Method and Arrangement for Transmitting and Receiving RF Signals Through Various Radio Interfaces of Communication Systems

• US 20140242929A1
• Filed: 05/07/2014
• Published: 08/28/2014
• Est. Priority Date: 11/26/1998
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Visnen, Risto, Kaltiokallio, Kim
• Granted Patent: US 8,838,049 B1
• Time in Patent Office: Days
• US Class Current: 455/125
• CPC Class Codes: H04B 1/0057 using diplexing or multiplexing filters for selecting the desired band
• CPC Class Codes: H04B 1/0078 with a common intermediate frequency amplifier for the different intermediate frequencies, e.g. when using switched intermediate frequency filters
• CPC Class Codes: H04B 1/0082 with a common local oscillator for more than one band
• CPC Class Codes: H04B 1/30 for homodyne or synchrodyne receivers demodulator circuits H03D1/22
• CPC Class Codes: H04B 1/406 with more than one transmission mode, e.g. analog and digital modes
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

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.

Claims

1. (canceled)

2. A direct-conversion transmitter comprising:

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 the plurality of radio interfaces of the direct-conversion transmitter, the controllable low-pass filter configured to perform filtering of an analog baseband transmission signal using a controllable cut-off frequency 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; and

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, 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.

3. The direct-conversion transmitter of claim 2, wherein the controllable gain transmitter amplifier is configured to perform automatic gain control.

4. The direct-conversion transmitter of claim 2, wherein at least two of the plurality of the radio interfaces of the direct conversion transmitter have different transmission frequencies.

5. The direct-conversion transmitter of claim 2, wherein at least two of the plurality of the radio interfaces of the direct conversion transmitter have different transmission frequency ranges.

6. The direct-conversion transmitter of claim 2, wherein at least two of the plurality of the radio interfaces of the direct conversion transmitter have overlapping transmission frequency ranges.

7. The direct-conversion transmitter of claim 2, wherein at least two of the plurality of the radio interfaces of the direct conversion transmitter have the same transmission frequency range.

8. The direct-conversion transmitter of claim 2, wherein at least two of the plurality of the radio interfaces of the direct conversion transmitter have adjacent transmission frequency ranges.

9. The direct-conversion transmitter of claim 2, wherein a first radio interface of the plurality of radio interfaces of the direct conversion transmitter operates at a first transmission frequency, wherein a second radio interface of the plurality of the radio interfaces of the direct conversion transmitter operates at a second transmission frequency, and wherein the first transmission frequency and the second transmission frequency are within 100 MHz of each other.

10. The direct-conversion transmitter of claim 2, wherein a first radio interface of the plurality of radio interfaces employs a time division multiple access method and a second radio interface of the plurality of radio interfaces employs a code division multiple access method.

11. The direct-conversion transmitter of claim 2, further comprising a control block circuit configured to generate at least one control signal that indicates which of the plurality of radio interfaces is selected, wherein the control block circuit comprises a microprocessor.

12. The direct-conversion transmitter of claim 2, further comprising a power amplifier configured to amplify the carrier-frequency signal amplified by the controllable gain transmitter amplifier and having a controllable operating frequency band set according to which one of the plurality of radio interfaces is selected.

13. The direct-conversion transmitter of claim 2, wherein a first radio interface of the plurality of radio interfaces employs a WCDMA system and a second radio interface of the plurality of radio interfaces employs a Global System for Mobile communications (GSM) system.

14. The direct-conversion transmitter of claim 2, wherein the direct-conversion transmitter is part of a transceiver that comprises a direct-conversion receiver.

15. The direct-conversion transmitter of claim 2, wherein the plurality of radio interfaces further differ from each other by multiple access method.

16. The direct-conversion transmitter of claim 2, wherein the plurality of radio interfaces further differ from each other by duplex method.

17. The direct-conversion transmitter of claim 2, wherein the plurality of radio interfaces further differ from each other by RF bandwidth.

