Receiving apparatus, and computer readable memory medium that stores a program

A receiving apparatus comprising:

• a first amplifier that amplifies a received wave using high frequency;
• a frequency converter that performs frequency conversion on a signal output from the first amplifier from a frequency band of the first amplifier to a frequency band at a later stage;
• an analog filter that filters the signal that has been subjected to frequency conversion by the frequency converter;
• a second amplifier that amplifies the signal, which was filtered by the analog filter, using a demodulation frequency;
• a converter that converts the output signal from the second amplifier to a digital signal;
• a digital filter that filters the digital signal output from the converter to a desired frequency band;
• a demodulator that demodulates the digital signal that was filtered by the digital filter;
• and
• a digital circuit to which the digital signal output from the converter before being filtered by the digital filter and the digital signal that was output from the converter and then filtered by the digital filter are inputted;
• wherein the digital circuit comprises:
• a power difference calculation unit that calculates a power difference between the digital signal output from the converter before being filtered by the digital filter and the digital signal that was output from the converter and then filtered by the digital filter;
• and
• a gain control unit that, based on at least the power difference that was calculated by the power difference calculation unit, controls a gain ratio of the first amplifier and the second amplifier,
• wherein the digital circuit further comprises a gain reference value setting unit that, based on a signal power of the digital signal output from the converter before being filtered by the digital filter, or a signal power of the digital signal that was output from the converter and then filtered by the digital filter, outputs a reference value for setting a total gain value of the first amplifier and the second amplifier;
• wherein the gain control unit sets the total gain value of the first amplifier and second amplifier based on the reference value, and sets the gain ratio based on the power difference and the total gain value.

A receiving apparatus comprising:

• a first amplifier that amplifies a received wave using high frequency;
• a frequency converter that performs frequency conversion on a signal output from the first amplifier from a frequency band of the first amplifier to a frequency band at a later stage;
• an analog filter that filters the signal that has been subjected to frequency conversion by the frequency converter;
• a second amplifier that amplifies the signal, which was filtered by the analog filter, using a demodulation frequency;
• a converter that converts the output signal from the second amplifier to a digital signal;
• a digital filter that filters the digital signal output from the converter to a desired frequency band;
• a demodulator that demodulates the digital signal that was filtered by the digital filter;
• and
• a digital circuit to which the digital signal output from the converter before being filtered by the digital filter and the digital signal that was output from the converter and then filtered by the digital filter are inputted;
• wherein the digital circuit comprises:
• a power difference calculation unit that calculates a power difference between the digital signal output from the converter before being filtered by the digital filter and the digital signal that was output from the converter and then filtered by the digital filter;
• and
• a gain control unit that, based on at least the power difference that was calculated by the power difference calculation unit, controls a gain ratio of the first amplifier and the second amplifier,
• wherein the gain control unit periodically performs control of the gain ratio, and performs control of the first amplifier for a longer period than control of the second amplifier.

A non-transitory computer readable memory medium on which a program is recorded that is executable by a computer, which controls a receiving apparatus, wherein the receiving apparatus comprises:

