JP5909060B2 - Wireless transmission device, wireless reception device, program, integrated circuit, and wireless communication system - Google Patents

Description

  The present invention relates to a wireless transmission device, a wireless reception device, and a wireless communication system that perform data transmission simultaneously from a wireless transmission device to a plurality of wireless reception devices using spatial multiplexing.

  MIMO (Multiple-Input Multiple-Output) transmission technology that uses multiple antennas for transmission and reception, spatially multiplexes multiple different data sequences (data streams) in the same frequency band and communicates simultaneously, It has been put to practical use in wireless LANs and cellular systems. Single user MIMO (Single User MIMO), which spatially multiplexes multiple different data sequences and transmits them to a single wireless receiver (terminal device), improves the performance of separating and detecting multiple data sequences in the wireless receiver In order to achieve this, there is a method of performing transmission after precoding a transmission signal in a wireless transmission device (base station device, access point). In a next-generation cellular system, wireless LAN, or the like, a system has been proposed in which the number of transmission antennas included in a wireless transmission device is significantly larger than the number of reception antennas included in a wireless reception device. In such a system, a multi-user MIMO (Multi-User MIMO) that multiplexes data sequences addressed to a plurality of radio receiving apparatuses (users) in order to further improve the system throughput by effectively using the transmitting antenna of the radio transmitting apparatus. MIMO) has been proposed.

  However, since signals received by other wireless receiving devices cannot be known among a plurality of wireless receiving devices that receive signals multiplexed in multi-user MIMO, between users occurring between streams directed to each user as they are Interference (Multi-User Interference: MUI) significantly degrades the characteristics. Here, if the wireless transmission device knows CSI (Channel State Information) that is channel state information from each transmission antenna of the wireless transmission device to each reception antenna of each wireless reception device, a large load is applied to the wireless reception device. Several methods have been proposed that can generate a transmission signal that can suppress MUI at the time of reception in a wireless reception device (Non-Patent Document 1).

For example, there is a method of performing transmission after precoding a transmission signal in a wireless transmission device so that reception can be performed in a state where MUI is suppressed at the time of reception in the wireless reception device. As an example, from the channel matrix H having the complex propagation path gain between each transmission antenna and each reception antenna of each wireless reception device obtained from CSI as its element, its inverse matrix H ⁻¹ (or pseudo inverse matrix H ^† = H ^H (HH ^H ) ⁻¹ : The superscript H represents Hermitian conjugate) is used as a weighting matrix (linear filter) W to weight the transmission signal (multiply the transmission signal by W = H ⁻¹ ). Weight matrix (linear filter) W = H ^H (HH ^H + αI) ⁻¹ (I is a unit matrix, α) obtained by Zero-forcing (ZF) precoding or Minimum Mean Square Error (MMSE) norm There is linear precoding (LP) that precodes a transmission signal by linear processing, such as MMSE precoding that weights the transmission signal with a normalization coefficient.

As another example, a signal point where transmission power is reduced in the signal space in order to suppress transmission power that is increased after interference subtraction is performed by subtracting the interference signal component obtained from CSI in advance. There is non-linear precoding (NLP) in which a transmission signal is precoded by non-linear processing for encoding a signal after interference subtraction. As one of the nonlinear precoding, Tomlinson-Harashima, which can suppress an increase in transmission power by performing a modulo operation on a signal in both a radio transmission apparatus and a radio reception apparatus. Precoding (Tomlinson-Harashima Precoding: THP) has been proposed (Non-Patent Document 2, Non-Patent Document 3, Non-Patent Document 4). At this time, the radio receiving apparatus on the receiving side also performs the modulo operation similar to the transmission on the received signal. Here modulo operation Mod _tau modulo width tau, when a complex vector representing the received signal in the signal or receiver after interference subtraction on the transmission side [nu, represented by the formula (1). J is an imaginary unit, floor (a) is the maximum integer not exceeding a, and Re (ν) and Im (ν) are the real part of the complex number ν (corresponding to the in-phase component of the signal) and the imaginary part ( Corresponding to the orthogonal component of the signal). Note that the non-linear processing here mainly means processing using discontinuous points in the output such as modulo arithmetic.

  Furthermore, considering the characteristic degradation called Modulo-Loss at low signal-to-noise power ratio (SNR) caused by modulo arithmetic in THP, the MUI is small and the transmission power suppression effect by modulo arithmetic is small. A method for performing non-linear precoding by THP by applying modulo arithmetic only to a terminal having a large MUI and a large transmission power suppression effect by modulo arithmetic, by performing the same processing as linear precoding without applying modulo arithmetic for the terminal Has been proposed (Non-Patent Document 6).

