Telecommunications – Transmitter – With feedback of modulated output signal
Reexamination Certificate
1998-12-09
2003-02-25
Bost, Dwayne (Department: 2681)
Telecommunications
Transmitter
With feedback of modulated output signal
C455S127500
Reexamination Certificate
active
06526266
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a transmission electric power control device used for a wireless transmitter of a mobile communication apparatus such as a portable telephone. More particularly, the present invention relates to a transmission electric power control device by which an automatic transmission electric power control function can be realized in a transmitter of which a high dynamic range and high linearity are demanded when an electric power convergence offset is controlled by optimizing a control calculating section calculation parameter in the automatic transmission electric power control feedback group in accordance with a transmission electric power designation value.
A common portable telephone (mobile station) is provided with a function for controlling its transmission electric power according to a distance from the base station to the mobile station. Especially, in the case of a portable telephone of CDMA system, in order to minimize an interference with other stations, a transmission electric power control of a high dynamic range and high linearity is demanded. However, the automatic transmission electric power control for meeting the above demand is not conducted in a wireless transmitter under the present condition.
However, in the above application of a wireless transmitter, it is difficult to obtain an absolute accuracy of output electric power of the wireless transmitter. Therefore, when the mobile station approaches to the base station most closely, there is a possibility of interference with other stations. Further, when the mobile station is most distantly separated from the base station, there is a possibility of disconnection. Especially when a transmission electric power control of high linearity is demanded like a portable telephone of CDMA system, it is difficult to turn off an electric power amplifier when the transmission electric power is decreased. Therefore, it is impossible to reduce an electric current in the case of transmission.
SUMMARY OF THE INVENTION
The present has been accomplished to solve the above conventional problems. It is an object of the present invention to provide a controlling apparatus and controlling method for realizing an automatic transmission electric power control by which a transmitting output electric power can be made to approach a target value when a result of calculation is fed back to a gain variable means, which is a component of the transmitter, after a portion of the transmitting output has been taken out, detected, compared with a reference signal and calculated in a transmitter of which a transmission electric power control of a high dynamic range and high linearity is demanded.
In the transmission electric power control device of the present invention, in order to make the transmission electric power accuracy compatible with the transmission electric power variable accuracy in the transmitter of which a high dynamic range and high linearity are demanded, a feedback loop for conducting an automatic transmission electric power control is formed, and a calculation parameter of the control calculating section, which is a component of the loop, is controlled according to a designation value of transmission electric power of the transmitter.
In order to realized that the automatic transmission electric power control is conducted only when an intensity of transmission electric power is relatively high and that the automatic transmission electric power control is not conducted when an intensity of transmission electric power is relatively low, a changeover means for changing over the feedback loop between the valid and invalid is provided, and also a control means for controlling the control calculation parameter is provided, and they are most appropriately controlled according to the transmission electric power designation value of the transmitter. Due to the foregoing, the electric power absolute accuracy can be compensated in a region in which an intensity of transmission electric power is high, and also the linearity accuracy can be compensated between an electric power range in which the automatic transmission electric power control is valid and an electric power range in which the automatic transmission electric power control is invalid.
In order to turn off the electric power source of the electric power amplifier in a transmission electric power range in which the automatic transmission electric power control is valid, there are provided an electric power source control means of the electric power amplifier, a transmitting signal bypass means used in the case of turning off the electric power source of the electric power amplifier, a changeover means for changing over the feedback loop between the valid and invalid, and a control calculation parameter variable means. In the automatic transmission electric power control operation section, according to the transmission electric power designation value, control of turning on and off the electric power amplifier, bypass control of the transmitting signal and control of changing over the operation point of the gain variable means in the transmitter are linked with each other, so that the transmitter electric current can be reduced when the transmission electric power is decreased. Further, the control calculation parameter is made to be variable, so that the absolute accuracy of the transmitting output electric power and the transmitting output variable quantity accuracy can be maintained high in the transition process to the non-operating section.
According to the present invention, when the calculation parameter of the control calculating section in the automatic transmission electric power control feedback loop is optimized according to the transmission electric power designation value, the electric power convergence offset can be controlled, and the automatic transmission electric power control function can be realized in the transmitter of which a high dynamic range and high linearity are demanded, and further the enhancement of the transmission electric power accuracy and the ensuring of the high linearity can be made to be compatible with each other. Even when the electric power amplifier is turned on and off in the automatic transmission electric power control operating section, it is possible to ensure the transmission electric power variable quantity accuracy. Therefore, it is possible to realize a great reduction of electric power consumption of the transmitter.
According to the first aspect of the present invention, it is provided a transmission electric power control device provided in a transmitting device, the transmitting output electric power of which can be controlled, the transmission electric power control device having a feedback loop comprising: a coupler, a detector, an error detection means, a control calculation means, a control calculation parameter generation means, a transmission electric power designation means, a control variable addition means and a gain control means, so that a control calculation parameter in the feedback loop in automatic transmission electric power control can be controlled and optimized in accordance with the individual transmitting output electric power when automatic transmission electric power control is applied in which a portion of the transmitting output is taken out, detected, compared with a reference signal and calculated and the result of the calculation is fed back to a gain control means which is a component of the transmitter. Due to the above arrangement, it is possible to absorb a change in the response characteristic of the system. As a result, it is possible to realize a transmission electric power control of a high dynamic range, high linearity and high accuracy.
According to the second aspect of the present invention, a method of controlling a transmission electric power used for a transmitting device, the transmitting output electric power of which can be controlled, the method of controlling a transmission electric power having a process of feedback loop
Bost Dwayne
Gelin Jean Alland
Pearne & Gordon LLP
LandOfFree
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