Base station and transmission power control method
A base station of the present invention performs transmission power control quickly with maintaining communication quality in mobile communications systems, by setting up priority about transmission power control and performing transmission power control sequentially from a channel with a high priority. A channel priority setting unit outputs priority information indicating priority for transmission power control about a plurality of channel information. A power calculation unit outputs total power information of all channels about the plurality of channel information. A power adjustment unit performs power adjustment to the channel information selected on the basis of the priority information when the total power information has larger value than maximum transmission power information.
1. A base station combining a plurality of channel information that is divided as a unit of transmission power control from all the transmission channels and transmitting to mobile stations as downlink data, comprising:
a channel priority setting unit which outputs priority information indicating priority for transmission power control about the plurality of channel information for the transmission channels that include dedicated channels set to a highest priority, control channels set to a next highest priority, and pilot channels set to a lowest priority;
a power calculation unit which outputs a total power information of all channels about the plurality of channel information; and
a power adjustment unit which performs power adjustment to a channel information selected on the basis of the priority information when the total power information has larger value than a maximum transmission power information; and
a controlled variable calculation unit which compares the total power information with the maximum transmission power information, calculates power difference of the total power information and the maximum transmission power information when the total power information has exceeded the maximum transmission power information, and outputs power controlled variable information to perform power control to the channel information with the higher priority before performing power control to the channel information with lower priorities.
2. The base station according to claim 1 , wherein the controlled variable calculation unit sets the power controlled variable information to “0” when a transmission power of the channel information of the highest priority exceeds the power difference, and sets the power controlled variable information according to the power difference when not exceeding the power difference, and wherein the power controlled variable information is set as a fractional multiplier value that is based on the power difference.
3. The base station according to claim 1 , wherein the controlled variable calculation unit sets the power controlled variable information according to power information, when a plurality of channels corresponding to each of the mobile stations exist in the channel information whose power is controlled and have the power information.
4. The base station according to claim 1 , wherein the controlled variable calculation unit sets the power controlled variable information according to spreading ratio information, when a plurality of channels corresponding to each of mobile stations exist in the channel information whose power is controlled and have the spreading ratio information.
5. A transmission power control method of a base station combining a plurality of channel information that is divided as a unit of transmission power control from all the transmission channels and transmitting to mobile stations as a downlink data, comprising:
outputting priority information indicating priority for transmission power control about the plurality of channel information for the transmission channels that include dedicated channels set to a highest priority, control channels set to a next highest priority, and pilot channels set to a lowest priority;
outputting a total power information of all channels about the plurality of channel information; and
performing power adjustment to a channel information selected on the basis of the priority information when the total power information has larger value than a maximum transmission power information; and
comparing the total power information with the maximum transmission power information, calculating power difference of the total power information and the maximum transmission power information when the total power information has exceeded the maximum transmission power information, and outputting power controlled variable information to perform power control to the channel information with the higher priority, in which power control is performed to the channel information with the higher priority before performing power control to the channel information with lower priorities.
6. The transmission power control method according to claim 5 , wherein the power controlled variable information is set to “0” when a transmission power of the channel information of the highest priority exceeds the power difference, and is set according to the power difference when not exceeding the power difference, and wherein the power controlled variable information is set as a fractional multiplier value that is based on the power difference.
7. The transmission power control method according to claim 5 , wherein the power controlled variable information is set according to power information, when a plurality of channels corresponding to each of the mobile stations exist in the channel information whose power is controlled and have the power information.
8. The transmission power control method according to claim 5 , wherein the power controlled variable information is set according to spreading ratio information, when a plurality of channels corresponding to each of mobile stations exist in the channel information whose power is controlled and have the spreading ratio information.