  On the other hand, as a method for identifying a plurality of radio reception devices that are destinations of a data sequence spatially multiplexed on a multiuser MIMO signal transmitted from a radio transmission device, a combination (group) of radio reception devices spatially multiplexed by multiuser MIMO The method of embedding a group ID (Group ID: GID) for identifying each group in the control information of the transmission frame at the time of multi-user MIMO transmission is the IEEE (The Institute of Electrical and Electronics) Engineers, Inc.) 801.11ac (Non-Patent Document 7). Here, each wireless reception device can belong to a plurality of groups. Note that the above combinations are groups in which a wireless transmission device (access point) determines a combination (group) of wireless reception devices spatially multiplexed by multiuser MIMO and identifies each group prior to multiuser MIMO transmission. An ID is added to notify each wireless reception device to which group it belongs. The group configuration is notified to the wireless reception device by the wireless transmission device.

Spencer et al., "An Introduction to the Multi-User MIMO Downlink", IEEE Communication Magazine, Vol. 42, Issue 10, p. 60-67, October 2004 Harashima et al., "Matched-Transmission Technique for Channels With Intersymbol Interference", IEEE Transaction on Communications, Vol.COM-20, No.4, p.774-780, August 1972 J. Liu et al., “Improved Tomlinson-Harashima Precoding for the Downlink of Multiple Antenna Multi-User Systems”, Proc. IEEE Wireless and Communications and Networking Conference, p.466-472, March 2005. M. Joham et al., “MMSE Approaches to Multiuser Spatio-Temporal Tomlinson-Harashima Precoding”, Proc. 5th Int. ITG Conf. On Source and Channel Coding, p.387-394, January 2004 P.W.Wolniansky et al., `` V-BLAST: an architecture for realizing very high data rates over the rich-scattering wireless channel '', Proc.ISSSE-98, p.295-300, September 1998 Nakano et al., “Proposal for Downlink MU-MIMO THP to Adaptively Control Transmission Methods”, IEICE Technical Report, RCS2009-293, March 2010 `` IEEE P802.11 Wireless LANs Specification Framework for TGac '', IEEE 802.11-09 / 0992r21, January 2011 Kazuki Takeda et al., “Single-Carrier HARQ Using Joint THP and FDE”, Proc. 2007 IEEE 66th Vehicular Technology Conference (VTC-2007 Fall), p.1188-1192, September 2007

  Unlike a case of linear precoding, a radio reception apparatus that receives a signal that has been subjected to interference suppression by nonlinear precoding needs to perform the same modulo operation on the received signal as the transmission side. For this reason, in a wireless communication system, when a wireless transmission device supports both linear precoding and nonlinear precoding and a wireless reception device supports both linear precoding and nonlinear precoding, it is further non-patented. When two types of interference suppression methods are used in combination, such as when the wireless transmission device performs interference suppression by simultaneously combining linear precoding and nonlinear precoding as in Document 6, the wireless reception device It is necessary to switch whether to perform modulo calculation according to the interference suppression method. For this reason, the radio transmission apparatus controls whether a signal received by the radio reception apparatus is linear precoding or non-linear precoding with respect to a reception apparatus that receives a signal transmitted with interference suppressed. There is a problem that the amount of control information increases because it is necessary to notify the information.

  The present invention has been made in view of such circumstances, and does not increase the amount of control information whether the multiuser MIMO signal transmitted from the wireless transmission device is linear precoding or non-linear precoding. It is an object of the present invention to provide a wireless transmission device, a wireless reception device, a program, an integrated circuit, and a wireless communication system that can notify the wireless reception device.

  (1) In order to achieve the above object, the present invention takes the following measures. That is, a wireless transmission device of the present invention is a wireless transmission device that includes a plurality of transmission antennas and transmits a spatially multiplexed signal to a plurality of wireless reception devices, and each of the wireless reception devices is grouped into at least one group. A group configuration unit that determines the precoding scheme for each group, a selection unit that selects one of the groups, and transmission data addressed to each wireless reception device that belongs to the selected group. On the other hand, a precoding unit that performs precoding with the precoding scheme determined for the selected group is provided.

  In this way, since transmission data addressed to each wireless reception device belonging to the selected group is precoded by the precoding scheme determined for the selected group, the wireless reception device It is possible to identify from the group what precoding scheme the transmitted spatial multiplexing signal has been precoded. As a result, it is possible to notify the wireless receiver of the precoding scheme without increasing the amount of control information.

  (2) In addition, the wireless transmission device of the present invention includes a group storage unit that stores the determined group, a configuration information generation unit that generates group configuration information for each group, and a group identification of the selected group An identification information generation unit that generates information, and transmits the group configuration information, the group identification information, and the precoded signal to each wireless reception device belonging to the selected group, To do.

  With this configuration, it is possible to notify the wireless receiver of the precoding scheme without increasing the amount of control information.

  (3) Further, in the wireless transmission device of the present invention, the precoding scheme is one of linear precoding and nonlinear precoding.

  With this configuration, both linear precoding and non-linear precoding can be handled, and both can be switched and used.

