Base station apparatus
A base station apparatus capable of preventing occurrence of a communication delay when performing an inter-cell interference control using an ABS is provided. The base station apparatus is capable of performing an inter-cell interference control by setting an ABS pattern with one cycle of a predetermined number of subframes, and when the ABS pattern is to be switched, changes an MCS (Modulation and Coding Scheme) index value to be determined by an adaptive modulation control, for a communication within a predetermined period of time on or before a switching time of the switching, with respect to a subframe in which a communication with a mobile station apparatus is allowed before switching the ABS pattern.
1. A base station apparatus capable of performing an inter-cell interference control by setting an ABS (Almost Blank Subframe) pattern with one cycle of a predetermined number of subframes, the base station apparatus comprising:
means of:
changing an MCS (Modulation and Coding Scheme) index value to a lower value, the MCS index value being determined by an adaptive modulation control, when the ABS pattern is to be switched, with respect to a subframe in which a communication with a mobile station apparatus is allowed before switching the ABS pattern and an allocation of radio communication is not performed in a retransmission control after switching the ABS pattern; and
using the changed MCS index value for the specific subframe in an initial transmission or a retransmission of a data transmission that is performed before switching the ABS pattern,
wherein, based on a number of remaining transmittable times of at least the retransmission of the data transmission for the specific subframe before switching the ABS pattern, the MCS index value determined by the adaptive modulation control is changed to a lower value as the number of remaining transmittable times is smaller, and
wherein the changed MCS index value is used for the specific subframe before switching the ABS pattern.
2. The base station apparatus according to claim 1 ,
wherein the MCS index value is based on the number of remaining transmittable times of the initial transmission and the retransmission of the data transmission for the specific subframe before switching the ABS pattern.
3. The base station apparatus according to claim 1 ,
wherein a retransmission control by an HARQ (Hybrid Automatic Repeat reQuest) is applied, and
wherein, when a block error occurs in the initial transmission of the data transmission and a HARQ retransmission of the data transmission is performed before switching the ABS pattern, the MCS index value determined by the adaptive modulation control is changed to a lower value when performing an HARQ retransmission, with respect to a specific subframe in which the communication with the mobile station apparatus is allowed before switching the ABS pattern and an allocation of radio communication is not performed in an HAQR retransmission control after switching the ABS pattern, and the changed MCS index value is used for the specific subframe before switching the ABS pattern.
4. The base station apparatus according to claim 1 ,
wherein the MCS index value is based on the number of remaining transmittable times of the retransmission of the data transmission for the specific subframe before switching the ABS pattern, and wherein the number of remaining transmittable times does not include the initial transmission.
5. The base station apparatus according to claim 1 ,
wherein, when a MIMO (Multiple Input Multiple Output) for transmitting two or more streams is applied, with respect to the specific subframe, an MCS index value determined by the adaptive modulation control is changed to a different value for each rank that is the number of transmission streams, and
wherein the changed MCS index value is used for the specific subframe before switching the ABS pattern.
6. The base station apparatus according to claim 1 ,
wherein the MCS index value to be determined by the adaptive modulation control is changed to an MCS index value by which the least error occurs.
7. The base station apparatus according to claim 1 ,
wherein the communication in which the MCS index value is changed is an uplink communication, a downlink communication, or both of them.
8. For a base station apparatus capable of performing an inter-cell interference control by setting an ABS (Almost Blank Subframe) pattern with one cycle of a predetermined number of subframes, a method comprising:
changing an MCS (Modulation and Coding Scheme) index value to a lower value, the MCS index value being determined by an adaptive modulation control, when the ABS pattern is to be switched, with respect to a subframe in which a communication with a mobile station apparatus is allowed before switching the ABS pattern and an allocation of radio communication is not performed in a retransmission control after switching the ABS pattern; and
using the changed MCS index value for the specific subframe in an initial transmission or a retransmission of a data transmission that is performed before switching the ABS pattern,
wherein, based on the number of remaining transmittable times of the initial transmission and the retransmission of the data transmission for the specific subframe before switching the ABS pattern, the MCS index value determined by the adaptive modulation control is changed to a lower value as the number of remaining transmittable times is smaller, and
wherein the changed MCS index value is used for the specific subframe before switching the ABS pattern.
9. The method according to claim 8 ,
wherein the MCS index value is based on the number of remaining transmittable times of the initial transmission and the retransmission of the data transmission for the specific subframe before switching the ABS pattern.
10. The method according to claim 8 ,
wherein a retransmission control by an HARQ (Hybrid Automatic Repeat reQuest) is applied, and
wherein, when a block error occurs in the initial transmission of the data transmission and a HARQ retransmission of the data transmission is performed before switching the ABS pattern, the MCS index value to be determined by the adaptive modulation control is changed to a lower value when performing an HARQ retransmission, with respect to a specific subframe in which the communication with the mobile station apparatus is allowed before switching the ABS pattern and an allocation of radio communication is not performed in an HAQR retransmission control after switching the ABS pattern, and the changed MCS index value is used for the specific subframe before switching the ABS pattern.
11. The method according to claim 8 ,
wherein the MCS index value is based on the number of remaining transmittable times of the retransmission of the data transmission for the specific subframe before switching the ABS pattern, and wherein the number of remaining transmittable times does not include the initial transmission.
12. The method according to claim 8 ,
wherein, when a MIMO (Multiple Input Multiple Output) for transmitting two or more streams is applied, with respect to the specific subframe, an MCS index value determined by the adaptive modulation control is changed to a different value for each rank that is the number of transmission streams, and
wherein the changed MCS index value is used for the specific subframe before switching the ABS pattern.
13. The method according to claim 8 ,
wherein the MCS index value to be determined by the adaptive modulation control is changed to an MCS index value by which the least error occurs.
14. The method according to claim 8 ,
wherein the communication in which the MCS index value is changed is an uplink communication, a downlink communication, or both of them.