Method and arrangement for transmitting and receiving RF signals through various radio interfaces of communication systems

• US 8,768,408 B2
• Filed: 06/10/2008
• Issued: 07/01/2014
• Est. Priority Date: 11/26/1998
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Vaisanen, Risto, Kaltiokallio, Kim
• Primary Examiner(s): Le, Lana N
• Application Number:
  US12/136,465
• Publication Number:
  US 20090135781A1
• Time in Patent Office: 2,212 Days
• Field of Search: 4555521-5531, 4551271-1275, 455/114.2, 455/67.13, 455 76- 78
• US Class Current: 455/552.1
• 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. A direct-conversion transceiver capable of operating with different radio interfaces including a first radio interface conforming to a code division multiple access (CDMA) system and a second radio interface conforming to a time division multiple access (TDMA) system, comprising:

a first controllable bandpass filter configured to filter a received signal using one of a first plurality of passbands selected according to at least one control signal corresponding to a selected one of the different radio interfaces, wherein the first controllable bandpass filter has a signal path common to both the first radio interface and the second radio interface;

a low-noise amplifier configured to amplify the filtered received signal according to the at least one control signal corresponding to the selected one of the different radio interfaces, which controls an amount of gain, wherein the low-noise amplifier has a signal path common to both the first radio interface and the second radio interface;

a first programmable synthesizer configured to generate a first mixing signal according to the at least one control signal corresponding to the selected one of the different radio interfaces, wherein the first programmable synthesizer has a signal path common to both the first radio interface and the second radio interface;

a first frequency divider coupled to the first programmable synthesizer and configured to divide a first frequency of the first mixing signal by two to provide a first divided frequency signal according to the at least one control signal corresponding to the selected one of the different radio interfaces;

a first mixer coupled to the low-noise amplifier and configured to mix the amplified and filtered received signal with the first divided frequency signal to produce a first baseband quadrature signal, wherein the first mixer has a signal path common to both the first radio interface and the second radio interface and wherein the first mixer produces the first baseband quadrature signal on the basis of two 90-degree phase-shifted first components produced from the first frequency divider and is operable to process either a TDMA signal or a CDMA signal;

a first low-pass filter coupled to the first mixer and configured to low-pass filter the first baseband quadrature signal according to the at least one control signal corresponding to the selected one of the different radio interfaces, wherein the first low-pass filter has a signal path common to both the first radio interface and the second radio interface and is operable to process either the TDMA signal or the CDMA signal;

a first gain-controlled amplifier coupled to the first low-pass filter and configured to provide gain-controlled amplification of the low-pass filtered first baseband quadrature signal, wherein the first gain-controlled amplifier has a signal path common to both the first radio interface and the second radio interface and is operable to process either the TDMA signal or the CDMA signal;

an analog-to-digital converter coupled to the first gain-controlled amplifier and configured to convert to digital form an output of the first gain-controlled amplifier;

a digital signal processor configured to receive digital output from the analog-to-digital converter and to further process said digital output;

a digital-to-analog converter coupled to the digital signal processor and configured to receive a second baseband quadrature signal from the digital signal processor and to provide analog output signals;

a second low-pass filter coupled to the digital-to-analog converter and configured to low-pass filter the analog output signals from the digital-to-analog converter according to the at least one control signal corresponding to the selected one of the different radio interfaces, wherein the second low-pass filter has a signal path common to both the first radio interface and the second radio interface and is operable to process either the TDMA signal or the CDMA signal;

a second programmable synthesizer configured to generate a second mixing signal according to the at least one control signal corresponding to the selected one of the different radio interfaces, wherein the second programmable synthesizer has a signal path common to both the first radio interface and the second radio interface;

a second frequency divider coupled to the second programmable synthesizer and configured to divide a second frequency of the second mixing signal by two to provide a second divided frequency signal according to the at least one control signal corresponding to the selected one of the different radio interfaces;

a second mixer coupled to the second low-pass filter and configured to mix signals from the second low-pass filter and the second frequency divider to produce a carrier-frequency transmission signal, wherein the second mixer has a signal path common to both the first radio interface and the second radio interface and wherein the second mixer produces the carrier-frequency transmission signal on the basis of two 90-degree phase-shifted second components produced from the second frequency divider and is operable to process either the TDMA signal or the CDMA signal;

