Method and arrangement for transmitting and receiving RF signals through various radio interfaces of communication systems
First Claim
Patent Images
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.
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Abstract
A method and arrangement for transmitting and receiving RF signals, associated with different radio interfaces of communication systems, employ a direct conversion based transceiver which substantially comprises one receive signal branch and one transmit signal branch. Mixing frequencies of the different systems are generated by a single common by use of an output frequency divider in combination with the synthesizer, and by use of filtering corresponding to a system channel bandwidth by means of a controllable low-pass filter operating at baseband frequency.
99 Citations
81 Claims
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1. A direct-conversion transmitter comprising:
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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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 38, 39, 40, 41, 42, 43)
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37. A method of using a direct-conversion transmitter comprising:
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generating a digital baseband quadrature signal; converting the digital baseband quadrature signal to an analog baseband transmission signal; generating a mixing signal using a transmit synthesizer common to a plurality of radio interfaces of the direct-conversion transmitter; low-pass filtering the analog baseband transmission signal with a controllable cut-off frequency determined according to which one of the plurality of the radio interfaces of the direct-conversion transmitter is selected; dividing a frequency of the mixing signal at least by two with a frequency divider common to the plurality of radio interfaces of the direct-conversion transmitter, the dividing producing two mixing signal components having a 90-degree phase difference; and amplifying a carrier-frequency signal from a mixer of the direct-conversion transmitter using a controllable gain transmitter amplifier common to the plurality of radio interfaces 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 transmitting a transmission signal generated from the amplified carrier-frequency signal from 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. - View Dependent Claims (44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81)
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Specification