Automatic gain control method for radio communication mobile station

• US 20050053175A1
• Filed: 09/03/2004
• Published: 03/10/2005
• Est. Priority Date: 09/05/2003
• Status: Active Grant

• Current Assignee: Lenovo Innovations Ltd Hong Kong (Lenovo Group Ltd.)
• Original Assignee: NEC Corporation
• Inventors: Furuya, Tomoki
• Granted Patent: US 7,596,192 B2
• Time in Patent Office: Days
• US Class Current: 375/345
• CPC Class Codes: H03D 3/007 by converting the oscillations into two quadrature related signals H03D3/245 takes precedence

Abstract

A signal transmitted from a base station is received by a receiver. The received signal is supplied to an AGC amplifier and is then supplied to a demodulator, so that the signal is demodulated into baseband signals. The baseband signals are supplied to a baseband signal processor. The baseband signals are also processed through an instantaneous received power calculator, an average received power calculator, and a feedback AGC code generator to produce an AGC signal. The gain of the AGC amplifier is controlled based on the AGC signal. A fading pitch measuring device measures a fading pitch from the instantaneous power calculated by the instantaneous received power calculator. The average received power calculator changes averaging time required to calculate average received power depending on the measured fading pitch.

Claims

1. An automatic gain control method for a radio communication mobile station, the method comprising the steps of:

measuring a fading pitch on the basis of the received power of a signal received by the radio communication mobile station; and

changing averaging time required to calculate average received power used in automatic gain control depending on the fading pitch.

2. An automatic gain control method for a radio communication mobile station, the method comprising the steps of:

receiving fading pitch information transmitted from a base station; and

changing averaging time required to calculate average received power used in automatic gain control depending on the fading pitch information.

3. A radio communication mobile station comprising:

means for receiving a signal transmitted from a base station;

variable gain amplifying means for amplifying the received signal;

demodulating means for demodulating the amplified signal into baseband signals;

instantaneous received power calculating means for calculating instantaneous received power from the baseband signals;

fading pitch measuring means for measuring a fading pitch from the instantaneous received power calculated by the instantaneous received power calculating means;

average received power calculating means for calculating average received power from the instantaneous received power calculated by the instantaneous received power calculating means; and

automatic gain control (AGC) signal generating means for generating an AGC signal to control the gain of the variable gain amplifying means on the basis of the average received power calculated by the average received power calculating means, wherein

the average received power calculating means includes means for changing averaging time required to calculate the average received power according to information related to the fading pitch measured by the fading pitch measuring means.

4. A radio communication mobile station comprising:

means for receiving a signal transmitted from a base station;

variable gain amplifying means for amplifying the received signal;

demodulating means for demodulating the amplified signal into baseband signals;

baseband signal processing means for processing the baseband signals generated from the demodulating means and extracting fading pitch information included in the received signal from the base station;

instantaneous received power calculating means for calculating instantaneous received power from the baseband signals;

average received power calculating means for calculating average received power from the instantaneous received power calculated by the instantaneous received power calculating means; and

automatic gain control (AGC) signal generating means for generating an AGC signal to control the gain of the variable gain amplifying means on the basis of the average received power calculated by the average received power calculating means, wherein

the average received power calculating means includes means for changing averaging time required to calculate the average received power according to the fading pitch information extracted by the baseband signal processing means.

5. A radio communication mobile station comprising:

an antenna for receiving a signal transmitted from a base station;

a receiver for converting the received signal having a radio frequency bandwidth into an intermediate frequency signal;

an automatic gain control (AGC) amplifier for amplifying the intermediate frequency signal;

an orthogonal demodulator for performing orthogonal demodulation and frequency conversion to the intermediate frequency signal generated from the AGC amplifier to produce I-component and Q-component baseband signals;

AD converters for converting the I-component and Q-component baseband signals, that are analog, generated from the orthogonal demodulator into digital signals, respectively;

a baseband signal processor for processing the digital signals generated from the AD converters;

an instantaneous received power calculator for calculating instantaneous power from the digital signals generated by the AD converters;

a fading pitch measuring device for measuring a fading pitch from the instantaneous power calculated by the instantaneous received power calculator;

an average received power calculator, which receives the instantaneous power calculated by the instantaneous received power calculator and information related to the fading pitch measured by the fading pitch measuring device, for calculating the average received power from the instantaneous power calculated by the instantaneous received power calculator according to averaging time set depending on the fading pitch; and

a feedback AGC code generator for calculating a signal to control the gain of the AGC amplifier so as to offset the difference between reference power and the average received power calculated by the average received power calculator and then feeding back the signal as an AGC signal to the AGC amplifier.

6. A radio communication mobile station comprising:

an antenna for receiving a signal transmitted from a base station;

a receiver for converting the received signal having a radio frequency bandwidth into an intermediate frequency signal;

an automatic gain control (AGC) amplifier for amplifying the intermediate frequency signal;

an orthogonal demodulator for performing orthogonal demodulation and frequency conversion to the intermediate frequency signal generated from the AGC amplifier to produce I-component and Q-component baseband signals;

AD converters for converting the I-component and Q-component baseband signals, that are analog, generated from the orthogonal demodulator into digital signals, respectively;

a baseband signal processor for processing the digital signals generated from the AD converters and extracting fading pitch information included in the received signal transmitted from the base station;

an instantaneous received power calculator for calculating instantaneous power from the digital signals generated from the AD converters;

an average received power calculator, which receives the instantaneous power calculated by the instantaneous received power calculator and the fading pitch information extracted by the baseband signal processor, for calculating average received power from the instantaneous power calculated by the instantaneous received power calculator according to averaging time set depending on the fading pitch information; and

a feedback AGC code generator for calculating a signal to control the gain of the AGC amplifier so as to offset the difference between reference power and the average received power calculated by the average received power calculator and then feeding back the signal as an AGC signal to the AGC amplifier.