MOBILE RADIO TERMINAL AND MOBILE COMMUNICATION SYSTEM

• US 20090170442A1
• Filed: 07/02/2008
• Published: 07/02/2009
• Est. Priority Date: 12/27/2007
• Status: Active Grant

• Current Assignee: Godo Kaisha IP Bridge 1 (IP Bridge, Inc.)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Terabe, Shigeo, ASANUMA, Yutaka
• Granted Patent: US 8,023,900 B2
• Time in Patent Office: Days
• US Class Current: 455/67.110
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0029 Reduction of the amount of signalling, e.g. retention of useful signalling or differential signalling power control H04W52/04
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals

Abstract

Each of a mobile station and a base station stores a Wideband CQI table and a Subband CQI table. At the mobile station, a control unit transmits a CQI report value indicating Wideband CQI, and an index (Index S) indicating a differential value of a Diff reference value based on the CQI report value and Subband CQI, on the basis of the tables. In addition, the control unit makes the Diff reference value variable to prevent an expression amount of the index from being damaged if the Wideband CQI report value is in a range close to an upper lit or a lower limit of the Wideband CQI table.

Claims

1. A mobile radio terminal establishing radio communications with a base station apparatus accommodated in a network, the mobile radio terminal comprising:

a Wideband measuring unit which measures reception quality of a Wideband;

a Subband measuring unit which measures reception quality of each of a plurality of Subbands included in the Wideband;

a first determining unit which determines a Wideband report value within a preset first range, in accordance with the measurement result of the Wideband measuring unit;

a second determining unit which determines a reference value having a preset first referential difference from the Wideband report value, and which determines a reference value having a second referential difference smaller than the first referential difference if the Wideband report value is a value in a preset upper limit domain;

a third determining unit which determines an index value corresponding to a difference between the referential value and the Subband reception quality, within a preset second range; and

a transmitting unit which transmits the Wideband report value and the index value to the base station apparatus.

2. The mobile radio terminal according to claim 1, wherein the second determining unit sets the first referential difference to be a positive value.

3. The mobile radio terminal according to claim 1, wherein the third determining unit sets number of index values superior in reception quality to the referential value to be more than number of index values inferior in reception quality.

4. A mobile radio terminal establishing radio communications with a base station apparatus accommodated in a network, the mobile radio terminal comprising:

a Wideband measuring unit which measures reception quality of a Wideband;

a Subband measuring unit which measures reception quality of each of a plurality of Subbands included in the Wideband;

a first determining unit which determines a Wideband report value within a preset first range, in accordance with the measurement result of the Wideband measuring unit;

a second determining unit which determines a reference value having a preset first referential difference from the Wideband report value, and which determines a reference value having a second referential difference greater than the first referential difference if the Wideband report value is a value in a preset lower limit domain;

a third determining unit which determines an index value corresponding to a difference between the referential value and the Subband reception quality, within a preset second range; and

a transmitting unit which transmits the Wideband report value and the index value to the base station apparatus.

5. The mobile radio terminal according to claim 4, wherein if the Wideband report value is a value in a preset upper limit domain, the second determining unit determines a reference value having a third referential difference smaller than the first referential difference.

6. The mobile radio terminal according to claim 5, wherein the second determining unit sets number of Wideband report values falling within the upper limit domain to be more than number of Wideband report values falling within the lower limit domain.

7. The mobile radio terminal according to claim 4, wherein the second determining unit sets the first referential difference to be a positive value.

8. The mobile radio terminal according to claim 4, wherein the third determining unit sets number of index values superior in reception quality to the referential value to be more than number of index values inferior in reception quality.

9. A mobile communication system in which a base station apparatus accommodated in a network establishes radio communications with a mobile radio terminal, the mobile radio terminal comprising:

a Wideband measuring unit which measures reception quality of a Wideband;

a Subband measuring unit which measures reception quality of each of a plurality of Subbands included in the Wideband;

a first determining unit which determines a Wideband report value within a preset first range, in accordance with the measurement result of the Wideband measuring unit;

a second determining unit which determines a reference value having a preset first referential difference from the Wideband report value, and which determines a reference value having a greater second referential difference than the first referential difference if the Wideband report value is a value in a preset lower limit domain and determines a reference value having a second referential difference smaller than the first referential difference if the Wideband report value is a value in a preset upper limit domain;

