Method and apparatus for controlling transmission power of control information in a mobile communication system

A method for controlling power of individual control information transmitted to mobile stations by a base station in a communication system including the base station and at least two mobile stations connected to the base station, the mobile stations receiving a data service from the base station for a preset time period, wherein the base station transmits to the mobile stations control information to be uniquely used by the mobile stations during the data service, a first mobile station receives its own control information transmitted from the base station, and a second mobile station receives its own control information and the control information for the first mobile station transmitted from the base station, the method comprising the steps of:

• determining forward channel conditions of the mobile stations for a previous time period preceding the preset time period;
• calculating power levels required for transmitting control information to the mobile stations for the preset time period, using the forward channel conditions of the mobile stations and transmission power used for transmitting control information to each of the mobile stations for the previous time period;
• and
• transmitting a first control information for the first mobile station at a relatively higher power level out of the calculated required power levels, and transmitting a second control information for the second mobile station at a required power level,
• wherein the second mobile station also receives the first control information for the first mobile station transmitted from the base station.

A base station apparatus for controlling power of individual control information transmitted to mobile stations by a base station in a communication system including the base station and at least two mobile stations connected to the base station, wherein a first mobile station receives first control information transmitted from the base station, and a second mobile station receives second control information transmitted from the base station, the apparatus comprising:

• a receiver for receiving information on forward channel conditions of the first mobile station and the second mobile station for a previous time period preceding the preset time period;
• a channel transmitter for transmitting individual control information to the first mobile station and the second mobile station for the preset time period;
• and
• a transmission power controller for,
• if a channel condition of the first mobile station is worse than a channel condition of the second mobile station, transmitting control information for the first mobile station at a first transmission power, and transmitting control information for the second mobile station at a second transmission power lower than the first transmission power,,
• wherein the second mobile station also receives the first control information for the first mobile station transmitted from the base station.

A base station apparatus for controlling power of individual control information transmitted to mobile stations by a base station in a communication system including the base station and at least two mobile stations connected to the base station, the mobile stations receiving a data service from the base station for a preset time period, wherein the base station transmits to the mobile stations control information to be uniquely used by the mobile stations during the data service, a first mobile station receives its own control information transmitted from the base station, and a second mobile station receives its own control information and the control information for the first mobile station transmitted from the base station, the apparatus comprising:

• a receiver for receiving information on forward channel conditions of the mobile stations for a previous time period preceding the preset time period;
• a channel transmitter for transmitting individual control information to the first mobile station and the second mobile station for the preset time period;
• a required transmission power calculator for calculating power levels required for transmitting the control information to each of the mobile stations for the preset time period using the forward channel condition of each of the mobile stations and transmission power used for transmitting control information to each of the mobile stations for the previous time period;
• and
• a transmission power controller for transmitting control information for the first mobile station at a relatively higher power level out of the calculated required power levels and transmitting control information for the second mobile station at a required power levels,
• wherein the second mobile station also receives the first control information for the first mobile station transmitted from the base station.

A power control apparatus in a communication system including a base station and at least two mobile stations connected to the base station, the mobile stations receiving a data service from the base station for a preset time period, wherein the base station transmits to the mobile stations control information to be uniquely used by the mobile stations during the data service, a first mobile station receives its own control information transmitted from the base station, and a second mobile station receives its own control information and the control information for the first mobile station transmitted from the base station, the apparatus comprising:

• the first mobile station and the second mobile station, each including a transmitter for transmitting individual forward channel condition information of the first mobile station and the second mobile station to the base station;
• the base station including,
• a receiver for receiving the individual forward channel condition information for a previous time period preceding the preset time period;
• a channel transmitter for transmitting individual control information to the first mobile station and the second mobile station for the preset time period;
• and
• a transmission power controller for,
• if a channel condition of the first mobile station is worse than a channel condition of the second mobile station, transmitting control information for the first mobile station at a first transmission power, and transmitting control information for the second mobile station at a second transmission power lower than the first transmission power, and
• if the channel condition of the first mobile station is better than the channel condition of the second mobile station, transmitting control information for both of the first mobile station and the second mobile station at the second transmission power.