Transmission power control apparatus and method in a mobile communication system, mobile station, and communication apparatus

A transmission power control device that controls transmission power of a mobile station based on transmission power control information transmitted from a plurality of base stations to the mobile station in a mobile communication system in which each of the base stations to be radio-connected to the mobile station supplies the mobile station with the transmission power control information that is determined based on reception signal quality,

• the transmission power control device comprising:
• a transmission loss calculator that calculates a transmission loss in an electric wave transmission path between the mobile station and each of the base stations, based on a predetermined signal transmitted from each of the base stations with a fixed transmission power level;
• a fading condition measurer that measures a fading condition of the mobile station;
• a fading condition determiner that determines whether the fading condition of the mobile station measured by the fading condition measurer is better than a predetermined condition;
• and
• a switch controller that validates a first transmission power control information determiner when the fading condition determiner determines that the fading condition of the mobile station is better than the predetermined condition, and validates a second transmission power control information determiner when the fading condition determiner determines that the fading condition of the mobile station is not better than the predetermined condition,
• the first transmission power control information determiner including:
• a weight corrector that performs weighting on the transmission power control information transmitted from each of the base stations to the mobile station, so that a greater weight is given to the transmission power control information transmitted from a base station having a smaller transmission loss in the electric wave transmission path to the mobile station, the weight corrector thus generating weight correction control information;
• and
• a combiner that combines the weight correction control information that is generated from the weight corrector and corresponds to the transmission power control information transmitted from the base stations, the combiner thus generating composite transmission power control information,
• the first transmission power control information determiner determining which transmission power control information is to be used in a transmission power control operation at the mobile station, based on the composite transmission power control information generated from the combiner,
• the second transmission power control information determiner including a selector that selects the transmission power control information transmitted from the base station having the smallest transmission loss in the electric wave transmission path to the mobile station, the selection being made from the transmission power control information transmitted from the base stations to the mobile station,
• the second transmission power control information determiner determining which transmission power control information is to be used in a transmission power control operation at the mobile station, based on the transmission power control information selected by the selector.

A transmission power control device that controls transmission power of a mobile station based on transmission power control information transmitted from a plurality of base stations to the mobile station in a mobile communication system in which each of the base stations to be radio-connected to the mobile station supplies the mobile station with the transmission power control information that is determined based on reception signal quality,

• the transmission power control device comprising:
• a transmission path quality measurer that measures the quality of a transmission path between the mobile station and each of the base stations, based on a predetermined signal transmitted from each of the base stations with a fixed transmission power level, the quality of the transmission path being used for determining to which base station the mobile station is to be radio-connected;
• and
• a transmission power control information determiner that determines which transmission power control information is to be used in a transmission power control operation at the mobile station, based on the transmission power control information transmitted from each of the base stations to the mobile station and the quality of the transmission path between the mobile station and each of the base stations measured by the transmission path quality measurer.

A transmission power control device that controls transmission power of a mobile station based on a soft decision value of transmission power control information transmitted from a plurality of base stations to the mobile station in a mobile communication system in which each of the base stations to be radio-connected to the mobile station supplies the mobile station with the transmission power control information that can contain a first value representing a control status of a power increase and a second value representing a control status of a power decrease that are determined based on reception signal quality,

