WIRELESS COMMUNICATION SYSTEM, BASE STATION DEVICE, AND TERMINAL DEVICE

• US 20130336418A1
• Filed: 03/02/2012
• Published: 12/19/2013
• Est. Priority Date: 03/04/2011
• 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: Tomeba, Hiromichi, Onodera, Takashi, Nakano, Hiroshi, Ruiz Delgado, Alvaro, To, Shimpei
• Granted Patent: US 9,130,629 B2
• Time in Patent Office: Days
• US Class Current: 375/267
• CPC Class Codes: H04B 7/0452 Multi-user MIMO systems
• CPC Class Codes: H04B 7/0465 taking power constraints at power amplifier or emission constraints, e.g. constant modulus, into account
• CPC Class Codes: H04B 7/0482 Adaptive codebooks
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04B 7/0697 using spatial multiplexing
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes

Abstract

A terminal device notifies a base station device about control information associated with a receive quality of the terminal device. The base station device performs data modulation on a plurality of pieces of transmit data for the terminal device, by using a plurality of different data modulation schemes one by one, based on the control information, and spatially multiplexes the plurality of pieces of transmit data after the data modulation over a single wireless resource and transmits a spatially multiplexed signal. The terminal device receives the signal with the plurality of pieces of transmit data spatially multiplexed, and detects desirable transmit data from the receive signal, based on a first channel matrix which represents channel state information between the base station device and the terminal device and a second channel matrix in which the first channel matrix is multiplied by a transform matrix. Accordingly, an adaptive modulation technology is applied even to MIMO spatial multiplexing transmission using a LR technology, and hence a wireless communication system and so forth that can contribute to improvement in frequency utilization efficiency can be provided.

Claims

1-17. -17. (canceled)

18. A base station device that includes a plurality of antennas and makes communication with a plurality of terminal devices each having at least one antenna,

wherein the base station device

is notified from the terminal devices about first control information associated with receive qualities of the terminal devices and second control information associated with first channel state information between the base station device and the terminal devices,

is able to use a plurality of different data modulation schemes,

performs data modulation on a plurality of pieces of transmit data for the plurality of terminal devices, by using the plurality of different data modulation schemes one by one, based on the first control information,

acquires a third channel matrix which represents channel state information between the base station device and the plurality of terminal devices, based on the first control information,

performs precoding on the plurality of pieces of transmit data after the data modulation, based on the third channel matrix and a fourth channel matrix in which the third channel matrix is multiplied by a transform matrix, the transform matrix being a transform matrix that transforms the third channel matrix into a matrix with high orthogonality, and

spatially multiplexes the plurality of pieces of transmit data after the precoding over a single wireless resource and transmits a spatially multiplexed signal.

19. The base station device according to claim 18,

wherein the plurality of different data modulation schemes are able to realize respective different frequency utilization efficiencies, and the plurality of different data modulation schemes are associated with the respective different frequency utilization efficiencies, and

wherein one of the plurality of different data modulation schemes, the one which is able to realize a maximum frequency utilization efficiency, serves as a first data modulation scheme.

20. The base station device according to claim 19, wherein a signal candidate point of each of the data modulation schemes is extracted from a signal candidate point of the first data modulation scheme.

21. The base station device according to claim 19, wherein an interval between signal candidate points of each of the data modulation schemes is associated to be an integral multiple of an interval between signal candidate points of the first data modulation scheme.

22. The base station device according to claim 21, wherein the signal candidate point of each of the data modulation schemes is associated to be extracted from a signal candidate point of a second data modulation scheme which is calculated from the first data modulation scheme and the transform matrix.

23. The base station device according to claim 19, wherein the precoding is nonlinear arithmetic processing including a modulo arithmetic.

24. A wireless communication system including a base station device having a plurality of antennas, and a plurality of terminal devices each having at least one antenna,

wherein the terminal devices

notify the base station device about first control information associated with receive qualities of the terminal devices and second control information associated with first channel state information between the base station device and the terminal devices,

wherein the base station device

is able to use a plurality of different data modulation schemes,

performs data modulation on a plurality of pieces of transmit data for the plurality of terminal devices, by using the plurality of different data modulation schemes one by one, based on the first control information,

acquires a third channel matrix which represents channel state information between the base station device and the plurality of terminal devices based on the first control information,

performs precoding on the plurality of pieces of transmit data after the data modulation, based on the third channel matrix and a fourth channel matrix in which the third channel matrix is multiplied by a transform matrix, the transform matrix being a transform matrix that transforms the third channel matrix into a matrix with high orthogonality, and

spatially multiplexes the plurality of pieces of transmit data after the precoding over a single wireless resource and transmits a spatially multiplexed signal, and

wherein the terminal devices

detect desirable data from the spatially multiplexed and transmitted signal.

25. A terminal device that includes a plurality of antennas and makes communication with a base station device having a plurality of antennas,

wherein the base station device

is able to use a plurality of different data modulation schemes, and

wherein the terminal device

receives a signal in which a plurality of pieces of transmit data after data modulation are spatially multiplexed, the data modulation being performed on the plurality of pieces of transmit data by using the plurality of different data modulation schemes one by one, based on control information associated with a receive quality of the terminal device and notified to the base station device, and

detects desirable transmit data from the receive signal, based on a first channel matrix which represents channel state information between the base station device and the terminal device and a second channel matrix in which the first channel matrix is multiplied by a transform matrix, the transform matrix being a transform matrix that transforms the first channel matrix into a matrix with high orthogonality.

26. The terminal device according to claim 25,

wherein the plurality of different data modulation schemes are able to realize respective different frequency utilization efficiencies, and the plurality of different data modulation schemes are associated with the respective different frequency utilization efficiencies, and

wherein one of the plurality of different data modulation schemes, the one which is able to realize a maximum frequency utilization efficiency, serves as a first data modulation scheme.

27. The terminal device according to claim 26, wherein a signal candidate point of each of the data modulation schemes is associated to be extracted from a signal candidate point of the first data modulation scheme.