Mobile station used as a repeater station when communicating with a base station

• US 7,092,434 B2
• Filed: 06/25/2002
• Issued: 08/15/2006
• Est. Priority Date: 06/25/2001
• Status: Expired due to Fees

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Futakata, Toshiyuki, Moon, Sung Uk
• Primary Examiner(s): Patel, Jay K.
• Assistant Examiner(s): DSOUZA, JOSEPH FRANCIS A
• Application Number:
  US10/178,544
• Publication Number:
  US 20020197969A1
• Time in Patent Office: 1,512 Days
• Field of Search: 375/211, 455/442, 455/445, 370/315
• US Class Current: 375/211
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

When a mobile station communicates with a base station by way of one or a plurality of other mobile stations, the mobile station acting as a relay station determines whether the data demodulated after being received is reception data for the mobile station or transfer data to be transmitted to the other mobile station or the base station, decides a modulation mode suitable for transmitting sum data of the transfer data and transmission data if the transmission data is generated in the mobile station, and transmits the sum data while modulating the sum data according to the modulation mode decided. The base station demodulates a reception signal relayed by the mobile stations according to the modulation mode of the mobile station having directly communicated with the base station, and identifies each user data multiplexed.

Claims

1. A mobile station used as a repeater station when a mobile station communicates with a base station by way of at least one other mobile station in an Opportunity Driven Multiple Access (ODMA) scheme, said mobile station comprising:

determining means for determining whether data demodulated after being received is reception data for said mobile station or transfer data to be transferred to the other mobile station or the base station;

adding means for adding transmission data to said transfer data and outputting thus obtained sum data if said transmission data is generated in the mobile station, and outputting said transfer data alone if there is no transmission data;

deciding means for deciding a modulation mode suitable for transmitting data outputted from said adding means according to an amount of said data; and

modulating means for modulating said data outputted from said adding means according to said modulation mode decided by said deciding means.

2. A mobile station according to claim 1, wherein said deciding means employs a modulation mode having a greater number of modulation values as said data outputted from said adding means has a greater amount.

3. A base station comprising:

demodulating means for demodulating a reception signal relayed by the mobile station according to claim 1 according to a modulation mode of the mobile station having directly communicated with said base station; and

discriminating means for identifying each data item multiplexed and included in said data demodulated by said demodulating means.

4. A base station according to claim 3, further comprising multiplexing means for multiplexing data corresponding to a plurality of mobile stations, said data multiplexed by said multiplexing means being transmitted to one of said mobile stations.

5. A mobile communication system employing an Opportunity Driven Multiple Access (ODMA) scheme allowing a mobile station to communicate with a base station by way of at least one other mobile station, said mobile communication system comprising:

a mobile station for determining whether data demodulated after being received is reception data for said mobile station or transfer data to be transferred to the other mobile station or the base station, deciding a modulation mode suitable for transmitting sum data of transmission data and said transfer data according to an amount of said sum data if said transmission data is generated in said mobile station, and transmitting said sum data while modulating said sum data according to said modulation mode decided; and

a base station for demodulating a reception signal relayed in said ODMA scheme according to a modulation mode of the mobile station having directly communicated with said base station, identifying each data item multiplexed and included in thus demodulated data, multiplexing data to be transmitted to a plurality of mobile stations, and transmitting thus multiplexed data to said mobile station.

6. A mobile communication method for allowing a mobile station to communicate with a base station by way of at least one other mobile station in an Opportunity Driven Multiple Access (ODMA) scheme, said method comprising:

a determining step of determining whether data demodulated after being received is reception data for said mobile station or transfer data to be transferred to the other mobile station or the base station;

an adding step of adding transmission data to said transfer data and outputting thus obtained sum data if said transmission data is generated in said mobile station, and outputting said transfer data alone if there is no transmission data;

a deciding step of deciding a modulation mode suitable for transmitting data obtained by said adding step according to an amount of said data; and

a modulating step of modulating said data obtained by said adding step according to said modulation mode decided by said deciding step.

7. A mobile communication method according to claim 6, wherein said deciding step employs a modulation mode having a greater number of modulation values as said data outputted in said adding step has a greater amount.

8. A mobile communication method according to claim 6, further comprising in the base station:

a demodulating step of demodulating a reception signal relayed by said mobile station according to a modulation mode of the mobile station having directly communicated with said base station; and

discriminating step of identifying each data item multiplexed and included in said data demodulated by said demodulating step.

9. A mobile communication method according to claim 8, further comprising in said base station, a multiplexing step of multiplexing data corresponding to a plurality of mobile stations, said data multiplexed by said multiplexing step being transmitted to one of said mobile stations.

10. A mobile communication program for allowing a mobile station to communicate with a base station by way of at least one other mobile station in an Opportunity Driven Multiple Access (ODMA) scheme, said program causing a computer to execute:

a determining step of determining whether data demodulated after being received is reception data for said mobile station or transfer data to be transferred to the other mobile station or the base station;

an adding step of adding transmission data to said transfer data and outputting thus obtained sum data if said transmission data is generated in said station, and outputting said transfer data alone if there is no transmission data;

a deciding step of deciding a modulation mode so as to attain a greater number of modulation values as the amount of data obtained by said adding step is greater; and

a modulating step of modulating said data obtained by said adding step according to said modulation mode decided by said deciding step.

11. A mobile communication program according to claim 10, further causing said computer to execute:

a demodulating step of demodulating a reception signal relayed by said mobile station according to a modulation mode of the mobile station having directly communicated with said base station; and

discriminating step of identifying each data item multiplexed and included in said data demodulated by said demodulating step.