  (4) The wireless transmission device of the present invention is a wireless transmission device that includes a plurality of transmission antennas and transmits a spatially multiplexed signal to a plurality of wireless reception devices, and includes at least one of the wireless reception devices. Belonging to one group, a group configuration unit for determining a precoding scheme for each wireless reception device belonging to each group, a selection unit for selecting any one group from each group, and the selected group And a precoding unit that performs precoding on transmission data addressed to each wireless reception device to which the wireless reception device belongs by a precoding scheme determined for each wireless reception device.

  As described above, since transmission data addressed to each wireless reception device belonging to the selected group is precoded by the precoding scheme determined for each wireless reception device, the wireless reception device can It is possible to identify from the group what precoding scheme the transmitted spatial multiplexing signal has been precoded. As a result, it is possible to notify the wireless receiver of the precoding scheme without increasing the amount of control information. In addition, different precoding schemes can be mixed for each of a plurality of radio receiving apparatuses and used separately.

  (5) In addition, the wireless transmission device of the present invention includes a group storage unit that stores the determined group, a configuration information generation unit that generates group configuration information for each group, and a group identification of the selected group An identification information generation unit that generates information, and transmits the group configuration information, the group identification information, and the precoded signal to each wireless reception device belonging to the selected group, To do.

  With this configuration, it is possible to notify the wireless receiver of the precoding scheme without increasing the amount of control information.

  (6) Further, in the wireless transmission device of the present invention, the precoding scheme is one of linear precoding and nonlinear precoding.

  With this configuration, both linear precoding and non-linear precoding can be handled, and both can be switched and used.

  (7) According to another aspect of the present invention, there is provided a wireless reception device that receives a spatially multiplexed signal from a wireless transmission device having a plurality of transmission antennas, the transmission destination of the spatially multiplexed signal being A receiving unit that receives group configuration information and group identification information of a group to which the wireless receiving device belongs, and a determination unit that determines whether the own device belongs to the group based on the group configuration information and group identification information; A reception processing unit for performing a reception process corresponding to a precoding scheme determined for each group on a signal addressed to the own device when the own device belongs to the group as a result of the determination; To do.

  In this way, when the own apparatus belongs to the group, the reception processing corresponding to the precoding scheme determined for each group is performed, so in the radio reception apparatus, what is the spatial multiplexing signal transmitted from the radio transmission apparatus? It is possible to identify from the group whether the precoding has been performed with a proper precoding scheme. As a result, it is possible to notify the wireless receiver of the precoding scheme without increasing the amount of control information.

  (8) Further, in the radio reception apparatus of the present invention, the precoding scheme is either linear precoding or nonlinear precoding, and the reception processing unit is configured such that the precoding scheme is nonlinear precoding. Is characterized by performing a modulo operation on the received data symbols.

  With this configuration, both linear precoding and non-linear precoding can be handled, and both can be switched and used.

  (9) Further, the wireless reception device of the present invention is a wireless reception device that receives a spatially multiplexed signal from a wireless transmission device having a plurality of transmission antennas, and the transmission destination of the spatially multiplexed signal A receiving unit that receives group configuration information and group identification information of a group to which the wireless receiving device belongs, and a determination unit that determines whether the own device belongs to the group based on the group configuration information and group identification information; A reception processing unit for performing a reception process corresponding to a precoding scheme determined for the own device in the group on a signal addressed to the own device when the own device belongs to the group as a result of the determination; It is characterized by that.

  In this way, when the own device belongs to the group, a signal addressed to the own device is subjected to reception processing corresponding to the precoding scheme determined for the own device in the group, so that it is transmitted from the wireless transmission device. It is possible to identify from the group what precoding method the spatial multiplexing signal is precoded. As a result, it is possible to notify the wireless receiver of the precoding scheme without increasing the amount of control information.

  (10) In the radio reception apparatus of the present invention, the precoding scheme is either linear precoding or non-linear precoding, and the reception processing unit is configured such that the precoding scheme is non-linear precoding. Is characterized by performing a modulo operation on the received data symbols.

  With this configuration, both linear precoding and non-linear precoding can be handled, and both can be switched and used.

  (11) A program of the present invention is a program for controlling a wireless transmission device that includes a plurality of transmission antennas and that transmits a spatially multiplexed signal to a plurality of wireless reception devices. A process of belonging to at least one group, a process of determining a precoding scheme for each group, a process of selecting any one group from the groups, and addressed to each radio receiving apparatus belonging to the selected group A series of processes including precoding with the precoding scheme determined for the selected group and transmission data of the selected group.

  In this way, since transmission data addressed to each wireless reception device belonging to the selected group is precoded by the precoding scheme determined for the selected group, the wireless reception device It is possible to identify from the group what precoding scheme the transmitted spatial multiplexing signal has been precoded. As a result, it is possible to notify the wireless receiver of the precoding scheme without increasing the amount of control information.

