Communication system, method for the same and mobile station and base station used for the same

• US 9,008,679 B2
• Filed: 05/25/2007
• Issued: 04/14/2015
• Est. Priority Date: 06/14/2006
• Status: Active Grant

• Current Assignee: Lenovo Innovations Ltd Hong Kong (Lenovo Group Ltd.)
• Original Assignee: Lenovo Group Ltd.
• Inventors: Lee, Jinsock
• Primary Examiner(s): Magloire, Vladimir
• Assistant Examiner(s): Navar, Erica
• Application Number:
  US11/753,772
• Publication Number:
  US 20070293230A1
• Time in Patent Office: 2,881 Days
• Field of Search: 370/320, 370338-329, 370331-335, 370338-341, 455450-453, 455/509, 455560-561, 455/437
• US Class Current: 455/452.2
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

The present invention enables a high load to a mobile station and an uplink overhead to be reduced when a CQI measurement of a PRB needed for scheduling or adaptive modulation is informed of. At a base station, a set of PRBs (an active set) for which the measurements of CQIs are to be informed of is decided for each mobile station. Each mobile station measures only CQIs of the PRBs that form the active set designated by the base station and informs the base station of the measurements. That can reduce the load on the mobile station and also reduce the amount of information for informing the CQIs, thus, the uplink overhead can be also reduced.

Claims

1. A communication system comprising:

a mobile station which measures a communication channel quality of a wireless band obtained by dividing a downlink communication band into a plurality of wireless bands and informs a base station of the measurement via an uplink,

wherein said base station comprises;

a set managing unit that allocates a set comprising at least one wireless band whose quality is to be measured by said mobile station and sends, to said mobile station, a message which includes said at least one wireless band;

wherein said set managing unit is adapted to allocate to said mobile station a different set of one or more wireless bands to be measured by said mobile station, based on a request from said mobile station to add or delete one or more wireless bands from said set; and

wherein said mobile station comprises;

a requesting unit that requests to add a wireless band not included in the current set to said current set, upon an interference level of the wireless band being lower by a predetermined level than a maximum interference level or an average interference level in the current set.

2. The communication system according to claim 1, wherein said mobile station comprises:

a measurement unit that measures a communication channel quality of each wireless band that forms said set and informs said base station of the measurement.

3. The communication system according to claim 1, wherein said set managing unit that manages a wireless band that forms said set based on predetermined frequency planning between adjacent base stations.

4. The communication system according to claim 1, wherein said mobile station comprises:

a requesting unit that requests to add a wireless band not included in the current set to said current set, upon an interference level of the wireless band being lower than an average interference level in said current set.

5. The communication system according to claim 1, wherein said mobile station comprises:

a requesting unit that requests to add a wireless band not included in the current set to said current set, upon a SIR level of the wireless band being higher by a predetermined level than a level that is lower than a maximum SIR level or an average SIR level in said current set.

6. The communication system according to claim 1, wherein said mobile station comprises:

a requesting unit that requests to add a wireless band not included in the current set to said current set, upon an interference level (or a SIR level) of the wireless band being lower (or higher) than a predetermined interference level (or a predetermined SIR level).

7. The communication system according to claim 4, wherein a wireless band that can be requested to be added to said set is a wireless band within a predetermined range.

8. The communication system according to claim 1, wherein said mobile station comprises:

a requesting unit that requests to delete a wireless band in the current set from said current set, upon an interference level of the wireless band being higher than the interference level other than said current set.

9. The communication system according to claim 1, wherein said mobile station comprises:

a requesting unit that requests to delete a wireless band in the current set from said current set, upon an interference level of the wireless band being higher by a predetermined level than a level that is lower than a maximum interference level or an average interference level in said current set.

10. The communication system according to claim 1, wherein said mobile station comprises:

a requesting unit that requests to delete a wireless band in the current set from said current set, upon a SIR level of the wireless band being lower by a predetermined level than a level that is lower than a maximum SIR level or an average SIR level in said current set.