• the transmission power control device comprising:
• a transmission path quality measurer that measures the quality of a transmission path between the mobile station and each of the base stations, based on a predetermined signal transmitted from each of the base stations with a fixed transmission power level;
• and
• a transmission power control information determiner that determines which transmission power control information is to be used in a transmission power control operation at the mobile station, based on the soft decision value of the transmission power control information transmitted from each of the base stations to the mobile station and the quality of the transmission path between each of the base stations and the mobile station measured by the transmission path quality measurer,
• the transmission power control information determiner including:
• a weight corrector that performs weighting on the soft decision value of the transmission power control information transmitted from each of the base stations to the mobile station, so that a greater weight is given to the transmission power control information of a base station having a higher quality in the transmission path to the mobile station, the weight corrector thus generating weight correction control information;
• a combiner that combines the weight correction control information that is generated from the weight corrector and corresponds to the transmission power control information transmitted from the base stations, the combiner thus generating composite transmission power control information;
• and
• a hard decision unit that performs a hard decision on the value of the composite transmission power control information generated from the combiner, using a threshold value that is closer to the first value by a predetermined amount from a middle value between the first value and the second value that can be contained in the transmission power control information transmitted from each of the base stations,
• the transmission power control information determiner determining which transmission power control information is to be used in a transmission power control operation at the mobile station, based on the result of the hard decision.

A transmission power control device that controls transmission power of a mobile station based on a soft decision value of transmission power control information transmitted from a plurality of base stations to the mobile station in a mobile communication system in which each of the base stations to be radio-connected to the mobile station supplies the mobile station with the transmission power control information that can contain a first value representing a control status of a power increase and a second value representing a control status of a power decrease that are determined based on reception signal quality,

• the transmission power control device comprising:
• a transmission path quality measurer that measures the quality of a transmission path between the mobile station and each of the base stations, based on a predetermined signal transmitted from each of the base stations with a fixed transmission power level;
• and
• a transmission power control information determiner that determines which transmission power control information is to be used in a transmission power control operation at the mobile station, based on the soft decision value of the transmission power control information transmitted from each of the base stations to the mobile station and the quality of the transmission path between each of the base stations and the mobile station measured by the transmission path quality measurer,
• the transmission power control information determiner including:
• a weight corrector that performs weighting on the soft decision value of the transmission power control information transmitted from each of the base stations to the mobile station, so that a greater weight is given to the transmission power control information of a base station having a higher quality in the transmission path to the mobile station, the weight corrector thus generating weight correction control information;
• a combiner that combines the weight correction control information that is generated from the weight corrector and corresponds to the transmission power control information transmitted from the base stations, the combiner thus generating composite transmission power control information;
• a first hard decision unit that performs a hard decision on the value of the composite transmission power control information generated from the combiner, using a first threshold value;
• a second hard decision unit that performs a hard decision on the value of the composite transmission power control information, using a second threshold value that is different from the first threshold value;
• and
• a control information generator that generates one of first control information representing a control status of a power increase, second control information representing a control status of a power decrease, or third control information representing a control status of power maintenance, based on a decision result of the first hard decision unit and a decision result of the second hard decision unit,
• the transmission power control information determiner determining that the control information generated from the control information generator is to be used as the transmission power control information in a transmission power control operation at the mobile station.

A transmission power control device that controls transmission power of a mobile station based on transmission power control information transmitted from a plurality of base stations to the mobile station in a mobile communication system in which each of the base stations to be radio-connected to the mobile station supplies the mobile station with the transmission power control information that is determined based on reception signal quality,

• the transmission power control device comprising:
• a transmission path quality measurer that measures the quality of a transmission path between the mobile station and each of the base stations, based on a predetermined signal transmitted from each of the base stations with a fixed transmission power;
• a fading condition measurer that measures a fading condition of the mobile station;
• a fading condition determiner that determines whether the fading condition of the mobile station measured by the fading condition measurer is better than a predetermined fading condition;
• and
• a switch controller that validates a first transmission power control information determiner when the fading condition determiner determines that the fading condition of the mobile station is better than the predetermined condition, and validates a second transmission power control information determiner when the fading condition determiner determines that the fading condition of the mobile station is not better than the predetermined condition,
• the first transmission power control information determiner including:
• a weight corrector that performs weighting on the transmission power control information transmitted from each of the base stations to the mobile station, so that a greater weight is given to the transmission power control information transmitted from a base station having a higher quality in the transmission path to the mobile station, the weight corrector thus generating weight correction control information;
• and
• a combiner that combines the weight correction control information that is generated from the weight corrector and corresponds to the transmission power control information transmitted from the base stations, the combiner thus generating composite transmission power control information,
• the first transmission power control information determiner determining which transmission power control information is to be used in a transmission power control operation at the mobile station, based on the composite transmission power control information generated from the combiner,
• the second transmission power control information determiner including a selector that selects the transmission power control information transmitted from the base station having the highest quality in the transmission path to the mobile station, the selection being made from the transmission power control information transmitted from the base stations to the mobile station, and the transmission path quality having being measured by the transmission path quality measurer,
• the second transmission power control information determiner determining which transmission power control information is to be used in a transmission power control operation at the mobile station, based on the transmission power control information selected by the selector.

