RADIO RECEIVER AND RADIO SIGNAL PROCESSING METHOD

• US 20070224960A1
• Filed: 05/18/2007
• Published: 09/27/2007
• Est. Priority Date: 04/25/2003
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: TOYODA, Takehiko, YOSHIDA, Hiroshi, SETO, Ichiro, SEKIGUCHI, Takahiro
• Application Number:
  US11/750,598
• Publication Number:
  US 20070224960A1
• Time in Patent Office: Days
• US Class Current: 455/245.100
• CPC Class Codes: H03D 3/008 Compensating DC offsets
• CPC Class Codes: H03G 3/3068 Circuits generating control signals for both R.F. and I.F. stages
• CPC Class Codes: H04B 1/30 for homodyne or synchrodyne receivers demodulator circuits H03D1/22
• CPC Class Codes: H04L 27/3809 Amplitude regulation arrangements

Abstract

A radio receiver comprises a first amplifier to amplify a received radio signal; a quadrature demodulator to demodulate the radio signal amplified by said first amplifier and thereby generate a baseband signal; a second amplifier to amplify the baseband signal; a demodulator to demodulate the baseband signal amplified by said second amplifier; and a gain controller to control timing of a change in a gain of said second amplifier, in case that changing the gain of said first amplifier and the gain of said second amplifier, on the basis of a gain of said first amplifier before and after the change.

Claims

1-20. -20. (canceled)

21. A radio signal processing method in a radio receiver, the radio receiver comprising a first amplifier, a second amplifier and a gain controller controlling gains of the first and the second amplifier, the method comprising:

receiving a radio signal;

amplifying a received radio signal in the first amplifier;

demodulating the amplified radio signal to a baseband signal;

amplifying the baseband signal in the second amplifier;

demodulating the amplified baseband signal;

controlling timing, in the gain controller, of a change in a gain of the first amplifier, in case that the gain of the first amplifier and the gain of the second amplifier are changed, on the basis of a gain of the first amplifier before and after the change;

detecting strength of the baseband signal;

selecting the gain of the first amplifier and the gain of the second amplifier at the gain controller on the basis of the strength of the baseband signal;

comparing actual gains of the first amplifier and the second amplifier with the selected gain of the first amplifier and the selected gain of the second amplifier;

determining timing of a change in the gain of the second amplifier on the basis of a result of the comparison;

generating a control signal to change the gain of the first amplifier and the gain of the second amplifier; and

transmitting the control signal to the second amplifier in accordance with the determined timing.

22. The method according to claim 21, wherein

in a case that said gain controller changes the gain of said first amplifier from a high gain to a low gain and changes the gain of said second amplifier from a low gain to a high gain,

the gain controller transmits the control signal to said second amplifier a delay after transmission of the control signal to said first amplifier.

23. The radio receiver according to claim 21, wherein a delay time is shorter than a repetition period of the changes in the gain of said first amplifier and the gain of said second amplifier, said delay time being a period from the change in the gain of said first amplifier until the change in the gain of said second amplifier.

24. A method of processing a radio signal in a radio receiver, the radio receiver comprising a first amplifier, a second amplifier and a gain controller controlling a gain of the first and the second amplifier, the method comprising:

receiving a radio signal;

amplifying a received radio signal in the first amplifier;

demodulating the amplified radio signal to a baseband signal;

amplifying the baseband signal in the second amplifier, after changing a gain of said first amplifier, with a gain based on a gain of said first amplifier obtained before and after the change; and

demodulating the amplified baseband signal, wherein

in a case that the gain of said first amplifier is changed from a high gain to a low gain and the gain of said second amplifier is changed from a low gain to a high gain, timing of the change in the gain of said second amplifier is delayed as compared with timing of the change in the gain of said first amplifier.

25. The method according to claim 24, wherein a delay time is shorter than a repetition period of the changes in the gain of said first amplifier and the gain of said second amplifier, said delay time being a period from the change in the gain of said first amplifier until the change in the gain of said second amplifier.

26. A radio signal processing method comprising:

receiving a radio signal;

amplifying the radio signal;

demodulating the amplified radio signal to a baseband signal;

amplifying the baseband signal;

demodulating the amplified baseband signal;

determining timing of a change in a gain of the radio signal amplification and a gain of the baseband signal amplification, in case that the gain in the radio signal amplification and the gain in the baseband signal amplification are changed, on the basis of the gain in the radio signal amplification obtained before and after the change; and

changing the gain in the radio signal amplification and the gain in the baseband signal amplification in accordance with the determined timing,

wherein in a case where the gain in the radio signal amplification is changed from a high gain to a low gain and the gain in the baseband signal amplification is changed from a low gain to a high gain, in a case that the timing of the change in the gain is determined, the gain in the baseband signal amplification is changed with a delay to the change in the gain in the radio signal amplification.