Communication device and power control method thereof

Abstract

A communication device and a power control method thereof are provided. The power control method, performed by a communication device, includes: determining a power range of a transmit power of an uplink signal; determining a gain switch range based on the power range; when the transmit power of the uplink signal is within the gain switch range, determining a first gain mode for amplifying the uplink signal; and when the transmit power of the uplink signal is out of the gain switch range, determining a second gain mode for amplifying the uplink signal.

What is claimed is: 
     
       1. A power control method, performed by a communication device, comprising:
 determining a power range of a transmit power of an uplink output signal; 
 determining a gain switch range based on the power range transmit power, wherein the gain switch range is defined between a first power and a second power, and wherein the second power is larger than the first power; and  
 when the transmit power of the uplink signal is within the gain switch range, determining a first gain mode for amplifying the uplink signal; and 
 when the transmit power of the uplink signal is out of the gain switch range, determining a second gain mode for amplifying the uplink signal 
 selectively amplifying the output signal using one of a high gain mode and a low gain mode, wherein when the communication device is in the low gain mode and the transmit power increases above the second power, switching from the low gain mode to the high gain mode, and when the communication device is in the high gain mode and the transmit power decreases below the first power, switching from the high gain mode to the low gain mode. 
 
     
     
       2. The power control method of  claim 1 , further comprising:
 receiving a downlink an input signal from an air interface; and 
 determining external information according to the downlink input signal, 
 wherein, the determining the power range step comprises, determining the transmit power of the uplink signal output signal is determined according to the external information. 
 
     
     
       3. The power control method of  claim 1 , further comprising:
 configuring internal information, 
 wherein, the determining the power range step comprises, determining the transmit power of the uplink signal output signal is determined according to the internal information. 
 
     
     
       4. The power control method of  claim 1 , wherein, the when the transmit power of the uplink signal is out of the gain switch range step comprises:
 determining a first signal quality using the first gain mode;   determining a second signal quality using the second mode; and   when the second signal quality is less than or equal to the first signal quality, amplifying the uplink signal with the first gain mode.   
     
     
       5. The power control method of  claim 1 , wherein, the determining the power range step comprises, applying digital modulation and available radio resources are applied to the uplink output signal to determine the transmit power. 
     
     
       6. The power control method of  claim 1 , wherein:
 thea power range of the transmit power comprises an upper power range defined by an upper limit power and an average power; and 
 the step of determining the power range step gain switch range based on the transmit power comprises, determining the gain switch range selecting one of a plurality of predefined gain switch ranges according to the upper power range. 
 
     
     
       7. The power control method of  claim 1 , further comprising:
 receiving a downlink an input signal from an air interface to determine external information; and 
 configuring internal information, 
 wherein the internal information and the external information correspond to first and second priorities, respectively, 
 the determining the power range transmit power step comprises, determining a first power range according to a first transmit power of the uplink output signal according to the external information, and determining a second power range according to a second transmit power of the uplink output signal according to the internal information, and 
 the step of determining the gain switch range step based on the transmit power comprises, determining a first gain switch range according to the first power range transmit power, determining a second gain switch range according to the second power range transmit power, and determining one of the first and the second gain switch ranges as the gain switch range based on the first and second priorities. 
 
     
     
       8. The power control method of  claim 1 , further comprising:
 receiving a downlink an input signal from an air interface to determine external information; and 
 configuring internal information, 
 wherein, the determining the power range transmit power step comprises, determining a first power range according to a first transmit power of the uplink output signal according to the external information, and determining a second power range according to a second transmit power of the uplink output signal according to the internal information, and 
 the step of determining the gain switch range step based on the transmit power comprises, determining a first gain switch range according to the first power range transmit power, determining a second gain switch range according to the second power range transmit power, and determining a corresponding gain switch range of a smaller one of the respective first and the second power ranges of the first and the second transmit powers as the gain switch range. 
 
     
     
       9. The power control method of  claim 1 , further comprising:
 receiving a downlink an input signal from an air interface to determine external information; and 
 configuring internal information, 
 wherein, the determining the power range transmit power step comprises, determining a first power range according to a first transmit power of the uplink output signal according to the external information, and determining a second power range according to a second transmit power of the uplink output signal according to the internal information, 
 the step of determining the gain switch range step based on the transmit power comprises, determining a first gain switch range according to the first power range transmit power, determining a second gain switch range according to the second power range transmit power, and determining a corresponding gain switch range of a larger one of the respective first and the second power ranges of the first and the second transmit powers as the gain switch range. 
 