A transmission power control method of controlling transmission power of a base station based on transmission power control information transmitted from a plurality of base stations to the mobile station in a mobile communication system in which each of the base stations to be radio-connected to the mobile station supplies the mobile station with the transmission power control information that is determined based on reception signal quality,

• the method comprising the steps of:
• calculating a transmission loss in an electric wave transmission path between the mobile station and each of the base stations, based on a predetermined signal transmitted from each of the base stations with a fixed transmission power level;
• and
• determining which transmission power control information is to be used in a transmission power control operation at the mobile station, based on the transmission power control information transmitted from each of the base stations to the mobile station and the transmission loss in the electric wave transmission path between each of the base stations and the mobile station calculated in the transmission loss calculating step.

A transmission power control method of controlling transmission power of a mobile station based on transmission power control information transmitted from a plurality of base stations to the mobile station in a mobile communication system in which each of the base stations to be radio-connected to the mobile station supplies the mobile station with the transmission power control information that is determined based on reception signal quality,

• the method comprising the steps of:
• calculating a transmission loss in an electric wave transmission path between the mobile station and each of the base stations, based on a predetermined signal transmitted from each of the base stations with a fixed transmission power level;
• measuring a fading condition of the mobile station;
• determining whether the fading condition of the mobile station measured in the fading condition measuring step is better than a predetermined condition;
• and
• performing switch control, validating a first transmission power control information determining step when the fading condition of the mobile station is determined to be better than the predetermined condition in the fading condition determining step, and validating a second transmission power control information determining step when the fading condition of the mobile station is determined not to be better than the predetermined condition in the fading condition determining step,
• the first transmission power control information determining step including the steps of:
• generating weight correction control information, giving such a weight to the transmission power control information transmitted from each of the base stations to the mobile station that a greater weight is given to the transmission power control information transmitted from a base station having a smaller transmission loss in the electric wave transmission path to the mobile station;
• and
• combining the weight correction control information corresponding to the transmission power control information transmitted from the base stations, thereby generating composite transmission power control information, the weight correction control information having been generated in the weight correction control information generating step,
• the first transmission power control information determining step determining which transmission power control information is to be used in a transmission power control operation at the mobile station, based on the composite transmission power control information obtained in the combining step,
• the second transmission power control information determining step including the step of selecting the transmission power control information transmitted from the base station having the smallest transmission loss in the electric wave transmission path to the mobile station calculated in the transmission loss calculating step, the selection being made from the transmission power control information transmitted from the base stations to the mobile station,
• the second transmission power control information determining step determining which transmission power control information is to be used in a transmission power control operation at the mobile station, based on the transmission power control information selected in the selecting step.

A transmission power control method of controlling transmission power of a mobile station based on transmission power control information transmitted from a plurality of base stations to the mobile station in a mobile communication system in which each of the base stations to be radio-connected to the mobile station supplies the mobile station with the transmission power control information that is determined based on reception signal quality,

• the method comprising the steps of:
• measuring the quality of a transmission path between the mobile station and each of the base stations, based on a predetermined signal transmitted from each of the base stations with a fixed transmission power level, the quality of the transmission path being used for determining to which base station the mobile station is to be radio-connected;
• and
• determining which transmission power control information is to be used in a transmission power control operation at the mobile station, based on the transmission power control information transmitted from each of the base stations to the mobile station and the quality of the transmission path between the mobile station and each of the base stations measured in the transmission path quality measuring step.