a second gain-controlled amplifier coupled to the second mixer and configured to control gain according to the at least one control signal corresponding to the selected one of the different radio interfaces, wherein the second gain-controlled amplifier has a signal path common to both the first radio interface and the second radio interface and is operable to process either the TDMA signal or the CDMA signal;

a power amplifier coupled to the second gain-controlled amplifier and configured to produce an amplified output using a frequency band determined on the basis of the at least one control signal corresponding to the selected one of the different radio interfaces, wherein the power amplifier has a signal path common to both the first radio interface and the second radio interface;

a second controllable bandpass filter configured to filter the amplified output of the power amplifier with one of a second plurality of passbands selected according to the at least one control signal corresponding to the selected one of the different radio interfaces, and wherein the second controllable bandpass filter has a signal path common to both the first radio interface and the second radio interface; and

a microprocessor configured to generate the at least one control signal to cause selection of the selected one of the different radio interfaces.

2. The direct-conversion transceiver of claim 1, wherein the code division multiple access (CDMA) system is a WCDMA system and the time division multiple access (TDMA) system is a Global System for Mobile communications (GSM) system.

3. An apparatus comprising:

a direct-conversion transmitter configured to transmit radio-frequency signals of mobile communication systems using a plurality of radio interfaces;

wherein the direct-conversion transmitter comprises;

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

a transmit synthesizer common to the plurality of radio interfaces and configured to generate a mixing signal;

a controllable low-pass filter configured to perform channel filtering of the analog baseband transmission signal using a controllable cut-off frequency to produce a low-pass filtered signal, wherein the controllable cut-off frequency corresponds to which one of the plurality of radio interfaces is selected, and wherein the controllable low-pass filter is configured to filter the analog baseband transmission signal through a common signal path that is used for each of the plurality of radio interfaces;

a frequency divider common to the plurality of radio interfaces 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 mixer common to the plurality of radio interfaces and configured to produce a carrier-frequency signal based on the low-passed filtered signal and the two mixing signal components; and

a controllable gain transmitter amplifier common to the plurality of radio interfaces and configured to amplify the carrier-frequency signal at a gain controlled according to which one of the plurality of radio interfaces is selected,

wherein at least one of the plurality of radio interfaces includes at least one modulation type and at least one channel bit rate that at least one other of the plurality of radio interfaces does not have.

4. The apparatus of claim 3, wherein the controllable gain transmitter amplifier is configured to perform automatic gain control.

5. The apparatus of claim 3, further comprising:

a bandpass filter configured to filter the carrier-frequency signal amplified by the controllable gain transmitter amplifier, and including a selectable pass band set according to which one of the plurality of radio interfaces is selected.

6. The apparatus of claim 3, wherein at least two of the plurality of radio interfaces have different transmission frequencies.

7. The apparatus of claim 3, 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.

8. The apparatus of claim 3, further comprising a power amplifier configured to further 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.

9. The apparatus of claim 3, further comprising a direct conversion receiver comprising:

a bandpass filter configured to filter a received second carrier-frequency signal,

a first receiver amplifier configured to amplify the received second carrier-frequency signal filtered by the bandpass filter,

a receiver synthesizer configured to generate a receiver mixing signal at a receive frequency,

a receiver mixer configured to generate a complex baseband signal by mixing the receiver mixing signal with the received second carrier-frequency signal amplified by the first receiver amplifier,

a receiver low-pass filter configured to filter the complex baseband signal,

a second receiver amplifier configured to amplify the complex baseband signal filtered by the receiver low-pass filter, and

an analog-to-digital converter configured generate a receiver digital baseband signal by converting the complex baseband signal amplified by the second receiver amplifier to digital form.

10. The apparatus of claim 3, 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.

11. The apparatus of claim 3, wherein at least one of the plurality of radio interfaces includes at least one multiple access method that at least one other of the plurality of radio interfaces does not have.

12. The apparatus of claim 11, wherein the plurality of radio interfaces further differ from each other by at least channel spacing.

13. The apparatus of claim 12, wherein the plurality of radio interfaces further differ from each other by at least duplex method.

14. The apparatus of claim 13, wherein the plurality of radio interfaces further differ from each other by at least RF bandwidth.

