BASE STATION APPARATUS AND METHOD IN MOBILE COMMUNICATION SYSTEM

• US 20120002616A1
• Filed: 01/29/2010
• Published: 01/05/2012
• Est. Priority Date: 02/02/2009
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Ishii, Hiroyuki, Okubo, Naoto, Kiyoshima, Kohei
• Granted Patent: US 8,687,657 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365

Abstract

A base station apparatus determines which mode of a subframe bundling mode (second mode) and a non-bundling mode (first mode) should be used by a user apparatus for communication, and reports a determination result. In the first mode, RTT period is a first period, and each of transmission and retransmission of the signal is performed every 1 TTI. In the second mode, RTT period is a second period that is longer than the first period, and each of transmission and retransmission of the signal is performed every plurality of TTIs. A radio resource to be used for retransmission is determined according to a first frequency hopping pattern in the first mode, and is determined according to a second frequency hopping pattern that is different from the first frequency hopping pattern in the second mode.

Claims

1. A base station apparatus for use in a mobile communication system in which synchronization type automatic retransmission control is performed, comprising:

a determination unit configured to determine which mode of a subframe bundling mode and a non-bundling mode should be used by a user apparatus for communication;

a control signal generation unit configured to generate a control signal that includes information of a determination result; and

a transmission unit configured to transmit the control signal to the user apparatus,

wherein the control signal generation unit generates the control signal such that,

in the case of the non-bundling mode, a round trip time (RTT) from transmission of a signal by the user apparatus to retransmission of the signal is a first period, and each of transmission and retransmission of the signal is performed by a radio resource over a unit transmission period,

in the case of the subframe bundling mode, the round trip time is a second period longer than the first period, and each of transmission and retransmission of the signal is performed by a radio resource over a plurality of unit transmission periods, and

a radio resource to be used for retransmission by the user apparatus of the non-bundling mode is determined according to a first frequency hopping pattern, and a radio resource to be used for retransmission by the user apparatus of the subframe bundling mode is determined according to a second frequency hopping pattern that is different from the first frequency hopping pattern.

2. The base station apparatus as claimed in claim 1, wherein, in the first frequency hopping pattern, a radio resource used for transmission of a signal is separated from a radio resource used for retransmission of the signal by a predetermined bandwidth, and

in the second frequency hopping pattern, a bandwidth between a radio resource used for transmission of a signal and a reference frequency is the same as a bandwidth between a radio resource used for retransmission of the signal and the reference frequency.

3. The base station apparatus as claimed in claim 1, wherein, in the first frequency hopping pattern, a bandwidth between a radio resource used for transmission of a signal and a reference frequency is the same as a bandwidth between a radio resource used for retransmission of the signal and the reference frequency, and

in the second frequency hopping pattern, a radio resource used for transmission of a signal is separated from a radio resource used for retransmission of the signal by a predetermined bandwidth.

4. The base station apparatus as claimed in claim 1, wherein one radio resource occupies one subframe and a predetermined frequency bandwidth, and

the control signal generation unit generates the control signal such that a radio resource that becomes a start point of the first frequency hopping pattern or the second frequency hopping pattern is assigned to each user apparatus starting from a predetermined number of subframes in a low frequency side in order.

6. The base station apparatus as claimed in claim 2, wherein one radio resource occupies one subframe and a predetermined frequency bandwidth, and

the control signal generation unit generates the control signal such that a radio resource that becomes a start point of the first frequency hopping pattern or the second frequency hopping pattern is assigned to each user apparatus starting from a predetermined number of subframes in a low frequency side in order.

7. The base station apparatus as claimed in claim 2, wherein one radio resource occupies one subframe and a predetermined frequency bandwidth, and

the control signal generation unit generates the control signal such that a radio resource that becomes a start point of the first frequency hopping pattern or the second frequency hopping pattern is assigned to each user apparatus starting from a predetermined number of subframes in a low frequency side in order.

5. A method for use in a base station apparatus of a mobile communication system in which synchronization type automatic retransmission control is performed, comprising the steps of:

determining which mode of a subframe bundling mode and a non-bundling mode should be used by a user apparatus for communication;

generating a control signal that includes information of a determination result; and

transmitting the control signal to the user apparatus,

wherein the control signal is generated such that,

in the case of the non-bundling mode, a round trip time (RTT) from transmission of a signal by the user apparatus to retransmission of the signal is a first period, and each of transmission and retransmission of the signal is performed by a radio resource over a unit transmission period,

in the case of the subframe bundling mode, the round trip time is a second period longer than the first period, and each of transmission and retransmission of the signal is performed by a radio resource over a plurality of unit transmission periods, and

a radio resource to be used for retransmission by the user apparatus of the non-bundling mode is determined according to a first frequency hopping pattern, and a radio resource to be used for retransmission by the user apparatus of the subframe bundling mode is determined according to a second frequency hopping pattern that is different from the first frequency hopping pattern.