  (12) A program according to the present invention is a program for controlling a wireless transmission device that includes a plurality of transmission antennas and that transmits a spatially multiplexed signal to a plurality of wireless reception devices. A process of belonging to at least one group, a process of determining a precoding scheme for each radio receiving apparatus belonging to each of the groups, a process of selecting any one group from the groups, and the selected group It is characterized in that a computer executes a series of processes of precoding the transmission data addressed to each wireless reception apparatus to which the transmission data is addressed by a precoding scheme determined for each wireless reception apparatus.

  As described above, since transmission data addressed to each wireless reception device belonging to the selected group is precoded by the precoding scheme determined for each wireless reception device, the wireless reception device can It is possible to identify from the group what precoding scheme the transmitted spatial multiplexing signal has been precoded. As a result, it is possible to notify the wireless receiver of the precoding scheme without increasing the amount of control information. In addition, different precoding schemes can be mixed for each of a plurality of radio receiving apparatuses and used separately.

  (13) A program according to the present invention is a program for controlling a radio reception apparatus that receives a spatially multiplexed signal from a radio transmission apparatus having a plurality of transmission antennas, and transmits the spatially multiplexed signal. A process of receiving group configuration information and group identification information of a group to which the previous wireless reception apparatus belongs, and a process of determining whether or not the own apparatus belongs to the group based on the group configuration information and group identification information If, as a result of the determination, the own device belongs to the group, the computer is caused to execute a series of processes of receiving a signal addressed to the own device corresponding to the precoding scheme determined for each group. It is characterized by that.

  In this way, when the own device belongs to the group, a signal addressed to the own device is received corresponding to the precoding scheme determined for each group, and therefore, the space transmitted from the wireless transmitting device in the wireless receiving device. It is possible to identify from the group what kind of precoding method the multiplexed signal has been precoded. As a result, it is possible to notify the wireless receiver of the precoding scheme without increasing the amount of control information.

  (14) A program according to the present invention is a program for controlling a radio reception apparatus that receives a spatially multiplexed signal from a radio transmission apparatus having a plurality of transmission antennas, and transmits the spatially multiplexed signal. A process of receiving group configuration information and group identification information of a group to which the previous wireless reception apparatus belongs, and a process of determining whether or not the own apparatus belongs to the group based on the group configuration information and group identification information As a result of the determination, when the own device belongs to the group, a series of processes of receiving a signal addressed to the own device corresponding to the precoding scheme determined for each radio receiving device belonging to the group, The computer is executed.

  In this way, when the own device belongs to the group, a signal addressed to the own device is received corresponding to the precoding scheme determined for each radio receiving device belonging to the group. It is possible to identify from the group what kind of precoding method the multiplexed signal has been precoded. As a result, it is possible to notify the wireless receiver of the precoding scheme without increasing the amount of control information.

  (15) An integrated circuit according to the present invention is an integrated circuit that is mounted on a wireless transmission device including a plurality of transmission antennas to cause the wireless transmission device to perform a plurality of functions, and is a plurality of wireless reception devices. A function of transmitting a spatially multiplexed signal, a function of causing each wireless reception device to belong to at least one group, a function of determining a precoding scheme for each group, and any one of the groups A series of functions including a function of selecting a group and a function of performing precoding with the precoding scheme determined for the selected group with respect to transmission data addressed to each wireless reception device belonging to the selected group This is characterized in that the wireless transmission device exhibits the above.

  In this way, since transmission data addressed to each wireless reception device belonging to the selected group is precoded by the precoding scheme determined for the selected group, the wireless reception device It is possible to identify from the group what precoding scheme the transmitted spatial multiplexing signal has been precoded. As a result, it is possible to notify the wireless receiver of the precoding scheme without increasing the amount of control information.

  (16) Further, an integrated circuit according to the present invention is an integrated circuit that is mounted on a wireless transmission device including a plurality of transmission antennas, thereby causing the wireless transmission device to exhibit a plurality of functions, and the plurality of wireless reception devices. A function of transmitting a spatially multiplexed signal with respect to each other, a function of causing each wireless reception device to belong to at least one group, a function of determining a precoding scheme for each wireless reception device belonging to each group, A function of selecting any one group from the group, and a function of performing precoding on transmission data addressed to each wireless reception device belonging to the selected group by a precoding scheme determined for each wireless reception device The wireless transmission device is allowed to exhibit a series of functions.

  As described above, since transmission data addressed to each wireless reception device belonging to the selected group is precoded by the precoding scheme determined for each wireless reception device, the wireless reception device can It is possible to identify from the group what precoding scheme the transmitted spatial multiplexing signal has been precoded. As a result, it is possible to notify the wireless receiver of the precoding scheme without increasing the amount of control information. In addition, different precoding schemes can be mixed for each of a plurality of radio receiving apparatuses and used separately.