a third determining unit which determines an index value corresponding to a difference between the referential value and the Subband reception quality, within a preset second range; and

a transmitting unit which transmits the Wideband report value and the index value to the base station apparatus,

the base station apparatus comprising;

a receiving unit which receives the Wideband report value and the index value from the mobile radio terminal;

a first detecting unit which detects the reception quality of the Wideband in accordance with the Wideband report value;

a second detecting unit which detects the reception quality of the Subbands, in accordance with the Wideband report value and the index value; and

a determining unit which determines a modulation scheme of a transmission signal for the mobile radio terminal, in accordance with the reception quality detected by the first detecting unit and the reception quality detected by the second detecting unit.

10. A mobile radio terminal establishing radio communications with a base station apparatus accommodated in a network, the mobile radio terminal comprising:

a Wideband measuring unit which measures reception quality of a Wideband;

a Subband measuring unit which measures reception quality of each of a plurality of Subbands included in the Wideband;

a determining unit which determines a Wideband report value within a preset first range, in accordance with the measurement result of the Wideband measuring unit;

a first memory unit which stores a Wideband quality table associating a reference value having a preset first referential difference with the Wideband report value in a preset standard domain, and associating a reference value having a second referential difference smaller than the first referential difference with the Wideband report value of an upper limit domain greater than the standard domain;

a second memory unit which stores a Subband quality table associating a difference between the reference value and the Subband reception quality, with an index value in a preset second range;

a detecting unit which detects a referential value associated with the Wideband report value by referring to the Wideband quality table, and detects an index value associated with a difference between the reference value and the Subband reception quality; and

a transmitting unit which transmits the index value detected by the detecting unit and the Wideband report value to the base station apparatus.

11. The mobile radio terminal according to claim 10, wherein the first memory unit stores a Wideband quality table setting the first referential difference to be a positive value.

12. The mobile radio terminal according to claim 10, wherein the second memory unit stores a Subband quality table setting number of index values superior in reception quality to the referential value to be more than number of index values inferior in reception quality.

13. A mobile radio terminal establishing radio communications with a base station apparatus accommodated in a network, the mobile radio terminal comprising:

a Wideband measuring unit which measures reception quality of a Wideband;

a Subband measuring unit which measures reception quality of each of a plurality of Subbands included in the Wideband;

a determining unit which determines a Wideband report value within a preset first range, in accordance with the measurement result of the Wideband measuring unit;

a first memory unit which stores a Wideband quality table associating a reference value having a preset first referential difference with the Wideband report value in a preset standard domain, and associating a reference value having a second referential difference greater than the first referential difference with the Wideband report value of a lower limit domain smaller than the standard domain;

a second memory unit which stores a Subband quality table associating a difference between the reference value and the Subband reception quality, with an index value in a preset second range;

a detecting unit which detects a referential value associated with the Wideband report value by referring to the Wideband quality table, and detects an index value associated with a difference between the reference value and the Subband reception quality; and

a transmitting unit which transmits the index value detected by the detecting unit and the Wideband report value to the base station apparatus.

14. The mobile radio terminal according to claim 13, wherein the first memory unit stores a Wideband quality table associating the reference value having the preset first referential difference with the Wideband report value in the preset standard domain, associating a reference value having the second referential difference greater than the first referential difference with the Wideband report value of the lower limit domain smaller than the standard domain, and associating a reference value having a third referential difference smaller than the first referential difference with the Wideband report value of the upper limit domain greater than the standard domain.

15. The mobile radio terminal according to claim 14, wherein the first memory unit stores a Wideband quality table setting number of Wideband report values falling within the upper limit domain to be more than number of Wideband report values falling within the lower limit domain.

16. The mobile radio terminal according to claim 13, wherein the first memory unit stores a Wideband quality table setting the first referential difference to be a positive value.

17. The mobile radio terminal according to claim 13, wherein the second memory unit stores a Subband quality table setting number of index values superior in reception quality to the referential value to be more than number of index values inferior in reception quality.