• a first amplifier that amplifies a received wave using high frequency;
• a frequency converter that performs frequency conversion on a signal output from the first amplifier from a frequency band of the first amplifier to a frequency band at a later stage;
• an analog filter that filters the signal that has been subjected to frequency conversion by the frequency converter;
• a second amplifier that amplifies the signal, which was filtered by the analog filter, using a demodulation frequency;
• a converter that converts the output signal from the second amplifier to a digital signal;
• a digital filter that filters the digital signal output from the converter to a desired frequency band;
• and
• a demodulator that demodulates the digital signal that was filtered by the digital filter, and
• wherein the program is executable by the computer to control the receiving apparatus to perform functions comprising:
• calculating a power difference between the digital signal output from the converter before being filtered by the digital filter and the digital signal that was output from the converter and then filtered by the digital filter;
• controlling a gain ratio of the first amplifier and the second amplifier based on at least the calculated power difference;
• outputting a reference value for setting a total gain value of the first amplifier and the second amplifier based on a signal power of the digital signal output from the converter before being filtered by the digital filter, or a signal power of the digital signal that was output from the converter and then filtered by the digital filter;
• setting the total gain value of the first amplifier and second amplifier based on the reference value;
• estimating a power of a received signal in the desired frequency band based on the power difference and the reference value;
• determining a quality of the received signal based on a demodulation result of the demodulator;
• detecting a status of a propagation path based on the demodulation result of the demodulator;
• setting the gain ratio based on an additional condition including at least one of the reception power, the quality of the received signal, and the status of the propagation path;
• and
• controlling a polarity of the output frequency from the frequency converter and the analog filter based on at least one of the reception power, the quality of the received signal, and the status of the propagation path.

A receiving method for a receiving apparatus, the method comprising:

• amplifying, with a first amplifier, a received wave using high frequency;
• performing, with a frequency converter, frequency conversion on a signal output from the first amplifier from a frequency band of the first amplifier to a frequency band at a later stage;
• filtering, with an analog filter, the signal that has been subjected to frequency conversion by the frequency converter;
• amplifying, with a second amplifier, the signal which was filtered by the analog filter, using a demodulation frequency;
• converting, with a converter, the output signal from the second amplifier to a digital signal;
• filtering, with a digital filter, the digital signal output from the converter to a desired frequency band;
• demodulating, with a demodulator, the digital signal that was filtered by the digital filter;
• calculating a power difference between the digital signal output from the converter before being filtered by the digital filter and the digital signal that was output from the converter and then filtered by the digital filter;
• controlling a gain ratio of the first amplifier and the second amplifier, based on at least the calculated power difference;
• outputting a reference value for setting a total gain value of the first amplifier and the second amplifier based on a signal power of the digital signal output from the converter before being filtered by the digital filter, or a signal power of the digital signal that was output from the converter and then filtered by the digital filter;
• setting the total gain value of the first amplifier and second amplifier based on the reference value;
• estimating a power of a received signal in the desired frequency band based on the power difference and the reference value;
• determining a quality of the received signal based on a demodulation result of the demodulator;
• detecting a status of a propagation path based on the demodulation result of the demodulator;
• setting the gain ratio based on an additional condition including at least one of the reception power, the quality of the received signal, and the status of the propagation path;
• and
• controlling a polarity of the output frequency from the frequency converter and the analog filter based on at least one of the reception power, the quality of the received signal, and the status of the propagation path.

A receiving apparatus comprising:

• a first amplifier that amplifies a received wave using high frequency;
• a frequency converter that performs frequency conversion on a signal output from the first amplifier from a frequency band of the first amplifier to a frequency band at a later stage;
• an analog filter that filters the signal that has been subjected to frequency conversion by the frequency converter;
• a second amplifier that amplifies the signal, which was filtered by the analog filter, using a demodulation frequency;
• a converter that converts the output signal from the second amplifier to a digital signal;
• a digital filter that filters the digital signal output from the converter to a desired frequency band;
• a demodulator that demodulates the digital signal that was filtered by the digital filter;
• and
• a digital circuit to which the digital signal output from the converter before being filtered by the digital filter and the digital signal that was output from the converter and then filtered by the digital filter are inputted;
• wherein the digital circuit comprises:
• a gain control unit that controls a gain ratio of the first amplifier and the second amplifier;
• a quality judgment unit that, based on demodulation results of the demodulator, determines a quality of a received signal;
• and
• a status detection unit that, based on the demodulation results of the demodulator, detects a status of a propagation path;
• wherein the gain control unit temporarily changes the gain ratio, and sets the gain ratio based on at least one of a judgment result of the quality judgment unit and a detection result of the status detection unit before and after changing the gain ratio.