System and method for power control calibration and a wireless communication device

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The presently disclosed subject matter is directed to a technique to control the transmit power and overcome the inherent nonlinearities of control voltage of a variable gain amplifier.
In one exemplary embodiment, a dynamic feedback loop is provided that permits precise control of transmit power without the need for a linearizer.
Although the importance of power control in a CDMA system has been discussed and the examples presented herein are implementations within a CDMA device, virtually all wireless devices utilize variable gain amplifiers and suffer from the effects of nonlinearity in the gain control.
The presently disclosed subject matter provides a solution to the problem of nonlinear gain control and is broadly applicable to any wireless device.
The presently disclosed subject matter is not limited to CDMA technology.
FIG.
4 is a functional block diagram of one exemplary embodiment of the presently disclosed subject matter to control transmit power.
In the example illustrated in FIG.
4, the presently disclosed subject matter is embodied in a system 100 that dynamically adjusts the transmit power using a feedback loop.
The system 100 includes a receiver portion 104 and a transmitter portion 106.
The antenna 12 is coupled to the transmitter portion 104 and the receiver portion 106 through a diplexer 108.
The diplexer 108 permits the receiver portion 104 and the transmitter portion 106 to share a common antenna (i.
e.
, the antenna 12).
The diplexer 108 is a common device and need not be described in greater detail herein.
The receiver portion 104 includes certain elements that have previously been discussed in the functional block diagram of FIG.
1.
However, for the sake of clarity, the receiver portion 104 in FIG.
4 only includes certain elements from FIG.
1.
Specifically, the RSSI is provided to the linearizer 40.
The output of the linearizer 40 is coupled to the DAC 42 which, in turn, generates the control voltage VCONT.
The control voltage VCONT controls the gain of the VGA 18