  (17) Further, an integrated circuit according to the present invention is an integrated circuit that is mounted on a wireless receiving device, thereby causing the wireless receiving device to exhibit a plurality of functions, and includes a plurality of transmitting antennas. A function of receiving a spatially multiplexed signal, a function of receiving group configuration information and group identification information of a group to which a wireless reception device that is a transmission destination of the spatially multiplexed signal belongs, and the group configuration information and group identification A function for determining whether or not the own device belongs to the group based on the information, and if the own device belongs to the group as a result of the determination, the own device corresponds to the precoding scheme determined for each group. A feature of receiving a signal addressed to the apparatus and a series of functions are provided to the wireless receiving apparatus.

  In this way, when the own device belongs to the group, a signal addressed to the own device is received corresponding to the precoding scheme determined for each group, and therefore, the space transmitted from the wireless transmitting device in the wireless receiving device. It is possible to identify from the group what kind of precoding method the multiplexed signal has been precoded. As a result, it is possible to notify the wireless receiver of the precoding scheme without increasing the amount of control information.

  (18) Further, an integrated circuit according to the present invention is an integrated circuit that is mounted on a wireless receiving device to cause the wireless receiving device to perform a plurality of functions, and includes a plurality of transmitting antennas. A function of receiving a spatially multiplexed signal, a function of receiving group configuration information and group identification information of a group to which a wireless reception device that is a transmission destination of the spatially multiplexed signal belongs, and the group configuration information and group identification A function for determining whether or not the own device belongs to the group based on the information, and a precoding scheme determined for each radio receiving device belonging to the group when the own device belongs to the group as a result of the determination And a function of receiving a signal addressed to its own device in response to the above-described function, and causing the wireless receiving device to exhibit a series of functions.

  In this way, when the own device belongs to the group, a signal addressed to the own device is received corresponding to the precoding scheme determined for each radio receiving device belonging to the group. It is possible to identify from the group what kind of precoding method the multiplexed signal has been precoded. As a result, it is possible to notify the wireless receiver of the precoding scheme without increasing the amount of control information.

  (19) The radio communication system of the present invention includes a plurality of radio reception devices and a radio transmission device that includes a plurality of transmission antennas and transmits spatially multiplexed signals to the plurality of radio reception devices. The wireless transmission device and each wireless reception device each store group configuration information in which each wireless reception device belongs to at least one group and a precoding scheme is determined for each group. The wireless transmission device selects any one group from the groups, transmits group identification information of the selected group, and transmits transmission data addressed to the wireless reception devices belonging to the selected group. On the other hand, a precoding scheme determined for the selected group based on the stored group configuration information Precoding is performed, the precoded signal is spatially multiplexed and transmitted, and the wireless reception device receives the group identification information transmitted by the wireless transmission device, and receives the stored group configuration information and the received Based on the group identification information, it is determined whether or not the own device belongs to the group. If the result of the determination is that the own device belongs to the group, the pre-determined for each group is included in the signal addressed to the own device. A reception process corresponding to a coding method is performed.

  In this way, since transmission data addressed to each wireless reception device belonging to the selected group is precoded by the precoding scheme determined for the selected group, the wireless reception device It is possible to identify from the group what precoding scheme the transmitted spatial multiplexing signal has been precoded. As a result, it is possible to notify the wireless receiver of the precoding scheme without increasing the amount of control information.

  (20) The radio communication system of the present invention includes a plurality of radio reception devices and a radio transmission device that includes a plurality of transmission antennas and transmits spatially multiplexed signals to the plurality of radio reception devices. Each of the wireless reception devices belongs to at least one group, and group configuration information in which a precoding scheme is determined for each wireless reception device belonging to each of the groups, the wireless transmission device and each of the wireless communication devices Each of the wireless reception devices stores, the wireless transmission device selects any one group from each of the groups, transmits group identification information of the selected group, and each wireless reception belonging to the selected group For the transmission data addressed to the device, each radio reception belonging to the selected group is based on the stored group configuration information. Precoding is performed using a precoding scheme determined for each device, and the precoded signal is spatially multiplexed and transmitted, and the wireless reception device receives group identification information transmitted by the wireless transmission device, and Based on the stored group configuration information and the received group identification information, it is determined whether or not the own device belongs to the group, and if the result of the determination is that the own device belongs to the group, The signal is subjected to reception processing corresponding to the precoding scheme determined for the own apparatus in the group.

  As described above, since transmission data addressed to each wireless reception device belonging to the selected group is precoded by the precoding scheme determined for each wireless reception device, the wireless reception device can It is possible to identify from the group what precoding scheme the transmitted spatial multiplexing signal has been precoded. As a result, it is possible to notify the wireless receiver of the precoding scheme without increasing the amount of control information. In addition, different precoding schemes can be mixed for each of a plurality of radio receiving apparatuses and used separately.

  According to the present invention, it is possible to notify a radio reception apparatus whether the multiuser MIMO signal transmitted from the radio transmission apparatus is linear precoding or non-linear precoding without increasing the amount of control information. Become.

