Air-interface efficiency in wireless communication systems

• US 6,690,936 B1
• Filed: 10/31/2000
• Issued: 02/10/2004
• Est. Priority Date: 10/31/2000
• Status: Expired due to Term

• Current Assignee: Lenovo Innovation Company Limited Hong Kong (Lenovo Group Ltd.)
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Lundh, Peter
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): LE, DANH C
• Application Number:
  US09/702,516
• Time in Patent Office: 1,197 Days
• Field of Search: 455/436, 455/438, 455/439, 455/442, 455/443, 455/444, 370/331, 370/332, 370/335, 370/342, 370/441
• US Class Current: 455/436
• CPC Class Codes: H04B 7/02 Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas RAKE receivers H04B1/7115
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/08 at the receiving station
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 36/28 involving a plurality of connections, e.g. multi-call or multi-bearer connections

Abstract

A greater variety of frequency combinations may be utilized in multiple situations, including, by way of example but not limitation, hard handovers, soft handovers, macrodiversity, etc. Soft handovers, for example, may be executed between two base stations (BSs) with respect to a mobile station (MS) in which the uplink (UL) and downlink (DL) frequency pairs used to communicate with each base station differ from each other. For instances, only the UL carrier channel, only the DL carrier channel, or both the UL and the DL carrier channels may differ for the respective communications between the MS and the respective BSs. In the first two cases in which only one carrier channel differs, variable duplex distance (VDD) is implemented. In the third case in which both carrier channels differ, constant duplex distance (CDD) is implemented. In another embodiment of the present invention, a hard handover that relies on a VDD implementation is effectuated by changing only one of the UL and the DL carrier channels in the handover process.

Claims

1. A method in a wireless communications system for improving air-interface efficiency, comprising the steps of:

engaging in a first communication between a remote communication station and a first communication station using a first carrier set;

beginning a second communication between said remote communication station and a second communication station using a second carrier set;

wherein said first carrier set comprises a first uplink carrier and a first downlink carrier, and said second carrier set comprises a second uplink carrier and said first downlink carrier;

wherein said first carrier set is different from said second carrier set; and

wherein, for the case of communications being handed over to said second carrier set by means of a hard handover, one carrier of the first carrier set and one carrier of the second carrier set have substantially identical carrier frequencies.

2. The method according to claim 1, wherein the wireless communications system operates in accordance with at least one of a code division multiple access (CDMA) technology, a time division multiple access (TDMA) technology, and the Global System for Mobile Communications (GSM) standard.

3. The method according to claim 1, wherein said first communication station is associated with a first cell and said second communication station is associated with a second cell.

4. The method according to claim 1, further comprising:

ceasing said first communication between said remote communication station and said first communication station; and

continuing said second communication between said remote communication station and said second communication station using said second carrier set.

5. The method according to claim 4, whereby a handover involving variable duplex distance is thereby effectuated.

6. The method according to claim 1, wherein the hard handover comprises:

terminating said first communication and thereby interrupting an information dialogue involving said remote communication station after a first data point and before a second data point of said information dialogue; and

initiating the second communication between said remote communication station and the second communication station using the second carrier set, said second communication including said second data point of said information dialogue.

7. The method according to claim 6, whereby a hard handover involving variable duplex distance is thereby effectuated.

8. The method according to claim 1, further comprising:

maintaining said first communication between said remote communication station and said first communication station using said first carrier set and said second communication between said remote communication station and said second communication station using said second carrier set, said first communication and said second communication containing substantially identical information.

9. The method according to claim 8, wherein said first communication and said second communication contain substantially identical information substantially contemporaneously.

10. The method according to claim 8, whereby a soft handover is thereby effectuated.

11. The method according to claim 10, wherein said first carrier set comprises a first uplink carrier and a first downlink carrier, and said second carrier set comprises a second uplink carrier and a second downlink carrier.

12. A wireless communications system for improving air-interface efficiency, comprising:

means for engaging in a first communication between a remote communication station and a first communication station using a first carrier set;

means for beginning a second communication between said remote communication station and a second communication station using a second carrier set;

wherein said first carrier set comprises a first uplink carrier and a first downlink carrier, and said second carrier set comprises a second uplink carrier and said first downlink carrier;

wherein said first carrier set is different from said second carrier set; and

wherein, for the case of communications being handed over to said second carrier set by means of a hard handover, one carrier of the first carrier set and one carrier of the second carrier set have substantially identical carrier frequencies.

