Base and Repeater Stations

• US 20110142104A1
• Filed: 07/16/2008
• Published: 06/16/2011
• Est. Priority Date: 07/16/2008
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Johansson, Martin Nils, Coldrey, Mikael, Petersson, Sven Oscar
• Granted Patent: US 8,594,158 B2
• Time in Patent Office: Days
• US Class Current: 375/211
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04B 7/1555 Selecting relay station antenna mode, e.g. selecting omnidirectional -, directional beams, selecting polarizations

Abstract

A base station repeater station pair, comprising: a base station (1) having an input for a broadcast signal (s(t)) and being arranged to transmit, in use, a transfer signal over a link (3) using electromagnetic (EM) radiation; and a repeater station (2) arranged to receive, in use and through EM radiation, the transfer signal from the base station (1) and from the transfer signal broadcast the broadcast signal using EM radiation, in which the link (3) between the base station (1) and the repeater station (2) over which the transfer signal is passed in use comprises a dual polarised link, whereby the base station (1) is arranged to transmit the transfer signal over the link (3) with two different polarisations, and the repeater station (2) is arranged to receive the transfer signal from the link as two differently polarised versions. Also disclosed area base station and a method of using the above.

Claims

1. A base station—

repeater station pair, comprising;

a base station having an input for a broadcast signal and being arranged to transmit, in use, a transfer signal over a link using electromagnetic (EM) radiation; and

a repeater station arranged to receive, in use and through EM radiation, the transfer signal from the base station and from the transfer signal broadcast the broadcast signal using EM radiation,

in which the link between the base station and the repeater station over which the transfer signal is passed in use comprises a dual polarised link, whereby the base station is arranged to transmit the transfer signal over the link with two different polarisations, and the repeater station is arranged to receive the transfer signal from the link as two differently polarised versions.

2. The pair of claim 1, in which the base station is also arranged so as to broadcast using EM radiation the broadcast signal, in use.

3. The pair of claim 1 or claim 2, in which the repeater station comprises two broadcast antennas on which the broadcast signal is transmitted in use, the repeater station being arranged such that the relative amplitude and phase of the broadcast signal as transmitted from the broadcast antennas depends upon the relative amplitude and phase of the two received transfer signal versions.

4. The pair of claim 3, in which the repeater station is arranged such that, as between the two received versions of the transfer signal on the one hand and the broadcast signal as transmitted on the two broadcast antennas on the other, one or both of the ratio of the amplitudes of the two signals and the phase difference between them is preserved.

5. The pair of any of claim 3 or 4, in which the repeater station is arranged only to amplify each version of the transfer signal before transmitting such on a respective broadcast antenna.

6. The pair of claim 3 or 4, in which the repeater station comprises a hybrid network, such as a Butler matrix, the transfer antennas in the repeater station being connected to the broadcast antennas in the repeater station by means of the hybrid network.

7. The pair of claim 6, in which the hybrid network is arranged so as to, in use, take the signals received at the repeater station transfer antennas and to process them and output the processed signals to the repeater station broadcast antennas, such that the phase difference in the processed signals depends on the relative amplitudes of versions of the transfer signal and the relative amplitudes of the processed signals depends upon the phase difference between the versions of the transfer signal.

8. The pair of claim 7, in which an amplifier is also provided for each transfer antenna in the repeater station, in which the amplifier is connected between the relevant transfer antenna and the hybrid network.

9. The pair of any preceding claim, in which the base station comprises two differently polarised transfer antennas, which form part of the link and from which the transfer signal is transmitted in use.

10. The pair of claim 9, in which the repeater station comprises two differently polarised transfer antennas, which form part of the link and on each of which the repeater station is arranged to receive one of the versions of the transfer signal.

11. The pair of claim 10, in which the transfer antennas of either or both the base and repeater stations are orthogonally polarised with respect to each other.

12. The pair of claim 10 or claim 11, in which each transfer antenna in the repeater is connected to a respective broadcast antenna in the repeater.

13. The pair of claim 12 apart from as dependent from claim 6, in which the connection is through an amplifier, without any other signal processing equipment between the transfer antennas and the broadcast antennas in the repeater station.

14. The pair of any of claims 10 to 13, in which the repeater station broadcast antennas are not differently polarised.

15. The pair of any of claims 10 to 13, in which the repeater station broadcast antennas are differently polarised.

16. The pair of any of claims 10 to 15, in which the broadcast antennas on the repeater station are spaced apart, so as to form an antenna array.

17. The pair of claim 16, in which the antenna array of the repeater station is arranged such that, in use, a combined beam is formed, and in which the base station is arranged to control the relative phases and amplitudes of the signals transmitted from the broadcast antennas on the repeater station, the pair being arranged such that the combined beam can be steered and/or shaped by varying the relative phase and/or amplitude of the signals transmitted over the link.

18. The pair of any preceding claim, in which the base station comprises two phase and/or amplitude modulators and is arranged so as to apply the broadcast signal to the two phase and/or amplitude modulators, the phase and/or amplitude modulators being arranged so as to, in use, apply different shifts in amplitude and/or phase to the broadcast signal, and to output the respective resultant signals to respective ones of the transfer antennas.

19. The pair of claim 18, in which the broadcast signal comprises two sub-signals, in which the phase and/or amplitude modulators are arranged to apply different shifts to the two sub-signals.

20. The pair of claim 19, in which the shifts are such that each of the sub-signals is transmitted from a different broadcast antenna at the repeater station.

39. The pair of any of claims 1 to 20, comprising a repeater station according to any of claims 21 to 34 together with the base station of any of claims 35 to 38.

21. A repeater station having two transfer antennas on which the repeater station is arranged to receive a transfer signal comprising electromagnetic (EM) radiation, two broadcast antennas on which the repeater station is arranged to transmit a broadcast signal comprising EM radiation dependent upon the transfer signal, in which the two transfer antennas are differently polarised.

