COMMUNICATION TERMINAL APPARATUS, COMMUNICATION SYSTEM, COMMUNICATION METHOD, AND PROGRAM

• US 20080125049A1
• Filed: 11/23/2007
• Published: 05/29/2008
• Est. Priority Date: 11/24/2006
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: SUZUKI, Koichi, ICHIMASA, Takashi
• Granted Patent: US 7,885,605 B2
• Time in Patent Office: Days
• US Class Current: 455/63.1
• CPC Class Codes: H04L 1/0053 specially adapted for power saving
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal
• CPC Class Codes: H04L 1/1845 Combining techniques, e.g. code combining
• CPC Class Codes: H04L 1/20 using signal quality detector

Abstract

A communication terminal apparatus, communication system, communication method, and program are provided that enable a decoding section of a mobile communication apparatus to be controlled and operated only when necessary even when receive data retransmission occurs. A radio communication apparatus 100 is equipped with a radio antenna 101, a demodulation section 102 that performs demodulation of receive data, a data combining section 103 that combines the demodulated data with past data, a decoding section 104 that decodes the combined data, an error correction section 105 that performs error correction processing using the decoded data, an error determination section 106 that determines a data error using the data on which error correction processing has been performed, a transmitting section 107, a retransmission determination section 108 that determines data reliability and the number of retransmission requests based on the communication state of receive data, and a control section 109 that controls each of the above sections, and control section 109 stops the operation of decoding section 104 and subsequent sections until data reliability determined by retransmission determination section 108 exceeds a predetermined threshold value.

Claims

1. A communication terminal apparatus comprising:

a demodulation section that performs demodulation of receive data;

a data combining section that combines said demodulated data with past data;

a decoding section that decodes said combined data;

an error correction section that performs error correction processing using said decoded data;

an error determination section that determines a data error using data on which said error correction processing has been performed;

a data reliability determination section that determines data reliability based on a communication state of said receive data; and

a control section that stops operation of said decoding section until said data reliability exceeds a predetermined threshold value.

2. The communication terminal apparatus according to claim 1, wherein said control section stops operation of said decoding section, said error correction section, and said error determination section until said data reliability exceeds a predetermined threshold value.

3. The communication terminal apparatus according to claim 1, wherein said control section, when said data reliability exceeds a predetermined threshold value, enables operation of said decoding section, said error correction section, and said error determination section, and enables data transfer from said data combining section to said decoding section.

4. The communication terminal apparatus according to claim 1, wherein said control section issues a retransmission request at predetermined timing until said data reliability exceeds a predetermined threshold value.

5. The communication terminal apparatus according to claim 1, wherein said control section sets a number of retransmission requests based on a communication state of said receive data.

6. The communication terminal apparatus according to claim 1, wherein said data reliability determination section has beforehand a data reliability of each packet corresponding to a plurality of communication states, adds data reliabilities of said each packet at a timing related to said packet arrival, and determines that data reliability after addition exceeds a predetermined threshold value.

7. The communication terminal apparatus according to claim 1, further comprising:

a field strength map that stores a field strength rank at a specific position within a radio communication coverage area of a base station;

a number-of-retransmissions record table showing correspondence between said field strength rank and a retransmission request record value; and

a position information measuring section that measures position information,

wherein said control section references said field strength map based on said measured position information and finds said field strength rank, and references said number-of-retransmissions record table based on that field strength rank and sets a number of retransmission requests.

8. The communication terminal apparatus according to claim 7, further comprising a mode setting section that sets a mode that uses said position information,

wherein said control section, when said mode using position information has been set, references said field strength map based on said measured position information and finds said field strength rank, and references said number-of-retransmissions record table based on that field strength rank and sets a number of retransmission requests.

9. The communication terminal apparatus according to claim 7, further comprising a field strength map creation section that creates or updates said field strength map based on a communication state of said receive data at said measured specific position.

10. A communication system equipped with a base station and a plurality of communication terminal apparatuses present within a radio communication coverage area of said base station, wherein said communication terminal apparatuses comprise:

a demodulation section that performs demodulation of receive data;

a data combining section that combines said demodulated data with past data;

a decoding section that decodes said combined data;

an error correction section that performs error correction processing using said decoded data;

an error determination section that determines a data error using data on which said error correction processing has been performed;

a data reliability determination section that determines data reliability based on a communication state of said receive data; and

a control section that stops operation of said decoding section, or operation of said decoding section, said error correction section, and said error determination section, until said data reliability exceeds a predetermined threshold value.

11. The communication system according to claim 10, wherein said control section issues a retransmission request to said base station at predetermined timing until said data reliability exceeds a predetermined threshold value.

12. The communication system according to claim 10, wherein:

said communication terminal apparatuses further comprise;

a field strength map that stores a field strength rank at a specific position within a radio communication coverage area of said base station;

a number-of-retransmissions record table showing correspondence between said field strength rank and a retransmission request record value;

a position information measuring section that measures position information of the apparatus itself; and

a mode setting section that sets a mode that uses said position information in accordance with a directive from said base station, and

said control section, when said mode using position information has been set, references said field strength map based on said measured position information and finds said field strength rank, and references said number-of-retransmissions record table based on that field strength rank and sets a number of retransmission requests.

13. The communication system according to claim 10, wherein said base station further comprises a field strength map creation section that creates or updates said field strength map based on a communication state of said receive data at said specific position measured by said plurality of communication terminal apparatuses.

14. A communication method that performs radio communication via a base station, said communication method comprising:

a step of performing demodulation of receive data;

a step of combining said demodulated data with past data;

a decoding step of decoding said combined data;

a step of performing error correction processing using said decoded data;

a step of determining a data error using data on which said error correction processing has been performed;

a step of determining data reliability based on a communication state of said receive data; and

a step of issuing a retransmission request to said base station at predetermined timing and stopping operation of said decoding step onward until said data reliability exceeds a predetermined threshold value.

15. A program that causes a computer to execute a communication method that performs radio communication via a base station, said communication method comprising:

a step of performing demodulation of receive data;

a step of combining said demodulated data with past data;

a decoding step of decoding said combined data;

a step of performing error correction processing using said decoded data;

a step of determining a data error using data on which said error correction processing has been performed;

a step of determining data reliability based on a communication state of said receive data; and

a step of issuing a retransmission request to said base station at predetermined timing and stopping operation of said decoding step onward until said data reliability exceeds a predetermined threshold value.