18. The direct-conversion transmitter of claim 2, wherein the carrier-frequency signal comprises a signal from the mixing signal components mixed with the analog baseband transmission signal filtered by the controllable low-pass filter.

19. The direct-conversion transmitter of claim 2, wherein the controllable low-pass filter is configured to filter the analog baseband transmission signal through a signal path that is common for each of the plurality of radio interfaces.

20. The direct-conversion transmitter of claim 2, wherein the controllable low-pass filter and the controllable gain transmitter amplifier are part of a transmit path common to the plurality of radio interfaces.

21. The direct-conversion transmitter of claim 2, wherein the controllable low pass filter, the mixer, and the controllable gain transmitter amplifier are part of a transmit path common to the plurality of radio interfaces.

22. The direct-conversion transmitter of claim 2, wherein the mixer is common to the plurality of radio interfaces.

30. The direct-conversion transmitter of claim 2, further comprising a power amplifier, wherein the controllable low-pass filter, the mixer, the power amplifier, and the controllable gain transmitter amplifier are part of a transmit path common to the plurality of radio interfaces.

31. The direct-conversion transmitter of claim 2, further comprising a bandpass filter, wherein the controllable low-pass filter, the controllable gain transmitter amplifier, and the bandpass filter are part of a transmit path common for the plurality of radio interfaces.

23. A direct-conversion transmitter comprising:

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 the plurality of radio interfaces of the direct-conversion transmitter, the controllable low-pass filter configured to perform filtering of an analog baseband transmission signal to produce a filtered analog baseband transmission signal, wherein the controllable low-pass filter is configured to use a controllable cut-off frequency 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; and

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 generated from the filtered analog baseband transmission signal mixed with the two mixing signal components, at a gain controlled according to which one of the plurality of radio interfaces of the direct-conversion transmitter is selected, wherein at least one of the plurality of radio interfaces of the direct-conversion transmitter comprises at least one modulation, at least one channel spacing, and at least one channel bit rate that at least one other of the plurality of radio interfaces does not have.

24. The direct-conversion transmitter of claim 23, further comprising a mixer configured to generate the carrier-frequency signal.

25. The direct-conversion transmitter of claim 23, further comprising:

a digital signal processor configured to generate a digital baseband quadrature signal;

a digital-to-analog converter configured to convert the digital baseband quadrature signal to the analog baseband transmission signal; and

an antenna.

26. A direct-conversion transmitter comprising:

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 the plurality of radio interfaces of the direct-conversion transmitter, the controllable low-pass filter configured to perform filtering of an analog baseband transmission signal to produce a filtered analog baseband transmission signal, wherein the controllable low-pass filter is configured to use a controllable cut-off frequency 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; and

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 comprising a signal that is from the filtered analog baseband transmission signal mixed with the two mixing signal components, at a gain controlled according to which one of the plurality of radio interfaces of the direct-conversion transmitter is selected, 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.

27. The direct-conversion transmitter of claim 26, further comprising:

a digital signal processor configured to generate a digital baseband quadrature signal;

a digital-to-analog converter configured to convert the digital baseband quadrature signal to the analog baseband transmission signal; and

an antenna.

28. A direct-conversion transmitter comprising:

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 the plurality of radio interfaces of the direct-conversion transmitter, the controllable low-pass filter configured to perform filtering of an analog baseband transmission signal to produce a filtered analog baseband transmission signal, wherein the controllable low-pass filter is configured to use a controllable cut-off frequency 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; and

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 at a gain controlled according to which one of the plurality of radio interfaces of the direct-conversion transmitter is selected, wherein the carrier-frequency signal is based on the filtered analog baseband transmission signal mixed with the two mixing signal components, and wherein at least one of the plurality of radio interfaces employs a GSM system and at least one other of the plurality of radio interfaces employs a WCDMA system.

29. The direct-conversion transmitter of claim 28, further comprising:

a digital signal processor configured to generate a digital baseband quadrature signal;

a digital-to-analog converter configured to convert the digital baseband quadrature signal to the analog baseband transmission signal; and

an antenna.