BASE STATION DEVICE, WIRELESS COMMUNICATION SYSTEM, WIRELESS COMMUNICATION METHOD, AND INTEGRATED CIRCUIT

• US 20150333808A1
• Filed: 11/01/2013
• Published: 11/19/2015
• Est. Priority Date: 12/07/2012
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: ONODERA, Takashi, TOMEBA, Hiromichi, RUIZ DELGADO, Alvaro, KUBOTA, Minoru
• Granted Patent: US 9,641,232 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 7/024 Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04W 16/10 Dynamic resource partitioning
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 72/541 using the level of interference

Abstract

A base station device according to the present invention receives wireless frames transmitted by terminal devices in nearby cells, estimates the state of the propagation channels between the terminal devices in the nearby cells and itself, based on the received signals thereof, and performs precoding on transmission data addressed to terminal devices in its own cell, based on the estimation results of the propagation channel state, and transmits.

Claims

1-17. -17. (canceled)

18. A base station device comprising:

a wireless receiver configured to receive first wireless frames, which are wireless frames transmitted by a terminal device of a nearby cell;

a propagation channel estimator configured to estimate the state of a propagation channel between the terminal device of the nearby cell and the base station device, based on received signals of the first wireless frame;

a precoder configured to perform precoding on transmission data addressed to a terminal device in an own cell, based on the estimation results of the state of the propagation channel; and

a wireless transmitter configured to transmit the precoded transmission data.

19. The base station device according to claim 18, further comprising:

a terminal ID acquisition unit configured to acquire, from the first wireless frame, a terminal ID to identify the terminal device of the nearby cell; and

a propagation channel estimation results storage unit configured to store the estimation results of the state of the propagation channel,

wherein the propagation channel estimation results storage unit is configured to store the estimation results of the state of the propagation channel in a manner correlated with the acquired terminal ID, and

the precoder is configured to perform precoding on transmission data addressed to a terminal device of the own cell, based on at least one estimation result of the state of the propagation channel selected from the propagation channel estimation results storage unit.

20. The base station device according to claim 19,

wherein the wireless receiver is further configured to receive a second wireless frame, which is a wireless frame transmitted by a base station device of a nearby cell, and

the terminal ID acquisition unit is configured to acquire a terminal ID identifying the terminal device of the nearby cell, from at least one of the first wireless frame and the second wireless frame.

21. The base station device according to claim 19,

wherein the precoder is configured to select at least one of the estimation result of the state of the propagation channel, in newest order, from the propagation channel estimation results storage unit.

22. The base station device according to claim 19,

wherein the propagation channel estimator is further configured to estimate reception quality of the first wireless frame,

the propagation channel estimation results storage unit is configured to store the estimation results of the state of the propagation channel and the estimation results of the reception quality, in a manner correlated with the acquired terminal ID, and

the precoder is configured to select at least one of the estimation result of the state of the propagation channel, from the propagation channel estimation results storage unit, based on the estimation results of the reception quality relating to at least one terminal device of the nearby cell, stored in the propagation channel estimation results storage unit.

23. The base station device according to claim 22,

wherein the precoder is configured to select at least one of the estimation result of the state of the propagation channel, from the propagation channel estimation results storage unit, in highest order of estimation results of the reception quality relating to at least one terminal device of the nearby cell, stored in the propagation channel estimation results storage unit.

24. The base station device according to claim 19,

wherein the precoder is configured to select estimation results of the state of propagation channels as to at least one of the terminal device in the nearby cell, from the propagation channel estimation results storage unit, the upper limit of the number thereof being the same as the number of antenna degrees of freedom of the base station device.

25. The base station device according to claim 19,

wherein the precoder is configured to perform precoding on transmission data addressed to a terminal device of the own cell so that a null is directed toward a corresponding terminal device of the nearby cell, based on the at least one estimation result of the state of the propagation channel selected from the propagation channel estimation results storage unit.

26. The base station device according to claim 19, further comprising:

a propagation channel information storage unit configured to store propagation channel information based on the state of the propagation channel between the base station device and a terminal device of the own cell, notified from the terminal device of the own cell,

wherein the wireless receiver is further configured to receive a third wireless frame, which is a wireless frame including the propagation channel information notified from the terminal device of the own cell, and

the precoder is configured to perform precoding on transmission data addressed to at least one terminal device of the own cell, based on propagation channel information notified from the at least one terminal device of the own cell stored in the propagation channel information storage unit, and on the estimation results of the state of the propagation channels as to the at least one terminal device of the nearby cell selected from the propagation channel estimation results storage unit.

27. The base station device according to claim 26,

wherein the precoder is configured to select estimation results of the state of propagation channels as to at least one of the terminal device in the nearby cell, from the propagation channel estimation results storage unit, the upper limit of the number thereof being the same as an excess number of antenna degrees of freedoms of the base station device, obtained by subtracting the antenna degrees of freedom necessary to transmit the transmission data addressed to the at least one terminal device of the own cell.

28. The base station device according to claim 26,

wherein the precoder is configured

to suppress inter-user interference at the time of spatially multiplexing and simultaneously transmitting transmission data addressed to a plurality of terminal devices of the own cell, based on propagation channel information notified from the plurality of terminal devices of the own cell, stored in the propagation channel information storage unit, and also

to perform precoding on the transmission data addressed to the plurality of terminal devices of the own cell so that a null is directed toward a corresponding terminal device of the nearby cell, based on the at least one estimation result of the state of the propagation channel selected from the propagation channel estimation results storage unit.

29. A wireless communication method of a base station device configured to perform communication with a terminal device,

the communication method comprising

a step of receiving a wireless frame transmitted by a terminal device of a nearby cell,

a step of estimating the state of a propagation channel between the terminal device of the nearby cell and the base station device, based on a received signal of the wireless frame,

a step of performing precoding on transmission data addressed to a terminal device of the own cell, so that a null is directed toward a corresponding terminal device of the nearby cell, based on the estimation results of the state of the propagation channel, and

a step of transmitting the precoded transmission data.

30. A wireless communication method of a base station device configured to perform communication with a terminal device,

the communication method comprising

a step of receiving a wireless frame transmitted by a terminal device of a nearby cell,

a step of estimating a state of a propagation channel between the terminal device of the nearby cell and the base station device, based on a received signal of the wireless frame,

a step of receiving propagation channel information based on a state of a propagation channel between the base station device and the terminal device, notified from the terminal device of the own cell,

a step of suppressing inter-user interference at the time of spatially multiplexing and simultaneously transmitting transmission data addressed to at least one terminal device of the own cell, based on propagation channel information notified from the at least one terminal device of the own cell and the estimation results of the state of the propagation channel, and also performing precoding on transmission data addressed to the at least one terminal device of the own cell so that a null is directed toward a terminal device of the nearby cell corresponding to estimation results of the state of the propagation channel, and

a step of transmitting the precoded transmission data.