18. A mobile communication system in which a base station apparatus accommodated in a network establishes radio communications with a mobile radio terminal, the mobile radio terminal comprising:

a Wideband measuring unit which measures reception quality of a Wideband;

a Subband measuring unit which measures reception quality of each of a plurality of Subbands included in the Wideband;

a determining unit which determines a Wideband report value within a preset first range, in accordance with the measurement result of the Wideband measuring unit;

a first memory unit which stores a Wideband quality table associating a reference value having a preset first referential difference with the Wideband report value in a preset standard domain, associating a reference value having a second referential difference greater than the first referential difference with the Wideband report value of a lower limit domain smaller than the standard domain, and associating a reference value having a third referential difference smaller than the first referential difference with the Wideband report value in an upper limit domain greater than the standard domain;

a second memory unit which stores a Subband quality table associating a difference between the reference value and the Subband reception quality, with an index value thereof;

a first detecting unit which detects a referential value associated with the Wideband report value by referring to the Wideband quality table, and detects an index value associated with the difference between the reference value and the Subband reception quality from the Subband quality table; and

a transmitting unit which transmits the index value detected by the first detecting unit and the Wideband report value to the base station apparatus,

the base station apparatus comprising;

a receiving unit which receives the Wideband report value and the index value from the mobile radio terminal;

a second detecting unit which detects the reception quality of the Wideband in accordance with the Wideband report value;

a third detecting unit which detects the reception quality of the Subbands, in accordance with the Wideband report value and the index value; and

a determining unit which determines a modulation scheme of a transmission signal for the mobile radio terminal, in accordance with the reception quality detected by the second detecting unit and the reception quality detected by the third detecting unit.

19. A base station apparatus establishing radio communications with a mobile radio terminal, comprising:

a receiving unit which receives a Wideband report value indicating Wideband reception quality, and an index value indicating reception quality of a plurality of Subbands included in the Wideband as a relative value to the Wideband report value, from the mobile radio terminal;

a first detecting unit which detects the Wideband reception quality in a preset first range, in accordance with the Wideband report value;

a first determining unit which determines the Wideband report value and a reference value having a preset first referential difference, and determines a reference value having a second referential difference smaller than the first referential difference if the Wideband report value is a value of a preset upper limit domain;

a second detecting unit which detects the Subband reception quality in a preset second range, in accordance with the reference value and the index value; and

a second determining unit which determines a modulation scheme of a transmission signal for the mobile radio terminal, in accordance with the reception quality detected by the first detecting unit and the reception quality detected by the second detecting unit.

20. The base station apparatus according to claim 19, wherein the first determining unit sets the first referential difference to be a positive value.

21. The base station apparatus according to claim 19, wherein the second detecting unit sets number of index values superior in reception quality to the referential value to be more than number of index values inferior in reception quality.

22. A base station apparatus establishing radio communications with a mobile radio terminal, comprising:

a receiving unit which receives a Wideband report value indicating Wideband reception quality, and an index value indicating reception quality of a plurality of Subbands included in the Wideband as a relative value to the Wideband report value, from the mobile radio terminal;

a first detecting unit which detects the Wideband reception quality in a preset first range, in accordance with the Wideband report value;

a first determining unit which determines the Wideband report value arid a reference value having a preset first referential difference, and determines a reference value having a second referential difference greater than the first referential difference if the Wideband report value is a value of a preset lower limit domain;

a second detecting unit which detects the Subband reception quality in a preset second range, in accordance with the reference value and the index value; and

a second determining unit which determines a modulation scheme of a transmission signal for the mobile radio terminal, in accordance with the reception quality detected by the first detecting unit and the reception quality detected by the second detecting unit.

23. The base station apparatus according to claim 22, wherein the first determining unit determines the Wideband report value and the reference value having the preset first referential difference, and determines a reference value having a second referential difference greater than the first referential difference if the Wideband report value is a value of a preset lower limit domain and determines a reference value having a third referential difference smaller than the first referential difference if the Wideband report value is a value of a preset upper limit domain.

24. The base station apparatus according to claim 23, wherein the first determining unit sets number of Wideband report values falling within the upper limit domain to be more than number of Wideband report values falling within the lower limit domain.

25. The base station apparatus according to claim 22, wherein the first determining unit sets the first referential difference to be a positive value.

26. The base station apparatus according to claim 22, wherein the second detecting unit sets number of index values superior in reception quality to the referential value to be more than number of index values inferior in reception quality.