect the wavelength and a parts of a change in the wavelength are detected as phase change points shown in Figure 5 to conduct BPSK demodulation. Thus, a BPSK demodulation circuit having been executed by hardware conventionally is eliminated and software covers the BPSK demodulation circuit, then a small-sized information terminal requiring BPSK demodulation can be provided.
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Inventors:
Osamu Kobayashi
Shiro Suzuki
Naoki Hatada
Kosuke Watanabe
Shiro Suzuki
Naoki Hatada
Kosuke Watanabe
Application Number:
JP14284299A
Publication Date:
April 27, 2005
Filing Date:
May 24, 1999
Export Citation:
Assignee:
Matsushita Electric Industrial Co., Ltd
International Classes:
H04L27/22; (IPC1-7): H04L27/22
Domestic Patent References:
| JP326133A | ||||
| JP10233718A | ||||
| JP2279050A | ||||
| JP11355369A | ||||
| JP9181783A |
Attorney, Agent or Firm:
Fumio Iwahashi
Tomoyasu Sakaguchi
Hiroki Naito
Tomoyasu Sakaguchi
Hiroki Naito
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