15. The apparatus of claim 11, wherein the plurality of radio interfaces further differ from each other by at least duplex method.

16. The apparatus of claim 11, wherein the plurality of radio interfaces further differ from each other by at least RF bandwidth.

17. The apparatus of claim 3, wherein the plurality of radio interfaces further differ from each other by at least multiple access method.

18. The apparatus of claim 17, wherein the plurality of radio interfaces further differ from each other by at least channel spacing.

19. The apparatus of claim 18, wherein the plurality of radio interfaces further differ from each other by at least duplex method.

20. The apparatus of claim 19, wherein the plurality of radio interfaces further differ from each other by at least RF bandwidth.

21. The apparatus of claim 17, wherein the plurality of radio interfaces further differ from each other by at least duplex method.

22. The apparatus of claim 17, wherein the plurality of radio interfaces further differ from each other by at least RF bandwidth.

23. The apparatus of claim 3, wherein the plurality of radio interfaces further differ from each other by at least channel spacing.

24. The apparatus of claim 23, wherein the plurality of radio interfaces further differ from each other by at least duplex method.

25. The apparatus of claim 23, wherein the plurality of radio interfaces further differ from each other by at least RF bandwidth.

26. The apparatus of claim 3, wherein the plurality of radio interfaces further differ from each other by at least duplex method.

27. The apparatus of claim 26, wherein the plurality of radio interfaces further differ from each other by at least RF bandwidth.

28. The apparatus of claim 3, wherein the plurality of radio interfaces further differ from each other by at least RF bandwidth.

29. The apparatus of claim 3, wherein at least two of the plurality of radio interfaces have a common transmission frequency.

30. The apparatus of claim 3, wherein at least two of the plurality of radio interfaces have a common transmission frequency range.

31. The apparatus of claim 3, wherein at least two of the plurality of radio interfaces have at least partially overlapping transmission frequency ranges.

32. The apparatus of claim 3, wherein at least two of the plurality of radio interfaces have transmission frequency ranges that are adjacent to each other.

33. The apparatus of claim 3, wherein at least two of the plurality of radio interfaces have transmission frequency ranges separated by about 41 MHz.

34. The apparatus of claim 3, wherein at least two of the plurality of radio interfaces have transmission frequency ranges separated by about 2 MHz, 20 MHz, 91 MHz, 135 MHz, 419 MHz, 628 MHz, 861 MHz, 964 MHz, 1005 MHz, 1031 MHz, 1046 MHz, 1051 MHz, or 1071 MHz.

35. The apparatus of claim 3, wherein a separation of respective transmission frequency bands of at least two of the plurality of radio interfaces ranges from about 2 MHz to about 1071 MHz.

36. The apparatus of claim 3, further comprising a direct-conversion receiver configured to receive a second carrier-frequency signal and produce, based on which one of the plurality of radio interfaces is selected, an analog baseband reception signal by direct conversion of the second carrier-frequency signal.

37. The apparatus of claim 3, wherein a first radio interface of the plurality of radio interfaces employs a TDMA multiple access method and a second radio interface of the plurality of radio interfaces employs a CDMA multiple access method.

38. A method comprising:

transmitting radio-frequency signals through direct conversion and using a plurality of radio interfaces of mobile communication systems;

wherein the transmitting through direct conversion includes;

converting a digital baseband quadrature signal to an analog baseband transmission signal;

low-pass filtering the analog baseband transmission signal using a controllable cut-off frequency to produce a low-pass filtered signal, wherein the controllable cut-off frequency is corresponds to which one of the plurality of radio interfaces is selected, wherein the low-pass filtering of the analog baseband transmission signal occurs through a common signal path that is used for each of the plurality of radio interfaces;

generating a mixing signal at a transmission frequency using a transmit synthesizer common to the plurality of radio interfaces;

dividing a frequency of the mixing signal at least by two with a frequency divider common to the plurality of radio interfaces, the dividing producing two mixing signal components having a 90-degree phase difference;

generating, with a mixer common to the plurality of radio interfaces, a carrier-frequency signal based on the low-pass filtered signal and the two mixing signal components; and

amplifying the carrier-frequency signal using a controllable gain transmitter amplifier common to the plurality of radio interfaces at a gain controlled according to which one of the plurality of radio interfaces is selected,

wherein at least one of the plurality of radio interfaces includes at least one modulation type and at least one channel bit rate that at least one other of the plurality of radio interfaces does not have.