11. The communication system according to claim 1, wherein the mobile station comprises:

a requesting unit that requests to delete a wireless band in the current set from said current set, upon an interference level (or a SIR level) of the wireless band being higher (or lower) than a predetermined interference level (or a predetermined SIR level).

12. The communication system according to claim 1, wherein said set managing unit deletes a wireless band in the current set from said current set, upon a pilot signal of the wireless band being lower by a predetermined level than the maximum pilot signal in said current set.

13. A communication method in which a mobile station measures a communication channel quality of a wireless band obtained by dividing a downlink communication band into a plurality of wireless bands and informs a base station of the measurement via an uplink, comprising:

in said base station, allocating a set comprising at least one wireless band whose quality is to be measured by said mobile station;

sending, to said mobile station, a message which includes said at least one wireless band;

allocating to said mobile station a different set of one or more wireless bands to be measured by said mobile station based on a request from said mobile station to add or delete one or more wireless bands from said set; and

in said mobile station, requesting to add a wireless band other than the plurality of wireless bands forming the current set to said current set, upon an interference level of the wireless band being lower by a predetermined level than a level that is lower than a maximum interference level or an average interference level in said current set.

14. The communication method according to claim 13, further comprising:

in said mobile station,

measuring a communication channel quality of each wireless band that forms said set and informing said base station on the measurement.

15. The communication method according to claim 13, wherein said set managing step manages a wireless band that forms said set based on predetermined frequency planning between adjacent base stations.

16. The communication method according to claim 13, further comprising:

in said mobile station,

requesting to add a wireless band not included in the current set to said current set, upon an interference level of the wireless band being lower than an average interference level in said current set.

17. The communication method according to claim 13, further comprising:

in said mobile station,

requesting to add a wireless band not included in the current set to said current set, upon a SIR level of the wireless band being higher by a predetermined level than a level that is lower than a maximum SIR level or an average SIR level in said current set.

18. The communication method according to claim 13, further comprising:

in said mobile station,

requesting to add a wireless band not included in the current set to said current set, upon an interference level (or a SIR level) of the wireless band being lower (or higher) than a predetermined interference level (or a predetermined SIR level).

19. The communication method according to claim 13, wherein a wireless band that can be requested to be added to said set is a wireless band within a predetermined range.

20. The communication method according to claim 13, further comprising:

in said mobile station,

requesting to delete a wireless band in the current set from said current set, upon an interference level of the wireless band being higher than the interference level other than said current set.

21. The communication method according to claim 13, further comprising:

in said mobile station,

requesting to delete a wireless band in the current set from said current set, upon an interference level of the wireless band being higher by a predetermined level than a level that is lower than a maximum interference level or an average interference level in said current set.

22. The communication method according to claim 13, further comprising:

in said mobile station,

requesting to delete a wireless band in the current set from said current set, upon a SIR level of the wireless band being lower by a predetermined level than a level that is lower than a maximum SIR level or an average SIR level in said current set.

23. The communication method according to claim 13, further comprising:

in the mobile station,

requesting to delete a wireless band in the current set from said current set, upon an interference level (or a SIR level) of the wireless band being higher (or lower) than a predetermined interference level (or a predetermined SIR level).

24. The communication method according to claim 13, wherein said set managing step deletes a wireless band in the current set from said current set, upon a pilot signal of the wireless band being at a lower level than the level lower than the maximum pilot signal in said current set by a predetermined level.

25. A base station which is used in a mobile communication system in which a mobile station measures a communication channel quality of a wireless band obtained by dividing a downlink communication band into a plurality of wireless bands and informs said base station of the measurement via an uplink, comprising:

a receiving unit that receives said measurement, and a set managing unit that allocates a set comprising at least one wireless band whose quality is to be measured by said mobile station and sends, to said mobile station, a message which includes said at least one wireless band;

wherein said set managing unit is adapted to allocate to said mobile station a different set of one or more wireless bands to be measured by said mobile station, based on a request from said mobile station to add or delete one or more wireless bands from said set; and

wherein said set managing unit is adapted to add a wireless band not in the current set to said current set, upon a pilot signal of said current wireless band being lower by a predetermined level than a level that is lower than the maximum pilot signal in said current set.

