Preamble trasmission method, mobile station, mobile communication system, preamble transmission program and computer data signal

• US 20040071194A1
• Filed: 07/08/2003
• Published: 04/15/2004
• Est. Priority Date: 11/08/2001
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Sawahashi, Mamoru, Atarashi, Hiroyuki, Suwa, Shingo
• Granted Patent: US 7,787,519 B2
• Time in Patent Office: Days
• US Class Current: 375/146
• CPC Class Codes: H04B 2201/70701 featuring pilot assisted reception
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 5/026 using code division
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal

Abstract

With the object of efficiently transmitting a variety of different information signals by utilizing the multi-carrier characteristics of Multi-carrier/DS-CDMA, the present invention is characterized in that, when, in an uplink transmission from a plurality of mobile stations to a base station, the mobile stations transmit a preamble to the base station before transmitting an information symbol sequence, the mobile stations individually select a carrier from among a plurality of carriers, and, up until receiving a preamble receipt confirmation signal from the base station with a prescribed maximum number of preamble transmissions serving as an upper limit number; the mobile stations repeatedly transmit a preamble by means of the selected carrier and vary the transmission power used for the transmissions of each carrier.

Claims

1. A preamble transmission method according to which, in an uplink transmission from each of a plurality of mobile stations to a base station, to which a direct sequence code division multiple access system that employs a plurality of carriers, is applied, the mobile stations transmit a preamble to the base station before transmitting an information symbol sequence, comprising:

a first carrier selection step in which the mobile stations individually select a carrier from among a plurality of carriers; and

a transmission control step in which, up until receiving a preamble receipt confirmation signal from the base station with a predetermined maximum number of preamble transmissions serving as an upper limit number, the mobile stations repeatedly transmit a preamble by means of the selected carrier and vary the transmission power used for the transmissions of each carrier.

2. The preamble transmission method according to claim 1, characterized in that, in the first carrier selection step, the mobile stations select a carrier on the basis of at least one of broadcast information that includes the total transmitted packet volume and the transmitted packet volume of each carrier which are reported by the base station, and the priority level and information volume of the transmitted information symbol sequence.

3. The preamble transmission method according to claim 1 or 2, characterized in that, in the transmission control step, the mobile stations vary the transmission power on the basis of at least one of broadcast information that includes the total transmitted packet volume and the transmitted packet volume by each carrier which are reported by the base station, the priority level and information volume of the transmitted information symbol sequence, and the number of carriers transmitting a preamble.

4. The preamble transmission method according to one of claims 1 to 3, characterized in that, in the transmission control step, the mobile stations allocate a spreading code pattern to the transmitted preamble on the basis of predetermined rules.

5. The preamble transmission method according to claim 4, characterized in that, in the transmission control step, the mobile stations vary the spreading code pattern allocated to the preamble on the basis of at least one of the priority level and the information volume of the transmitted information symbol sequence.

6. The preamble transmission method according to one of claims 1 to 5, further comprising:

a second carrier selection step in which, upon receiving a preamble receipt confirmation signal from the base station, the mobile stations select a carrier from among carriers by means of which a receipt-confirmed preamble has been transmitted; and

an information transmission step in which the mobile stations transmit an information symbol sequence by means of the selected carrier.

7. The preamble transmission method according to any one of claims 1 to 5, further comprising:

a third carrier selection step in which, upon receiving a preamble receipt confirmation signal from the base station, the mobile stations select a carrier from among carriers by means of which a receipt-confirmed preamble has been transmitted; and

a collision sensing signal transmission step in which the mobile stations transmit a preamble used for sensing a collision with another mobile station by means of the selected carrier.

8. A mobile station which, in an uplink transmission from this mobile station to a base station to which a direct sequence code division multiple access system that employs a plurality of carriers, is applied, transmits a preamble before transmitting an information symbol sequence, comprising:

carrier selection control means for selecting a carrier from among a plurality of carriers individually for each mobile station;

transmission control means for repeatedly transmitting a preamble by means of the selected carrier until a preamble receipt confirmation signal is received from the base station with a predetermined maximum number of preamble transmissions serving as an upper limit number; and

power control means for exercising control so as to vary the transmission power used for the transmissions of each carrier.

9. The mobile station according to claim 8, characterized in that the carrier selection control means selects a carrier on the basis of at least one of broadcast information that includes the total transmitted packet volume and the transmitted packet volume of each carrier which are reported by the base station, and the priority level and information volume of the transmitted information symbol sequence.

10. The mobile station according to claim 8 or 9, characterized in that the power control means exercises control so as to vary the transmission power on the basis of at least one of broadcast information that includes the total transmitted packet volume and the transmitted packet volume of each carrier which are reported by the base station, the priority level and information volume of the transmitted information symbol sequence, and the number of carriers transmitting a preamble.

11. The mobile station according to one of claims 8 to 10, characterized by further comprising:

pattern allocation control means for allocating a spreading code pattern to the transmitted preamble on the basis of predetermined rules.

12. The mobile station according to claim 11, characterized in that the pattern allocation control means varies the spreading code pattern allocated to the preamble on the basis of at least one of the priority level and the information volume of the transmitted information symbol sequence.

13. The mobile station according to one of claims 8 to 12, characterized in that, upon receiving a preamble receipt confirmation signal from the base station, the carrier selection control means selects a carrier from among carriers by means of which a receipt-confirmed preamble has been transmitted;

and

the transmission control means transmits an information symbol sequence by means of the selected carrier.

14. The mobile station according to one of claims 8 to 12, characterized in that, upon receiving a preamble receipt confirmation signal from the base station, the carrier selection control means selects a carrier from among carriers by means of which a receipt-confirmed preamble has been transmitted;

and

the transmission control means transmits a preamble used for sensing a collision with another mobile station by means of the selected carrier.

16. A preamble transmission program for causing a computer, which is housed in a mobile station that transmits a preamble before transmitting an information symbol sequence in an uplink transmission from this mobile station to a base station, to which a direct sequence code division multiple access system that employs a plurality of carriers, is applied, to function as each of the means according to one of claims 8 to 14.

17. A computer data signal embedded in a carrier wave and which serves to cause a computer, which is housed in a mobile station that transmits a preamble before transmitting an information symbol sequence in an uplink transmission from this mobile station to a base station, to which a direct sequence code division multiple access system that employs a plurality of carriers, is applied, to function as each of the means according to one of claims 8 to 14.

15. A mobile communications system which comprises a base station and a plurality of mobile stations, and according to which a direct sequence code division multiple access system that employs a plurality of carriers, is applied to an uplink transmission from the mobile stations to the base station,

characterized in that each of the mobile stations includes:

carrier selection control means for selecting a carrier from among a plurality of carriers individually for each mobile station;

transmission control means for repeatedly transmitting a preamble by means of the selected carrier until a preamble receipt confirmation signal is received from the base station with a prescribed maximum number of preamble transmissions serving as an upper limit number; and

power control means for exercising control so as to vary the transmission power used for the transmissions of each carrier.