MOBILE USER TERMINAL, MOBILE COMMUNICATION SYSTEM, BASE STATION, AND COMMUNICATION METHOD

• US 20130016683A1
• Filed: 09/20/2012
• Published: 01/17/2013
• Est. Priority Date: 09/20/2006
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Yano, Tetsuya, Obuchi, Kazuhisa, Miyazaki, Shunji, Nakagawa, Takao
• Granted Patent: US 9,088,392 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04B 17/24 with feedback of measurements to the transmitter
• CPC Class Codes: H04B 17/309 Measuring or estimating channel quality parameters
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0027 Scheduling of signalling, e.g. occurrence thereof
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A mobile user terminal, which transmits downlink channel quality information indicating downlink channel quality and an uplink pilot signal to a base station, whereby a carrier frequency used for transmitting the downlink quality information and a carrier frequency used for transmitting the uplink pilot signal are selectable respectively from among a plurality of carrier frequencies assigned to the mobile user terminal; the mobile user terminal includes a radio transmitter, which transmits the downlink quality information and the uplink pilot signal in an intermittent fashion to the base station; and the radio transmitter transmits the downlink quality information and the uplink pilot signal by using a same carrier frequency among the plurality of carrier frequencies or by using adjacent carrier frequencies among the plurality of carrier frequencies, in a period corresponding to a state of intermittent communicate.

Claims

1. A mobile user terminal, which transmits downlink channel quality information indicating downlink channel quality and an uplink pilot signal to a base station, wherein:

a carrier frequency used for transmitting the downlink quality information and a carrier frequency used for transmitting the uplink pilot signal are selectable respectively from among a plurality of carrier frequencies assigned to the mobile user terminal;

the mobile user terminal comprises a radio transmitter, which transmits the downlink quality information and the uplink pilot signal in an intermittent fashion to the base station; and

the radio transmitter transmits the downlink quality information and the uplink pilot signal by using a same carrier frequency among the plurality of carrier frequencies or by using adjacent carrier frequencies among the plurality of carrier frequencies, in a period corresponding to a state of intermittent communicate.

2. A mobile communication system in which downlink channel quality information indicating downlink channel quality and an uplink pilot signal are transmitted to a base station, wherein:

a carrier frequency used for transmitting the downlink quality information and a carrier frequency used for transmitting the uplink pilot signal are selectable respectively from among a plurality of carrier frequencies assigned to a mobile user terminal;

the mobile user terminal comprises a radio transmitter, which transmits the downlink quality information and the uplink pilot signal in an intermittent fashion to the base station; and

the radio transmitter transmits the downlink quality information and the uplink pilot signal by using a same carrier frequency among the plurality of carrier frequencies or by using adjacent carrier frequencies among the plurality of carrier frequencies, in a period corresponding to a state of intermittent communicate.

3. The mobile communication system as claimed in claim 2,

wherein the base station comprises a channel estimator which performs channel estimation for a channel used for transmission of the downlink quality information, by using the uplink pilot signal received from the mobile communication terminal as a reference channel.

4. A base station used in the mobile communication system as claimed in claim 2, the base station comprising a channel estimator which performs channel estimation for a channel used for transmission of the downlink quality information, by using the uplink pilot signal received from the mobile communication terminal as a reference channel.

5. A method for communication in which downlink channel quality information indicating downlink channel quality and an uplink pilot signal are transmitted to a base station, wherein:

a carrier frequency used for transmitting the downlink quality information and a carrier frequency used for transmitting the uplink pilot signal are selectable respectively from among a plurality of carrier frequencies assigned to a mobile user terminal; and

the method comprises transmitting the downlink quality information and the uplink pilot signal in an intermittent fashion to the base station, wherein

the downlink quality information and the uplink pilot signal are transmitted by using a same carrier frequency among the plurality of carrier frequencies or by using adjacent carrier frequencies among the plurality of carrier frequencies, in a period corresponding to a state of intermittent communicate.

6. The method as claimed in claim 5, comprising performing channel estimation for a channel used for transmission of the downlink quality information in the base station, by using the uplink pilot signal received from the mobile communication terminal as a reference channel.