Patent ID: 8755834
Filing Date: 2014-06-17
Classification: H04B,H04W

Abstract:
1. A direct-conversion transmitter comprising: a digital signal processor; a digital-to-analog converter configured to convert a digital baseband quadrature signal to an analog baseband transmission signal; a transmit synthesizer common to a plurality of radio interfaces of the direct-conversion transmitter and configured to generate a mixing signal; a controllable low-pass filter common to a plurality of radio interfaces of the direct-conversion transmitter, the controllable low-pass filter configured to perform filtering of the analog baseband transmission signal with a controllable cut-off frequency determined according to which one of the plurality of radio interfaces of the direct-conversion transmitter is selected; a frequency divider common to the plurality of radio interfaces of the direct-conversion transmitter and configured to divide a frequency of the mixing signal at least by two, wherein the dividing produces two mixing signal components having a 90-degree phase difference; a controllable gain transmitter amplifier common to the plurality of radio interfaces of the direct-conversion transmitter and configured to amplify a carrier-frequency signal from a mixer of the direct-conversion transmitter at a gain controlled according to which one of the plurality of radio interfaces of the direct-conversion transmitter is selected; and an antenna, wherein at least one of the plurality of radio interfaces of the direct-conversion transmitter comprises a modulation, a channel spacing, and a channel bit rate that at least one other of the plurality of radio interfaces does not have.