# US 8,275,565 B2 · Radio communication apparatus and radio communication method used in mobile communication system

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- Number: US 8,275,565 B2
- Document ID: US8275565B2
- Status: Granted
- Kind: B2
- Application number: 12/305,325
- Filed: 2007-06-15
- Published: 2010-12-09
- Granted: 2012-09-25
- Earliest claimed: 2006-06-20
- Assignees: Ntt Docomo, Inc.
- Inventors: Anil Umesh; Takehiro Nakamura
- Web page: https://patentgrep.com/patent/US8275565B2

## CPC

- H04L 1/0083: {Formatting with frames or packets; Protocol or part of protocol for error control}
- H04L 1/1671: {the supervisory signal being transmitted together with control information}
- H04L 1/1812: Hybrid protocols; Hybrid automatic repeat request [HARQ]
- H04L 2001/125: {Arrangements for preventing errors in the return channel}
- H04W 88/02: Terminal devices
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

A disclosed radio communication apparatus includes a unit receiving a broadcast channel including a system frame number (SFN), a control channel including a process number (Proc) and a new data identification, and a user data channel including a sequence number; a unit detecting whether a received first packet includes an error and reporting the detection result indicating ACK or NACK to a transmitter side; a unit detecting whether the control channel has not been correctly received in the past based on the process number and the new packet identification information of a second packet transmitted after the first packet; and a unit reporting an indicator including the SFN at which the second packet is transmitted to the transmitter side, so that a packet is re-transmitted, the packet being transmitted to the radio communication apparatus by a preceding SFN that precedes an SFN at which the second packet is transmitted.

## Claims

### Claim 1

A radio communication apparatus used in a mobile communication system, comprising:
a unit configured to receive a user data channel including a sequence number and determining a system frame number, a process number, and new packet identification information;
a unit configured to detect whether a received first packet includes an error and transmitting a report of the detected result indicating an affirmative or a negative result to a transmitter side;
a unit configured to detect whether a control channel has not been correctly received in the past based on the process number and the new packet identification information of a second packet transmitted after the first packet;
a unit configured to generate an indicator consisting of the system frame number corresponding to a latest control channel having been correctly received; and
a unit configured to report the system frame number of the indicator at which the second packet is transmitted, so that the transmitter side specifies the sequence number of a packet to be re-transmitted based on the system frame number, the packet being transmitted to the radio communication apparatus by a preceding system frame number preceding the reported system frame number at which the second packet is transmitted, wherein
a transmission timing at which the control channel has not been correctly received is identified based on the preceding system frame number.

### Claim 2

A radio communication apparatus used in a mobile communication system, comprising:
a unit configured to transmit a user data channel including a sequence number;
a unit configured to receive an error detection result indicating an affirmative or a negative result with respect to a transmitted first packet;
a unit configured to receive, after a receiving side detects that a control channel has not been correctly received in the past based on a process number and new packet identification information of a second packet transmitted first after the first packet is transmitted, an indicator when the second packet is transmitted, the indicator consisting of a system frame number corresponding to a latest control channel having been correctly received;
a unit configured to store attribute information including the sequence frame number and the sequence number corresponding to transmitted packets; and
a unit configured to specify the sequence number of a packet that has not been correctly transmitted in the past based on the attribute information by using a system frame number preceding the system frame number at which the second packet is transmitted and re-transmit the packet.

### Claim 3

A radio communication method used in a mobile communication system, comprising:
a step of transmitting a user data channel including a sequence number from a transmitter to a receiver and determining a system frame number, a process number, and new packet identification information by the receiver;
a step of detecting whether a first packet received by the receiver includes an error and transmitting a report of the detected result indicating an affirmative or a negative result to a transmitter side;
a step of detecting whether a control channel has not been correctly received in the past based on the process number and the new packet identification information of a second packet transmitted after the first packet;
a step of generating an indicator consisting of the system frame number corresponding to a latest control channel having been correctly received;
a step of reporting the system frame number of the indicator at which the second packet is transmitted to the transmitter side;
a step of storing attribute information including the sequence frame number and the sequence number corresponding to the transmitted packets;
a step of specifying the sequence number of a packet that has not been correctly transmitted in the past based on the attribute information by using a system frame number preceding the reported system frame number at which the second packet is transmitted and retransmitting the packet, wherein
a transmission timing at which the control channel has not been correctly received by the receiver is identified based on the preceding system frame number.