A transmission power control method of controlling transmission power of a mobile station based on a soft decision value of transmission power control information transmitted from a plurality of base stations to the mobile station in a mobile communication system in which each of the base stations to be radio-connected to the mobile station supplies the mobile station with the transmission power control information that can contain a first value representing a control status of a power increase and a second value representing a control status of a power decrease that are determined based on reception signal quality,

• the method comprising the steps of:
• measuring the quality of a transmission path between the mobile station and each of the base stations, based on a predetermined signal transmitted from each of the base stations with a fixed transmission power;
• and
• determining which transmission power control information is to be used in a transmission power control operation at the mobile station, based on the soft decision value of the transmission power control information transmitted from each of the base stations to the mobile station and the quality of the transmission path between each of the base stations and the mobile station measured in the transmission path quality measuring step,
• the transmission power control information determining step including the steps of:
• generating weight correction control information, giving such a weight to the soft decision value of the transmission power control information transmitted from each of the base stations to the mobile station that a greater weight is given to the transmission power control information transmitted from a base station having a better quality in the transmission path to the mobile station;
• combining the weight correction control information corresponding to the transmission power control information transmitted from the base stations, thereby generating composite transmission power control information, the weight correction control information having been obtained in the weight correction control information generating step;
• and
• performing a hard decision on the value of the composite transmission power control information obtained in the combining step, using a threshold value that is closer to the first value by a predetermined amount from a middle value between the first value and the second value that can be contained in the transmission power control information transmitted from each of the base stations,
• the transmission power control information determining step determining which transmission power control information is to be used in a transmission power control operation at the mobile station, based on the result of the hard decision.

A transmission power control method of controlling transmission power of a mobile station based on a soft decision value of transmission power control information transmitted from a plurality of base stations to the mobile station in a mobile communication system in which each of the base stations to be radio-connected to the mobile station supplies the mobile station with the transmission power control information that can contain a first value representing a control status of a power increase and a second value representing a control status of a power decrease that are determined based on reception signal quality,

• the method comprising the steps of:
• measuring the quality of a transmission path between the mobile station and each of the base stations, based on a predetermined signal transmitted from each of the base stations with a fixed transmission power level;
• and
• determining which transmission power control information is to be used in a transmission power control operation at the mobile station, based on the soft decision value of the transmission power control information transmitted from each of the base stations to the mobile station and the quality of the transmission path between each of the base stations and the mobile station measured in the transmission path quality measuring step,
• the transmission power control information determining step including the steps of:
• generating weight correction control information, giving such a weight to the soft decision value of the transmission power control information transmitted from each of the base stations to the mobile station that a greater weight is given to the transmission power control information transmitted from a base station having a higher quality in the transmission path to the mobile station;
• combining the weight correction control information corresponding to the transmission power control information transmitted from the base stations, the weight correction control information having been obtained in the weight correction control information generating step, thereby generating composite transmission power control information;
• performing a first hard decision on the value of the composite transmission power control information obtained in the combining step, using a first threshold value;
• performing a second hard decision on the value of the composite transmission power control information, using a second threshold value that is different from the first threshold value;
• and
• generating first control information representing one of a control status of a power increase, second control information representing a control status of a power decrease, or third control information representing a control status of power maintenance, based on a decision result of the first hard decision step and a decision result of the second hard decision step,
• the transmission power control information determining step determining that the control information generated from the control information generating step is to be used as the transmission power control information in a transmission power control operation at the mobile station.

