Hughes Electronics Corporation

Brian K Fair

Hassan Zamat

Kumud Patel

Kumud S Patel

In a base transceiver station in a cellular network, a digital signal processor generates a baseband input signal, which is converted to analog and transmitted by a transmitter at radio frequency. In accordance with the present invention, the baseband input signal is scaled by a selected factor from a predetermined table of scaling factors. The scaling factors are determined based on measured output power characteristics of the transmitter and provide frequency compensation caused by filtering ripple and/or attenuation compensation caused by uncertainties in internal attenuators.

Method and apparatus that compensates for output power variations in a

A transmitter in a base transceiver station in a wireless telephony network uses a direct up-conversion scheme to convert an input signal with in-phase and quadrature phase (I, Q) components to a radio frequency within a transmit band. A low-pass filter filters noise from the input signal components and a phase equalizer equalizes the phase distortions caused by the filtering in the input signal components. The signal components are then provided to an up-converter, such as a quadrature modulator, for conversion to a radio frequency signal within a transmit band. The transmitter of the present invention complies with the TIA'S 15-54 emission requirements.r connected to the first low pass filter and a second phase equalizer connected to the second low pass filter.

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Rockville, MD, United States of America

Brian K Fair