Packet communications taking into account channel quality and buffered data amount

• US 20040184417A1
• Filed: 12/17/2003
• Published: 09/23/2004
• Est. Priority Date: 12/17/2002
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Kayama, Hidetoshi, Chen, Lan, Umeda, Narumi
• Granted Patent: US 7,821,982 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0007 by modifying the frame length
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0017 where the mode-switching is based on Quality of Service requirement
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/20 using signal quality detector

Abstract

Base station (100) includes a channel quality detecting unit (120) that detects channel quality between the base station and a mobile station (200), a buffered data amount monitoring unit (130), and a modulation and coding set determination unit (150). The modulation and coding set determination unit determines a modulation and coding set, as a downlink modulation scheme for packet communications, such that a prescribed communication condition corresponding to the channel quality is satisfied, and that padding added to the data buffered in a transmission buffer (140) for subsequent transmission to the mobile station becomes the minimum.

Claims

1. A packet communications method for carrying out packet communications between a base station and a mobile station located in an area controlled by the base station, the method comprising:

detecting a channel quality between the base station and the mobile station;

detecting the amount of data buffered in a transmission buffer of a sender; and

determining a modulation scheme to be used in the packet communications based on the channel quality and the buffered data amount.

2. The packet communications method according to claim 1, wherein the modulation scheme is determined such that a prescribed communication condition is satisfied, and that padding, which is added to the data buffered in the transmission buffer of the sender when the buffered data amount is less than a transmission unit size, becomes the minimum, based on the channel quality and the buffered data amount.

3. A base station that carries out packet communications with a mobile station located in an area controlled by the base station, the base station comprising:

a channel quality detecting unit that detects a channel quality between the base station and the mobile station;

a buffered data monitoring unit that monitors the amount of data buffered in a transmission buffer of the base station; and

a modulation scheme determination unit that determines a modulation scheme for the packet communications based on the channel quality and the buffered data amount in the transmission buffer.

4. The base station according to claim 3, wherein the modulation scheme determination unit determines the modulation scheme that satisfies a prescribed communication condition, and that makes padding, which is added to the data buffered in the transmission buffer when the buffered data amount is less than a transmission unit size, become the minimum, based on the channel quality and the buffered data amount.

5. A mobile station that carries out packet communications with a base station, comprising:

a channel quality detecting unit that detects a channel quality between the base station and the mobile station;

a buffered data monitoring unit that monitors the amount of data buffered in a transmission buffer of the mobile station; and

a modulation scheme determination unit that determines a modulation scheme for the packet communications based on the channel quality and the buffered data amount in the transmission buffer.

6. The mobile station according to claim 5, wherein the modulation scheme determination unit determines the modulation scheme that satisfies a prescribed communication condition, and that makes padding, which is added to the data buffered in the transmission buffer when the buffered data amount is less than a transmission unit size, become the minimum, based on the channel quality and the buffered data amount.

7. A packet communication program used in packet communications between a base station and a mobile station located in an area controlled by the base station and installed in one of the base station and the mobile station that becomes a sender, the program comprising procedures of:

causing the sender to detect a channel quality between the base station and the mobile station;

causing the sender to detect the amount of data buffered in a transmission buffer of the sender; and

causing the sender to determines a modulation scheme for the packet communications based on the channel quality and the data amount in the transmission buffer of the sender.