13. The wireless communications system according to claim 12, wherein the wireless communications system operates in accordance with at least one of a code division multiple access (CDMA) technology, a time division multiple access (TDMA) technology, and the Global System for Mobile Communications (GSM) standard.

14. The wireless communications system according to claim 12, wherein said first communication station is associated with a first cell and said second communication station is associated with a second cell.

15. The wireless communications system according to claim 12, further comprising:

means for ceasing said first communication between said remote communication station and said first communication station; and

means for continuing said second communication between said remote communication station and said second communication station using said second carrier set.

16. The wireless communications system according to claim 15, wherein the means are means for effectuating handover involving variable duplex distance.

17. The wireless communication system according to claim 12, wherein the hard handover comprises:

terminating said first communication and thereby interrupting said information dialogue after a first data point and before a second data point of said information dialogue; and

initiating a second communication between said remote communication station and a second communication station using a second carrier set, said second carrier set including one, but not both, of said uplink carrier and said downlink carrier, said second communication including said second data point of said information dialogue.

18. The wireless communications system according to claim 17, wherein the means are means for effectuating a variable duplex distance hard handoff so that said remote communication station is in wireless communication with said second communication station using a second carrier set.

19. The wireless communications system according to claim 12, further comprising:

means for maintaining said first communication between said remote communication station and said first communication station using said first carrier set and said second communication between said remote communication station and said second communication station using said second carrier set, said first communication and said second communication containing substantially identical information.

20. The wireless communications system according to claim 19, wherein said first communication and said second communication contain substantially identical information substantially contemporaneously.

21. The wireless communications system according to claim 19, wherein the means are means for effectuating soft handover.

22. The wireless communications system according to claim 21, wherein said first carrier set comprises a first uplink carrier and a first downlink carrier, and said second carrier set comprises a second uplink carrier and a second downlink carrier.

23. An arrangement for improving air-interface efficiency, comprising:

a transceiving unit, said transceiving unit adapted for transmitting and receiving using a plurality of carriers;

a channel data structure, said channel data structure including a plurality of carrier sets;

a carrier effectuator, said carrier effectuator coupled to said transceiving unit and said channel data structure, said carrier effectuator adapted for selecting at least one carrier set from said plurality of carrier sets of said channel data structure and for controlling said transceiving unit to utilize said at least one carrier set;

wherein said first carrier set comprises a first uplink carrier and a first downlink carrier, and said second carrier set comprises a second uplink carrier and said first downlink carrier;

wherein said transceiving unit transmits substantially contemporaneously using said first carrier set and said second carrier set, said first carrier set differing from said second carrier set; and

wherein for the case of communications being handed over to said second carrier set by means of a hard handover;

one carrier of the first carrier set and one carrier of the second carrier set have substantially identical carrier frequencies.

24. The arrangement according to claim 23, whereby a handover involving variable duplex distance is thereby effectuated.

25. The arrangement according to claim 23, wherein the arrangement operates in accordance with at least one of a code division multiple access (CDMA) technology, a time division multiple access (TDMA) technology, and the Global System for Mobile Communications (GSM) standard.

26. The arrangement according to claim 23, wherein the hard handover comprises:

terminating said first communication and thereby interrupting an information dialogue involving said remote communication station after a first data point and before a second data point of said information dialogue; and

initiating the second communication between said remote communication station and the second communication station using the second carrier set, said second communication including said second data point of said information dialogue.

27. The arrangement according to claim 26, whereby a hard handover involving variable duplex distance is thereby effectuated.

28. The arrangement according to claim 23, wherein the arrangement comprises a mobile station.

29. The arrangement according to claim 23, wherein the arrangement comprises a base station.

30. The arrangement according to claim 23, wherein said transceiving unit comprises at least two transceivers.

31. The arrangement according to claim 23, wherein said channel data structure is stored in a memory.

32. The arrangement according to claim 23, wherein said carrier effectuator comprises, at least partly, software instructions code.