     
     
       10. A communication device, comprising:
 a controller control circuit, configured to determine a power range of a transmit power of an uplink output signal, and determine a gain switch range based on the power range, when the transmit power of the uplink signal is within the gain switch range, determine a first gain mode, and when the transmit power of the uplink signal is out of the gain switch range, determine a second gain mode transmit power, wherein the gain switch range is defined between a first power and a second power, and wherein the second power is larger than the first power; and 
 a power amplifier, coupled to the controller control circuit, configured to amplify the uplink signal with the first or the second output signal in a low gain mode or a high gain mode, 
 wherein the control circuit is further configured to switch the power amplifier from the low gain mode to the high gain mode when the power amplifier is in the low gain mode and the transmit power increases above the second power, and to switch the power amplifier from the high gain mode to the low gain mode when the power amplifier is in the high gain mode and the transmit power decreases below the first power. 
 
     
     
       11. The communication device of  claim 10 , further comprising:
 a receiver, coupled to the controller control circuit, configured to receive a downlink an input signal from an air interface, 
 wherein the controller control circuit is configured to determine external information according to the downlink input signal, and determine the transmit power of the uplink output signal according to the external information. 
 
     
     
       12. The communication device of  claim 10 , wherein the controller control circuit is adapted to configure internal information, and determine the transmit power of the uplink output signal according to the internal information. 
     
     
       13. The communication device of  claim 10 , wherein the controller is configured to determine a first signal quality using the first gain mode, and determine a second signal quality using the second mode, and when the second signal quality is less than or equal to the first signal quality, the power amplifier is configured to amplify the uplink signal with the first gain mode 
     
     
       14. The communication device of  claim 10 , wherein the controller control circuit is configured to apply digital modulation and available radio resources to the uplink output signal to determine the transmit power. 
     
     
       15. The communication device of  claim 10 , wherein the a power range of the transmit power comprises an upper power range defined by an upper limit power and an average power, and the controller control circuit is configured to determine select one of a plurality of predefined gain switch ranges as the gain switch range according to the upper power range. 
     
     
       16. The communication device of  claim 10 , further comprising:
 a receiver, coupled to the controller control circuit, configured to receive a downlink an input signal from an air interface to determine external information, 
 wherein the controller control circuit is adapted to configure internal information, 
 the internal information and the external information correspond to first and second priorities, respectively, 
 the controller control circuit is configured to determine a first power range according to a first transmit power of the uplink output signal according to the external information, and determine a second power range according to a second transmit power of the uplink output signal according to the internal information, and determine a first gain switch range according to the first power range transmit power, determine a second gain switch range according to the second power range transmit power, and determine one of the first and the second gain switch ranges as the gain switch range based on the first and second priorities. 
 
     
     
       17. The communication device of  claim 10 , further comprising:
 a receiver, coupled to the controller control circuit, configured to receive a downlink an input signal from an air interface to determine external information, 
 wherein the controller control circuit is adapted to configure internal information, 
 the internal information and the external information correspond to first and second priorities, respectively, 
 the controller control circuit is configured to determine a first power range according to a first transmit power of the uplink output signal according to the external information, and determine a second power range according to a second transmit power of the uplink output signal according to the internal information, and determine a first gain switch range according to the first power range transmit power, determine a second gain switch range according to the second power range transmit power, and determine a corresponding gain switch range of a smaller one of the respective first and the second power ranges of the first and the second transmit powers as the gain switch range. 
 
     
     
       18. The communication device of  claim 10 , further comprising:
 a receiver, coupled to the controller control circuit, configured to receive a downlink an input signal from an air interface to determine external information, 
 wherein the controller control circuit is adapted to configure internal information, 
 the internal information and the external information correspond to first and second priorities, respectively; 
 the controller control circuit is configured to determine a first power range according to a first transmit power of the uplink output signal according to the external information, and determine a second power range according to a second transmit power of the uplink output signal according to the internal information, and determine a first gain switch range according to the first power range transmit power, determine a second gain switch range according to the second power range transmit power, and determine a corresponding gain switch range of a larger one of the respective first and the second power ranges of the first and the second transmit powers as the gain switch range. 
 
     
     
       19. The power control method of claim 1, further comprising determining an initial gain mode of the communication device by performing the steps of:
 when the transmit power of the output signal of the communication device on initialization is within the gain switch range, using a default value for the initial gain mode, wherein the default value is one of the high and low gain modes;   when the transmit power of the output signal of the communication device on initialization is lower than the first power, using the low gain mode; and   when the transmit power of the output signal of the communication device on initialization is higher than the second power, using the high gain mode.    
     
     
       20. The communication device of claim 10, wherein the control circuit is further configured to determine an initial gain mode of the communication device, the initial gain mode being determined as follows: when the transmit power of the output signal of the communication device on initialization is within the gain switch range, a default value is used for the initial gain mode, wherein the default value is one of the high and low gain modes; when the transmit power of the output signal of the communication device on initialization is lower than the first power, the low gain mode is used; and when the transmit power of the output signal of the communication device on initialization is higher than the second power, the high gain mode is used.