26. The base station according to claim 25, wherein said set managing unit manages a wireless band that forms said set based on predetermined frequency planning between adjacent base stations.

27. The base station according to claim 25, wherein said set managing unit deletes a wireless band in the current set from said current set, upon a pilot signal of said current wireless band being lower by a predetermined level than a level that is lower than the maximum pilot signal in said current set.

28. A mobile station for measuring a communication channel quality of a wireless band obtained by dividing a downlink communication band into a plurality of wireless bands and informing a base station of the measurement via an uplink, comprising:

a measurement unit that measures the communication channel quality of at least one of said wireless bands whose channel quality is to be reported by said mobile station to the base station and that sends the base station a request to add or delete one or more wireless bands from a set of wireless bands whose channel quality is to be measured, based on a channel quality for said at least one of said wireless bands;

a managing unit adapted to be allocated a different set of one or more wireless bands to measure; and

a requesting unit that requests the base station to add a wireless band not included in the current set to said current set, upon an interference level of the wireless band being lower by a predetermined level than a maximum interference level or an average interference level in the current set.

29. The mobile station according to claim 28, comprising:

a requesting unit that requests the base station to add a wireless band not included in the current set to said current set, upon an interference level of the wireless band having an interference level lower than an average interference level in said current set.

30. The mobile station according to claim 28, comprising:

a requesting unit that requests the base station to add a wireless band not included in the current set to said current set, upon a SIR level of the wireless band being higher by a predetermined level than a level that is lower than a maximum SIR level or an average SIR level in said current set.

31. The mobile station according to claim 28, comprising:

a requesting unit that requests the base station to add a wireless band not included in the current set to said current set, upon an interference level (or a SIR level) of the wireless band being lower (or higher) than a predetermined interference level (or a predetermined SIR level).

32. The mobile station according to claim 29, wherein a wireless band that can be requested to be added to said current set is a wireless band within a predetermined range.

33. The mobile station according to claim 28, comprising:

a requesting unit that requests the base station to delete a wireless band in the current set from said current set, upon an interference level of the wireless band being higher than the interference level other than said current set.

34. The mobile station according to claim 28, comprising:

a requesting unit that requests the base station to delete a wireless band in the current set from said current set, upon an interference level of the wireless band being higher by a predetermined level than a level that is lower than a maximum interference level or an average interference level in said current set.

35. The mobile station according to claim 28, comprising:

a requesting unit that requests the base station to delete a wireless band in the current set from said current set, upon a SIR level of the wireless band being lower by a predetermined level than a level that is lower than a maximum SIR level or an average SIR level in said current set.

36. The mobile station according to claim 28, comprising:

a requesting unit that requests to delete a wireless band in the current set from said current set, upon an interference level (or a SIR level) of the wireless band being higher (or lower) than a predetermined interference level (or a predetermined SIR level).

37. A program embodied on a non-transitory computer readable medium for causing a computer to execute operations of a base station which is used in a mobile communication system in which a mobile station measures a communication channel quality of a wireless band obtained by dividing a downlink communication band into a plurality of wireless bands and informs said base station of the measurement via an uplink, said operations comprising:

receiving said measurement;

allocating a set which comprises at least one wireless band whose quality is to be measured by said mobile station;

sending, to said mobile station, a message which includes said at least one wireless band;

allocating to said mobile station a different set of one or more wireless bands to be measured by said mobile station based on a request from said mobile station to add or delete one or more wireless bands from said set; and

adding a wireless band not included in the current set to said current set, upon a pilot signal of said current wireless band being lower by a predetermined level than a level that is lower than the maximum pilot signal in said current set.