33. The arrangement according to claim 23, wherein said carrier effectuator comprises, at least partly, a data processor.

34. The arrangement according to claim 23, wherein said transceiving unit transmits substantially identical information during a soft handover procedure substantially contemporaneously using said first carrier set and said second carrier set.

35. The arrangement according to claim 34, wherein said first carrier set comprises a first uplink carrier and a first downlink carrier, and said second carrier set comprises a second uplink carrier and a second downlink carrier.

36. An arrangement for improving air-interface efficiency, comprising:

a transceiving unit, said transceiving unit adapted for transmitting and receiving using a plurality of carriers;

a channel data structure, said channel data structure including a plurality of carrier sets, a first carrier set of said plurality of carrier sets including a first carrier and a second carrier, a second carrier set of said plurality of carrier sets including said first carrier and a third carrier;

a carrier effectuator, said carrier effectuator coupled to said transceiving unit and said channel data structure, said carrier effectuator adapted for selecting at least one carrier set from said plurality of carrier sets of said channel data structure and for controlling said transceiving unit to utilize said at least one carrier set;

and wherein said transceiving unit is further adapted for transceiving using said first carrier set prior to or during a handover and for transceiving using said second carrier set after or during a handover.

37. The arrangement according to claim 36, wherein the arrangement comprises a mobile station.

38. The arrangement according to claim 36, wherein the arrangement comprises a base station.

39. The arrangement according to claim 36, wherein the arrangement operates in accordance with at least one of a code division multiple access (CDMA) technology, a time division multiple access (TDMA) technology, and the Global System for Mobile Communications (GSM) standard.

40. The arrangement according to claim 36, wherein said handover is a hard handover.

41. The arrangement according to claim 36, wherein said handover is a soft handover.

42. The arrangement according to claim 36, wherein said first carrier is an uplink carrier and said second and third carriers are downlink carriers.

43. The arrangement according to claim 36, wherein said first carrier is a downlink carrier and said second and third carriers are uplink carriers.

44. The arrangement according to claim 36, wherein said transceiving unit is further adapted for transceiving using both said first carrier set and said second carrier set during a handover.

45. A method in a wireless communications system for improving air-interface efficiency, comprising the steps of:

engaging in a first communication between a remote communication station and a first communication station using a first carrier set;

beginning a second communication between said remote communication station and a second communication station using a second carrier set;

wherein said first carrier set comprises a first uplink carrier and a first downlink carrier, and said second carrier set comprises said first uplink carrier and a second downlink carrier;

wherein said first carrier set is different from said second carrier set; and

wherein, for the case of communications being handed over to said second carrier set by means of a hard handover, one carrier of the first carrier set and one carrier of the second carrier set have substantially identical carrier frequencies.

46. A wireless communications system for improving air-interface efficiency, comprising:

means for engaging in a first communication between a remote communication station and a first communication station using a first carrier set;

means for beginning a second communication between said remote communication station and a second communication station using a second carrier set;

wherein said first carrier set comprises a first uplink carrier and a first downlink carrier, and said second carrier set comprises a second uplink carrier and a second downlink carrier;

wherein said first carrier set is different from said second carrier set; and

wherein, for the case of communications being handed over to said second carrier set by means of a hard handover, one carrier of the first carrier set and one carrier of the second carrier set have substantially identical carrier frequencies.

47. An arrangement for improving air-interface efficiency, comprising:

a transceiving unit, said transceiving unit adapted for transmitting and receiving using a plurality of carriers;

a channel data structure, said channel data structure including a plurality of carrier sets;

a carrier effectuator, said carrier effectuator coupled to said transceiving unit and said channel data structure, said carrier effectuator adapted for selecting at least one carrier set from said plurality of carrier sets of said channel data structure and for controlling said transceiving unit to utilize said at least one carrier set;

wherein said first carrier set comprises a first uplink carrier and a first downlink carrier, and said second carrier set comprises said first uplink carrier and a second downlink carrier;

wherein said transceiving unit transmits substantially contemporaneously using said first carrier set and said second carrier set, said first carrier set differing from said second carrier set; and

wherein for the case of communications being handed over to said second carrier set by means of a hard handover;

one carrier of the first carrier set and one carrier of the second carrier set have substantially identical carrier frequencies.