Title:
【発明の名称】フィルタに遮断周波数切替手段を備えた直接変換受信機
Document Type and Number:
Japanese Patent JP3073687
Kind Code:
B2
Abstract:
A direct conversion receiver has: an I-low-pass filter 9 which has cut-off frequency switching device, switches over the cut-off frequency in accordance with the transmission rate, and eliminates high-frequency components from a modulated signal mixed with a first local signal; a Q-low-pass filter 10 which eliminates high-frequency components from a modulated signal mixed with the first local signal phase-shifted by 90 degrees; transmission rate detecting device 13 for detecting transmission rate information from transmission data detected by transmission data detecting device 12; and I- and Q-low-pass filter cut-off frequency controlling device 15 and 16 for generating I- and Q-control signals which control the cut-off frequency switching device, from the detected transmission rate. The cut-off frequencies of the low-pass filters are switched over in accordance with the transmission rate of reception.
Inventors:
Hiroshi Katayama
Homi Imagawa
Masahiro Mimura
Homi Imagawa
Masahiro Mimura
Application Number:
JP4686596A
Publication Date:
August 07, 2000
Filing Date:
February 09, 1996
Export Citation:
Assignee:
Matsushita Electric Industrial Co., Ltd
International Classes:
H04L27/148; H04B1/16; H04B7/26; H04L27/14; H04L27/227; H04W4/00; H04W88/00; H04W88/02; H04L27/00; (IPC1-7): H04L27/14; H04B7/26
Domestic Patent References:
| JP575411A | ||||
| JP6104947A | ||||
| JP5244576A | ||||
| JP10511525A |
Other References:
電子情報通信学会技術研究報告ＣＳ８９ ｐ．１５−２０「伝送レート可変ディジタル変調器」
Attorney, Agent or Firm:
Isao Saito