22. The repeater station of claim 21, arranged such that the relative amplitude and phase of the broadcast signal as transmitted from the broadcast antennas depends upon the relative amplitude and phase of the transfer signal as received at the two transfer antennas.

23. The repeater station of claim 22, in which the repeater station is arranged such that in use, as between the transfer signal as received at the two transfer antennas on the one hand and the broadcast signal as transmitted on the two broadcast antennas on the other, one or both of the ratio of the amplitudes of the two signals and the phase difference between them is preserved.

24. The repeater station of claim 23, arranged only as to amplify each version of the transfer signal before transmitting such on a respective broadcast antenna.

25. The repeater station of claim 22 or 23, in which the repeater station comprises a hybrid network, such as a Butler matrix, the transfer antennas in the repeater station being connected to the broadcast antennas in the repeater station by means of the hybrid network.

26. The repeater station of claim 25, in which the hybrid network is arranged so as to, in use, take the signals received at the repeater station transfer antennas and to process them and output the processed signals to the repeater station broadcast antennas, such that the phase difference in the processed signals depends on the relative amplitudes of versions of the transfer signal and the relative amplitudes of the processed signals depends upon the phase difference between the versions of the transfer signal.

27. The repeater station of claim 26, in which an amplifier is also provided for each transfer antenna in the repeater station, in which the amplifier is connected between the relevant transfer antenna and the hybrid network.

28. The repeater station of any of claims 21 to 27, in which the transfer antennas are orthogonally polarised with respect to each other.

29. The repeater station of any of claims 21 to 28, in which each transfer antenna is connected to a respective broadcast antenna through an amplifier.

30. The repeater station of claim 29 apart from as dependent from claim 25, in which the connection between each transfer antenna and the respective broadcast antenna is devoid of any other signal processing equipment.

31. The repeater station of any of claims 21 to 30, in which the broadcast antennas are differently polarised.

32. The repeater station of any of claims 21 to 30, in which the broadcast antennas are not differently polarised.

33. The repeater station of any of claims 21 to 32, in which the broadcast antennas are spaced apart, so as to form an antenna array.

34. The repeater station claim 33, in which the antenna array is arranged such that, in use, a combined beam is formed, the repeater station being arranged such that the combined beam may be steered and/or shaped by varying the relative phase and/or amplitude of the transfer signals.

35. A base station comprising an input for a broadcast signal, an antenna arranged to broadcast using electromagnetic (EM) radiation the broadcast signal in use and two differently polarised transfer antennas for transmitting using EM radiation a transfer signal to a repeater station such that the repeater station can rebroadcast the broadcast signal.

36. The base station of claim 35, comprising two phase and/or amplitude modulators, the base station being arranged so as to apply the broadcast signal to the two phase and/or amplitude modulators, the phase and/or amplitude modulators being arranged so as to, in use, apply different shifts in amplitude and/or phase to the broadcast signal, and to output the respective resultant signals to respective ones of the transfer antennas.

37. The base station of claim 35 or claim 36, in which the transfer antennas are orthogonally polarised with respect to each other.

38. The base station of claim 36, in which the broadcast signal comprises two sub-signals, and in which the phase and/or amplitude modulators are arranged to apply different shifts to the two sub-signals.

40. A method of operating a base station—

repeater station pair, the pair comprising a base station arranged and a repeater station, the method comprising;

receiving at the base station a broadcast signal;

transmitting a transfer signal from the base station to the repeater station over a dual polarised electromagnetic (EM) radiation link;

broadcasting the broadcast signal from the repeater station using EM radiation.

41. The method of claim 40, in which the base station also broadcasts, using EM radiation, the broadcast signal.

42. The method of claim 40 or claim 41, in which the repeater station comprises two broadcast antennas on which the broadcast signal is transmitted and the repeater station receives two differently polarised versions of the transfer signal, the relative amplitude and phase of the broadcast signal as transmitted from the broadcast antennas depending upon the relative amplitude and phase of the two received transfer signal versions.

43. The method of claim 42, in which, as between the two received versions of the transfer signal on the one hand and the broadcast signal as transmitted on the two broadcast antennas on the other, one or both of the ratio of the amplitudes of the two signals and the phase difference between them is preserved.

44. The method of any of claims 40 to 43, comprising processing the received versions of the transfer signal in repeater station such that such that phase differences in the processed signals depends on the relative amplitudes of the versions of the transfer signal and the relative amplitudes of the processed signals depends upon the phase difference between the versions of the transfer signal, and transmitting the processed signals from the repeater station broadcast antennas.

45. The method of claim 44, in which the processing employs a hybrid network in the repeater station, such as a 2×

2 Butler matrix.

46. The method of claim 44 or claim 45, comprising amplifying each received transfer signal version in the repeater station before processing it.

47. The method of any of claims 40 to 46, in which the broadcast antennas on the repeater station are spaced apart, so as to form an antenna array, the broadcast signal may be of the form of a combined beam and in which by controlling, at the base station, the relative phases and amplitudes of the signals transmitted from the broadcast antennas on the repeater station, the method comprises steering and/or shaping the combined beam by varying the relative phase and/or amplitude of the transfer signal versions.

48. The method of any of claims 40 to 47, comprising applying at the base station different shifts in amplitude and/or phase to the broadcast signal, and transmitting the resultant signal as respective versions of the transfer signal.

49. The method of any of claims 40 to 48, in which the broadcast signal comprises two sub-signals, in which different phase and/or amplitude shifts are applied to the two sub-signals.

50. The method of claim 49, in which the shifts are such that each of the sub-signals is transmitted from a different broadcast antenna at the repeater station.