Radio communication device and method of controlling transmission rate

• US 7,636,551 B2
• Filed: 09/19/2005
• Issued: 12/22/2009
• Est. Priority Date: 04/17/1998
• Status: Expired due to Fees

• Current Assignee: INVT SPE LLC (FIG LLC (d/b/a Fortress Investment Group LLC))
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Hiramatsu, Katsuhiko, Kato, Osamu, Ue, Toyoki
• Primary Examiner(s): Bost; Dwayne
• Assistant Examiner(s): Mehra; Inder P
• Application Number:
  US11/228,339
• Publication Number:
  US 20060019610A1
• Time in Patent Office: 1,555 Days
• Field of Search: 455/63.1, 455/67.11, 455/67.13, 455/67.14, 455/69, 455/92, 455/522, 455/450, 370/320, 370/335, 370/342, 370/391, 370/441
• US Class Current: 455/63.1
• 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 radio communication apparatus of a radio communication system wherein communication signals are transmitted between the radio communication apparatus and at least one communication terminal, said apparatus comprising:

a measurement result obtainer that obtains a measurement result of the reception quality of the communication signals at the communication terminal;

a transmission section that transmits a transmission signal in a communication channel from the radio communication apparatus to the communication terminal with a predetermined transmission rate;

a comparison section that compares the reception quality measurement result with a respective threshold to determine the communication channel condition; and

a transmission rate switching controller that switches the transmission rate according to the result of comparing the reception quality measurement result with the respective threshold to allow a variation of the transmission rate, wherein;

the radio communication system is a CDMA communication system and the threshold is set depending on the number of multiplexing codes.

2. The radio communication apparatus according to claim 1, wherein the transmission rate switching controller selects a transmission rate that meets a predetermined reception quality and allows the fastest transmission.

3. The radio communication apparatus according to claim 1, wherein the reception quality measurement result is communicated from the communication terminal.

4. The radio communication apparatus according to claim 3, wherein the reception quality is measured periodically or on demand from the communication apparatus.

5. The radio communication apparatus according to claim 1, further comprising a reception quality estimation section that estimates the reception quality measurement result on the basis of transmission power control information from the communication terminal.

6. A method in a radio communication system wherein communication signals are transmitted between a radio communication apparatus and a communication terminal, said method comprising:

obtaining a measurement result of the reception quality of the communication signals at the communication terminal;

transmitting a transmission signal in a communication channel from the radio communication apparatus to the communication terminal with a predetermined transmission rate;

comparing the reception quality measurement result with a respective threshold to determine the communication channel condition; and

switching the transmission rate according to the comparing result of the reception quality measurement with the respective threshold to allow a variation of the transmission rate, wherein;

the radio communication system is a CDMA system and said method further comprises setting the threshold dependent on the number of multiplexing codes.

7. The method according to claim 6, further comprising selecting a transmission rate that meets a predetermined reception quality and allows the fastest transmission.

8. The method according to claim 6, further comprising communicating the reception quality measurement result from the communication terminal.

9. The method according to claim 8, further comprising measuring the reception quality periodically or on demand from the radio communication apparatus.

10. The method according to claim 6, further comprising estimating the reception quality measurement result on the basis of transmission power control information from the communication terminal.

11. A communication system comprising:

a communication terminal that comprises;

a transmission section that transmits a measurement result of the reception quality of received communication signals;

a radio communication apparatus that comprises;

a measurement result obtainer that obtains the measurement result,

a transmission section that transmits a transmission signal in a communication channel to the communication terminal with a predetermined transmission rate,

a comparison section that compares the reception quality measurement result with a respective threshold to determine the communication channel condition, and

a transmission rate switching controller that switches the transmission rate according to the result of comparing the reception quality measurement result with the respective threshold to allow a variation of the transmission rate, wherein;

the radio communication system is a CDMA communication system and the threshold is set depending on the number of multiplexing codes.

12. The radio communication system according to claim 11, wherein the transmission rate switching controller selects a transmission rate that meets a predetermined reception quality and allows the fastest transmission.

13. The radio communication system according to claim 11, wherein the reception quality is measured periodically or on demand from the radio communication apparatus.

14. The radio communication system according to claim 11, said radio communication apparatus further comprising a reception quality estimation section that estimates the reception quality measurement result on the basis of transmission power control information from the communication terminal.