It is a figure which shows the schematic structural example of the communication system of this invention. It is a functional block diagram which shows one structural example of the radio | wireless transmitter 100 of this invention. It is a functional block diagram which shows the precoding part 323a which is one structural example of the precoding part 323 which concerns on the 1st Embodiment of this invention. It is a functional block diagram which shows the example of 1 structure of the linear precoding part 401 which concerns on the 1st Embodiment of this invention. It is a functional block diagram which shows the example of 1 structure of the nonlinear precoding part 403 which concerns on the 1st Embodiment of this invention. It is a functional block diagram which shows the example of 1 structure of the radio | wireless receiver 200 which concerns on the 1st Embodiment of this invention. It is a functional block diagram which shows another structural example of the radio | wireless receiver 200 which concerns on the 1st Embodiment of this invention. FIG. 3 is a diagram illustrating an example of group information created by the group configuration unit 307 of the wireless transmission device 100 and shared with the wireless reception device 200 in the first embodiment of the present invention. 2 shows an example of a sequence chart showing an operation between the wireless transmission device 100 and each wireless reception device according to the first embodiment of the present invention. 2 shows an example of a sequence chart showing an operation between the wireless transmission device 100 and each wireless reception device according to the first embodiment of the present invention. It is a functional block diagram which shows the precoding part 323b which is one structural example of the precoding part 323 which concerns on the 2nd Embodiment of this invention. It is a functional block diagram which shows the example of 1 structure of the mixed precoding part 801 which concerns on the 2nd Embodiment of this invention. In the 2nd Embodiment of this invention, it is a figure which shows an example of the group information produced in the group structure part 307 of the radio | wireless transmitter 100, and is shared with the radio | wireless receiver 200. FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
For the communication technology according to the present embodiment, a wireless transmission device (base station device, access point, etc.) selects a plurality of wireless reception devices from a plurality of wireless reception devices (terminal devices) and performs multi-user MIMO transmission. An example will be described of a wireless communication system in which inter-user interference (MUI) that occurs between streams addressed to each wireless reception apparatus is suppressed in advance by linear precoding or non-linear precoding.

  FIG. 1 is a diagram showing a schematic configuration example of a wireless communication system of the present invention. As illustrated in FIG. 1, in the wireless communication system according to the present embodiment, the wireless transmission device 100 includes a plurality of wireless reception devices (for example, wireless reception devices 200-1 to 200-8, wireless reception devices 200-1 to 200-8). Are also referred to as a wireless receiving device 200), the wireless transmitting device 100 creates a plurality of groups by a plurality of combinations of these wireless receiving devices 200, and sets a group identification number (group ID) for identifying the group. Give. One radio receiving apparatus 200 can belong to a plurality of groups. A precoding scheme used for multi-user MIMO transmission is determined for each group. Information on the grouping (information about which group each wireless reception device 200 belongs to), information on the determined precoding scheme, and information defining the processing order of the associated wireless reception device in each group, Prior to communication, the wireless reception device 200 is notified.

  The wireless transmission device 100 selects one of the combinations of the wireless reception devices 200 (target wireless reception devices) to be subjected to multi-user MIMO transmission from the plurality of groups created above that are candidates for the combination. Multi-user MIMO transmission is performed in which transmission data addressed to a plurality of radio reception apparatuses 200 belonging to a group is spatially multiplexed in the same frequency band and simultaneously communicated. At this time, the wireless reception device 200 is notified of the group to be subjected to the multi-user MIMO transmission using a group ID for identifying the selected group. At the same time, the wireless reception device 200 can identify the precoding scheme used by the wireless transmission device 100 by the notification of the group ID. Further, although a communication system using Orthogonal Frequency Division Multiplexing (OFDM) as a transmission method will be described as an example, the present invention is not limited to this.

  Each of the wireless reception devices 200-1 to 200-8 receives a reference signal (a signal known in transmission / reception, such as a pilot signal and a training signal) from the wireless transmission device 100, and each of the transmission antennas of the wireless transmission device 100 and the own wireless device. The propagation path state between each receiving antenna of the receiving apparatus 200 is estimated, and propagation path information representing the propagation path state is reported to the wireless transmission apparatus 100, respectively. Radio transmitting apparatus 100 selects one group from a plurality of groups based on propagation path information and the like reported from each radio receiving apparatus 200, and spatially multiplexes transmission data addressed to the plurality of radio receiving apparatuses 200. Multi-user MIMO transmission for simultaneous communication.

  For example, the propagation path information includes signal power to noise power ratio (SNR), signal power to interference plus noise power ratio (SINR), carrier power to noise power ratio (SINR) Carrier to noise power ratio (CNR), carrier power to interference plus noise power ratio (CINR), or reception quality information (Channel Quality Indicator: CQI) representing the value calculated from them, and radio Channel state information (Channel State Information: CSI) representing the complex channel gain from each transmitting antenna of transmitting apparatus 100 to each receiving antenna of each wireless receiving apparatus 200, its covariance value, or the like, or a desired pre-calculated from the channel state A coding matrix index (Precoding Matrix Index: PMI) or the like is received from each wireless reception device 200, and multi-user MIMO is based on the information. The group of the wireless receiving device 200 to be multiplexed is selected.