39. The method of claim 38, wherein each of the plurality of radio interfaces operates at a different transmission frequency.

40. The method of claim 38, further comprising:

performing automatic gain control with the controllable gain transmitter amplifier.

41. The method of claim 38, further comprising:

bandpass filtering the carrier-frequency signal amplified by the controllable gain transmitter amplifier using a selectable pass band set according to which one of the plurality of radio interfaces is selected.

42. The method of claim 38, further comprising:

amplifying the carrier-frequency signal amplified by the controllable gain transmitter amplifier with a power amplifier having a controllable operating frequency band determined according to which one of the plurality of radio interfaces is selected.

43. The method of claim 38, 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.

44. The method of claim 38, further comprising generating at least one control signal that indicates which of the plurality of radio interfaces is selected.

45. The method of claim 38, wherein at least one of the plurality of radio interfaces includes at least one multiple access method that at least one other of the plurality of radio interfaces does not have.

46. The method of claim 45, wherein the plurality of radio interfaces further differ from each other by at least channel spacing.

47. The method of claim 46, wherein the plurality of radio interfaces further differ from each other by at least duplex method.

48. The method of claim 47, wherein the plurality of radio interfaces further differ from each other by at least RF bandwidth.

49. The method of claim 45, wherein the plurality of radio interfaces further differ from each other by at least duplex method.

50. The method of claim 45, wherein the plurality of radio interfaces further differ from each other by at least RF bandwidth.

51. The method of claim 38, wherein the plurality of radio interfaces further differ from each other by at least multiple access method.

52. The method of claim 51, wherein the plurality of radio interfaces further differ from each other by at least channel spacing.

53. The method of claim 52, wherein the plurality of radio interfaces further differ from each other by at least duplex method.

54. The method of claim 53, wherein the plurality of radio interfaces further differ from each other by at least RF bandwidth.

55. The method of claim 51, wherein the plurality of radio interfaces further differ from each other by at least duplex method.

56. The method of claim 51, wherein the plurality of radio interfaces further differ from each other by at least RF bandwidth.

57. The method of claim 38, wherein the plurality of radio interfaces further differ from each other by at least channel spacing.

58. The method of claim 57, wherein the plurality of radio interfaces further differ from each other by at least duplex method.

59. The method of claim 57, wherein the plurality of radio interfaces further differ from each other by at least RF bandwidth.

60. The method of claim 38, wherein the plurality of radio interfaces further differ from each other by at least duplex method.

61. The method of claim 60, wherein the plurality of radio interfaces further differ from each other by at least RF bandwidth.

62. The method of claim 38, wherein the plurality of radio interfaces further differ from each other by at least RF bandwidth.

63. The method of claim 38, wherein at least two of the plurality of radio interfaces have a common transmission frequency.

64. The method of claim 38, wherein at least two of the plurality of radio interfaces have a common transmission frequency range.

65. The method of claim 38, wherein at least two of the plurality of radio interfaces have at least partially overlapping transmission frequency ranges.

66. The method of claim 38, wherein at least two of the plurality of radio interfaces have transmission frequencies that are adjacent to each other.

67. The method of claim 38, wherein at least two of the plurality of radio interfaces have transmission frequency ranges separated by about 41 MHz.

68. The method of claim 38, wherein at least two of the plurality of radio interfaces have transmission frequency ranges separated by about 2 MHz, 20 MHz, 91 MHz, 135 MHz, 419 MHz, 628 MHz, 861 MHz, 964 MHz, 1005 MHz, 1031 MHz, 1046 MHz, 1051 MHz, or 1071 MHz.

69. The method of claim 38, wherein a separation of respective transmission frequency bands of at least two of the plurality of radio interfaces ranges from about 2 MHz to about 1071 MHz.

70. The method of claim 38, further comprising receiving a second carrier-frequency signal and producing, based on which one of the plurality of radio interfaces is selected, an analog baseband reception signal by direct conversion of the second carrier-frequency signal.

71. The method of claim 38, wherein a first radio interface of the plurality of radio interfaces employs a TDMA multiple access method and a second radio interface of the plurality of radio interfaces employs a CDMA multiple access method.