A transmission power control method of controlling transmission power of a mobile station based on transmission power control information transmitted from a plurality of base stations to the mobile station in a mobile communication in which each of the base stations to be radio-connected to the mobile station supplies the mobile station with the transmission power control information that is determined based on reception signal quality,

• the method comprising the steps of:
• measuring the quality of a transmission path between the mobile station and each of the base stations, based on a predetermined signal transmitted from each of the base stations with a fixed transmission power;
• measuring a fading condition of the mobile station;
• determining whether the fading condition of the mobile station measured in the fading condition measuring step is better than a predetermined condition;
• and
• performing switch control, validating a first transmission power control information determining step when the fading condition of the mobile station is determined to be better than the predetermined condition in the fading condition determining step, and validating a second transmission power control information determining step when the fading condition of the mobile station is determined not to be better than the predetermined condition in the fading condition determining step,
• the first transmission power control information determining step including the steps of:
• generating weight correction control information, giving such a weight to the transmission power control information transmitted from each of the base stations to the mobile station that a greater weight is given to the transmission power control information transmitted from a base station having a higher quality in the transmission path to the mobile station;
• and
• combining the weight correction control information corresponding to the transmission power control information transmitted from the base station, thereby generating composite transmission power control information, the weight correction control information having been obtained in the weight correction control information generating step,
• the second transmission power control information determining step including the step of selecting the transmission power control information transmitted from the base station having the highest quality in the transmission path to the mobile station measured in the transmission path quality measuring step, the selection being made from the transmission power control information transmitted from the base stations to the mobile station,
• the second transmission power control information determining step determining which transmission power control information is to be used in a transmission power control operation at the mobile station, based on the transmission power control information selected in the selecting step.

A transmission power control method of controlling transmission power of a communication device based on predetermined information supplied from another communication device, the communication device performing radio transmission and reception with the other communication device and transmitting transmission power control information that is to be used in a transmission power control operation in the other communication device and is determined based on reception signal quality,

• the method comprising the steps of:
• determining whether the reception signal quality has become lower than a predetermined quality;
• and
• autonomously controlling the transmission power by increasing the transmission power in accordance with predetermined characteristics, regardless of the predetermined information supplied from the other communication device, when the reception signal quality is determined to have become lower than the predetermined quality in the quality determining step, the transmission power being increased from the transmission power value that is observed at the time of the determination.

A transmission power control device that controls transmission power of a communication device based on predetermined information supplied from another communication device, the communication device performing radio transmission and reception with the other communication device and transmitting transmission power control information that is to be used in a transmission power control operation in the other communication device and is determined based on reception signal quality,

• the transmission power control device comprising:
• a quality determiner that determines whether the reception signal quality has become lower than a predetermined quality;
• and
• an autonomous controller that increases the transmission power in accordance with predetermined characteristics, regardless of the predetermined information supplied from the other communication device, when the quality determiner determines that the reception signal quality has become lower than the predetermined quality, the transmission power being increased from the transmission power value that is observed at the time of the determination.

A mobile station comprising a transmission power control device that controls transmission power when signals are transmitted to and from a base station so as to establish synchronization before information data is sent to the base station that transmits transmission power control information to be used in a transmission power control operation,

• the transmission power control device including a moderate transmission power controller that controls transmission power based on moderate transmission power control information that is designed to control transmission power in accordance with more gradual variation characteristics than the variation characteristics of transmission power controlled based on the transmission power control information transmitted from the base station, after synchronization with a signal from the base station is established at the mobile station.
• 58. The mobile station as claimed in claim 57, wherein the transmission power control device further includes:
• a moderate transmission power control stop determiner that determines whether predetermined conditions for stopping a transmission power control operation by the moderate transmission power controller are satisfied, after the transmission power control operation by the moderate transmission power controller is started;
• and
• a control switcher that switches transmission power control operations from the transmission power control operation by the moderate transmission power controller to a transmission power control operation based on the transmission power control information transmitted from the base station, when the moderate transmission power control stop determiner determines that the predetermined conditions are satisfied.