  FIG. 2 is a functional block diagram showing a configuration example of the wireless transmission device 100 of the present invention. A configuration example of the wireless transmission device 100 of FIG. 2 includes four antennas, and can transmit multi-user MIMO transmission by spatially multiplexing transmission data addressed to a maximum of four wireless reception devices 200. The wireless reception unit 301 receives signals transmitted from the wireless reception devices 200 (wireless reception devices 200-1 to 200-8) through a plurality of antennas of the antenna unit 303. The control information acquisition unit 305 is a precoding scheme that is received by the wireless reception device 200 that establishes communication for the first time, each wireless reception device 200 that is used when updating the grouping, and the like that is supported by each wireless reception device 200 Information (corresponding information) or type information (terminal class, compliant standard information, receiving function information indicating presence / absence of modulo arithmetic function, etc.) that can identify the corresponding precoding scheme is acquired, and each wireless receiving device 200 is acquired. The corresponding precoding method information is output.

  The group configuration unit 307 creates a plurality of groups based on a plurality of combinations of the wireless reception devices 200 based on at least the corresponding precoding scheme information of the wireless reception devices 200 output from the control information acquisition unit 305, and each group Define the precoding method used in. At this time, the order of the wireless reception devices 200 in each group (the order of propagation path information notification, confirmation response / negative response, etc. in the multiuser MIMO transmission process, the order of spatial streams, etc.) is also determined. One radio receiving apparatus 200 can belong to a plurality of groups. Further, there may be a wireless reception device 200 that does not belong to any group. Further, grouping may be performed by further using information such as position information of each wireless reception device 200 and a result of estimating an arrival angle of a radio wave from each wireless reception device 200. In this case, for example, a group may be created between the wireless reception devices 200 that are separated from each other and the wireless reception devices 200 that are separated from each other in the radio wave arrival angle so that the correlation between the propagation paths becomes low. Further, there may be a plurality of groups in which the precoding scheme and the order of each wireless reception device 200 are different in the combination of the same wireless reception device 200.

  The group storage unit 309 includes group information generated by the group configuration unit 307 (group ID, group wireless communication device 200, precoding scheme to be used, and order of each wireless reception device 200 within the group) ) Is stored. The configuration information generation unit 311 generates group configuration information for notifying each wireless reception device 200 of the group information created by the group configuration unit 307. In addition, the notification of the group configuration information to each wireless reception device 200 includes the wireless reception device 200 belonging to each group (identification information of the wireless reception device 200, that is, user ID, MAC address, etc.), information on the order and the precoding method. You may notify, and you may notify the group which belongs to every radio | wireless receiving apparatus 200, the order in a group, and the information of a precoding system. The propagation path information acquisition unit 313 acquires, from the received signal, propagation path information including CQI and CSI information transmitted by each of the wireless reception devices 200-1 to 200-8.

  The selection unit 315 is based on the transmission data amount and priority addressed to each wireless reception device 200 stored in the transmission buffer unit 317, the propagation path information of each wireless reception device 200 acquired by the propagation path information acquisition unit 313, and the like. Then, a group to which a plurality of radio reception devices 200 (target radio reception devices) multiplexed by multiuser MIMO belongs is selected from the plurality of groups stored in the group storage unit 309. Further, a precoding scheme selection signal indicating a precoding scheme determined in advance corresponding to the selected group is output. Further, based on the CQI from each wireless reception device 200 acquired by the propagation path information acquisition unit 313, such as a modulation scheme and a coding rate (Modulation and Coding Scheme: MCS) for transmission data addressed to each wireless reception device 200 A parameter may be selected. In the present embodiment, a group to which the four terminals of the first to fourth radio receiving apparatuses 200 belong is selected from the radio receiving apparatuses 200-1 to 200-8, and one group (1) is assigned to each radio receiving apparatus 200. A case of transmitting a stream) will be described.

  The transmission buffer unit 317 accumulates transmission data sequences addressed to each wireless reception device 200 input from an upper layer, and stores the transmission data sequences addressed to the first to fourth wireless reception devices 200 selected by the selection unit 315. The data is output to the encoding unit 319. Encoding section 319 performs error correction encoding on the transmission data series addressed to first to fourth radio receiving apparatuses 200 input from transmission buffer section 317, respectively. In addition, when the coding rate of the transmission data addressed to each radio reception apparatus 200 is selected by selection unit 315, rate matching (puncturing) is performed according to the coding rate. When the coding rate is not specified, rate matching may be performed at a predetermined coding rate. Modulation section 321 modulates the transmission data series addressed to first to fourth radio reception apparatuses 200, each of which has been subjected to error correction coding, for each subcarrier addressed to first to fourth radio reception apparatuses 200, respectively. Output modulation symbols. Note that, when the selection unit 315 selects a modulation method for transmission data addressed to each wireless reception device 200, modulation is performed using the modulation method. When there is no designation of a modulation method, it is preferable to perform modulation by a predetermined modulation method.

