Radio communication device and method of controlling transmission rate

• US 6,381,445 B1
• Filed: 08/28/2000
• Issued: 04/30/2002
• Est. Priority Date: 04/17/1998
• Status: Expired due to Term

• Current Assignee: INVT SPE LLC (SoftBank Group Corp.)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Hiramatsu, Katsuhiko, Kato, Osamu, Ue, Toyoki
• Primary Examiner(s): Hunter, Daniel
• Assistant Examiner(s): Gantt, Alan T.
• Application Number:
  US09/648,742
• Time in Patent Office: 610 Days
• Field of Search: 455/69, 455/67.1, 455/67.4, 455/63, 455/517, 455/522
• US Class Current: 455/69
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/22 Negotiating communication rate
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/265 taking into account the quality of service QoS
• CPC Class Codes: H04W 52/267 taking into account the information rate
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

The communication terminal apparatus measures reception quality and reports the measurement result to the base station apparatus, and the base station apparatus switches the transmission rate based on the reported result of the reception quality. In this way, the transmission rate is switched starting at the point in time at which the reception quality of the communication terminal apparatus deteriorates. Furthermore, the transmission rate is switched so that the amount of interference with others is within the allowable range according to the channel condition between the communication terminal apparatus and base station apparatus.

Claims

1. A transmission rate control apparatus comprising:

receiving means for receiving a retransmission request from a communication terminal; and

transmitting means for transmitting a received quality report request to the communication terminal at a timing at which the retransmission request is received; and

rate changing means for changing a transmission rate to said communication terminal based on the received quality measured at said communication terminal according to the received quality report request,

wherein said rate changing means decreases the transmission rate when the received quality at a side of said communication terminal deteriorates rapidly.

2. The transmission rate control apparatus according to claim 1, wherein, after said rate changing means decreases the transmission rate when the received quality at a side of said communication terminal deteriorates rapidly, said rate changing means changes the transmission rate to an original value when the received quality at the side of said communication terminal subsequently improves.

3. A base station apparatus provided with a transmission rate control apparatus comprising:

receiving means for receiving a retransmission request from a communication terminal;

transmitting means for transmitting a received quality report request to the communication terminal at a timing at which the retransmission request is received; and

rate changing means for changing a transmission rate to said communication terminal based on the received quality measured at said communication terminal according to the received quality report request,

wherein said rate changing means decreases the transmission rate when the received quality at a side of said communication terminal deteriorates rapidly.

4. The base station apparatus according to claim 3, wherein, after said rate changing means decreases the transmission rate when the received quality at a side of said communication terminal deteriorates rapidly, said rate changing means changes the transmission rate to an original value when the received quality at the side of said communication terminal subsequently improves.

5. A communication terminal apparatus comprising:

received quality measuring means for measuring a first received quality of a signal from a base station;

retransmission requesting means for requesting retransmission based on the first received quality;

monitoring means for monitoring a second received quality at said communication terminal apparatus;

receiving means for receiving a received quality report request transmitted from said base station at a timing at which the retransmission is received at said base station; and

transmitting means for transmitting the second received quality to said base station according to the received quality report request.

6. A transmission rate control method comprising:

a first step of receiving a retransmission request from a communication terminal; and

a transmitting step of transmitting a received quality report request to the communication terminal at a timing at which the retransmission request is received; and

a rate changing step of changing a transmission rate to said communication terminal based on the received quality measured at said communication terminal according to the received quality report request,

wherein the transmission rate is decreased when the received quality at a side of said communication terminal deteriorates rapidly.

7. The transmission rate control apparatus according to claim 6, wherein, after the transmission rate is decreased when the received quality at a side of said communication terminal deteriorates rapidly, the transmission rate is changed to an original value when the received quality at the side of said communication terminal subsequently improves.