Adaptive Modulation Control System and Wireless Communication Apparatus

An adaptive modulation control system comprising:

• a reception state measuring section that calculates a first reception state determined based on reception power of a signal received from a communicating party, and a second reception state indicated by a ratio or difference between the first reception state and a criterion value;
• a storage section that stores propagation path information indicative of a measurement result of a propagation path state;
• a transmission-time propagation path estimating section that estimates a transmission-time propagation path state that is a propagation path state of the transmission time based on current propagation path information and one or a plurality of pieces of previous propagation path information stored in the storage section;
• a correcting section that makes a correction of at lease one of changing the transmission-time propagation path state to make the transmission-time propagation path state poorer as the first or the second reception state is higher, and of changing the transmission-time propagation path state to make the transmission-time propagation path state better as the first or the second reception state is lower, based on the first or the second reception state;
• and
• a modulation parameter selecting section that selects a modulation parameter corresponding to the corrected transmission-time propagation path state.

An adaptive modulation control system comprising:

• a reception state measuring section that calculates a first reception state determined based on reception power of a signal received from a communicating party, and a second reception state indicated by a ratio or difference between the first reception state and a criterion value;
• a correcting section that makes a correction to a relational expression between a propagation path state and a modulation parameter or a table comprised of propagation path states and modulation parameters by performing at least one of changing the relational expression with the modulation parameter or the table comprised of propagation path states and modulation parameters so that a modulation parameter with a lower transmission rate is easier to select in the same propagation path conditions as the first or the second reception state is higher, and of changing the relational expression with the modulation parameter or the table comprised of propagation path states and modulation parameters so that a modulation parameter with a higher transmission rate is easier to select in the same propagation path conditions as the first or the second reception state is lower;
• and
• a modulation parameter selecting section that selects a modulation parameter corresponding to propagation path information indicative of a measurement result of the propagation path state based on the corrected relational expression or table.

An adaptive modulation control system comprising:

• a reception state measuring section that calculates a first reception state determined based on reception power of a signal received from a communicating party, and a second reception state indicated by a ratio or difference between the first reception state and a criterion value;
• a storage section that stores propagation path information indicative of a measurement result of a propagation path state;
• a transmission-time propagation path estimating section that estimates a transmission-time propagation path state that is a propagation path state of the transmission time based on current propagation path information and one or a plurality of pieces of previous propagation path information stored in the storage section;
• a correcting section that makes a correction to a relational expression between the propagation path state and a modulation parameter or a table comprised of propagation path states and modulation parameters by performing at least one of changing the relational expression with the modulation parameter or the table comprised of propagation path states and modulation parameters so that a modulation parameter with a lower transmission rate is easier to select in the same propagation path conditions as the first or the second reception state is higher, and of changing the relational expression with the modulation parameter or the table comprised of propagation path states and modulation parameters so that a modulation parameter with a higher transmission rate is easier to select in the same propagation path conditions as the first or the second reception state is lower;
• and
• a modulation parameter selecting section that selects a modulation parameter corresponding to the transmission-time propagation path state based on the corrected relational expression or table.