  The precoding unit 323 receives each modulation symbol addressed to the first to fourth radio reception apparatuses 200 and inputs each modulation symbol based on the CSI from each radio reception apparatus 200 acquired by the propagation path information acquisition unit 313. The modulation symbol is subjected to precoding by a precoding scheme determined corresponding to the group selected by the selection unit 315, and a multiuser MIMO symbol is generated for each of a plurality of antennas of the antenna unit 303 used for transmission. Details of the precoding unit 323 will be described later.

  Reference signal multiplexing section 325 multiplexes the reference signal transmitted from each antenna of antenna section 303 into the multiuser MIMO symbol transmitted from each antenna. Note that the reference signals are preferably multiplexed so that the reference signals transmitted from the respective antennas of the wireless transmission device 100 are received in the respective wireless reception devices 200 in an identifiable manner. Alternatively, it may be multiplexed by frequency division such as division by subcarriers, or may be multiplexed by code division. Also, for the purpose of causing each wireless reception device 200 to estimate the propagation path, when transmitting a sounding signal (sounding frame, sounding packet, null data packet) composed of a reference signal and a control signal that does not include a transmission data sequence The reference signal multiplexing unit 325 directly outputs a reference signal transmitted from each antenna.

  The IFFT unit 327 performs frequency time conversion such as Inverse Fast Fourier Transform (IFFT) on the multi-user MIMO signal for each antenna on which the reference signal is multiplexed, and converts the signal into a time domain signal. . The GI insertion unit 329 inserts a guard interval (GI) in the time domain signal for each antenna. Based on the selection result of the selection unit 315, the identification information generation unit 331 generates group identification information for notifying the wireless reception device 200 of a group identification number (group ID) for identifying the selected group. Further, it may include MCS information and the like for each wireless reception device 200. The wireless transmission unit 333 transmits the signal in which the GI is inserted through each antenna of the antenna unit 303. Also, the group configuration information generated by the configuration information generation unit 311 and the group identification information generated by the identification information generation unit 331 are transmitted through one or more antennas of the antenna unit 303. The control part 335 controls each said part, and performs each process.

  FIG. 3 is a functional block diagram showing a precoding unit 323a which is a configuration example of the precoding unit 323 according to the first embodiment of the present invention. The precoding unit 323a includes a linear precoding unit 401, a non-linear precoding unit 403, and a switching unit 405. The linear precoding unit 401 receives each modulation symbol addressed to the first to fourth radio reception apparatuses 200 and inputs each modulation symbol based on the CSI or PMI of the channel information acquired by the channel information acquisition unit 313. Linear precoding is performed on the modulation symbols. Details of the linear precoding unit 401 will be described later. The nonlinear precoding unit 403 receives each modulation symbol addressed to the first to fourth radio reception apparatuses 200 and inputs each modulation symbol based on the CSI or PMI of the channel information acquired by the channel information acquisition unit 313. Nonlinear precoding is performed on the modulation symbols. Details of the nonlinear precoding unit 403 will be described later.

  The switching unit 405 receives the linear precoding result output from the linear precoding unit 401 and the non-linear precoding result output from the non-linear precoding unit 403 and is based on the precoding scheme selection signal input from the selection unit 315. The first to fourth multiuser MIMO symbols to be transmitted from the respective antennas of the antenna unit 303 are output. In addition, it is preferable that the linear precoding unit 401 and the nonlinear precoding unit 403 do not perform the processing operation when the precoding scheme selection signal does not select the precoding scheme. As a result, power consumption can be reduced.

FIG. 4 is a functional block diagram showing a configuration example of the linear precoding unit 401 according to the first embodiment of the present invention. The linear precoding unit 401 includes a filter calculation unit 501 and a linear filter unit 503. In the example of FIG. 4, a case will be described in which a multiuser MIMO signal is generated by Zero-Forcing precoding based on CSI as linear precoding. The filter calculation unit 501 calculates the complex between each antenna of the wireless transmission device 100 and the antenna of each wireless reception device 200 from the CSI in the propagation channel information of each wireless reception device 200 acquired by the propagation channel information acquisition unit 313. A channel matrix H having a channel gain as an element is generated for each subcarrier, and its inverse matrix H ⁻¹ (or pseudo inverse matrix H ^† = H ^H (HH ^H ) ⁻¹ ) is used as a weighting matrix W that is a linear filter. calculate. The linear filter unit 503 receives the modulation symbols addressed to the first to fourth radio reception apparatuses 200 as input, and multiplies each of the antennas of the antenna unit 303 by the linear filter W calculated by the filter calculation unit 501 for each subcarrier. To output multi-user MIMO symbols to be transmitted respectively.

Thereby, when each radio reception apparatus 200 receives the multiuser MIMO symbol, interference (MUI) due to a signal other than the own radio reception apparatus 200 is canceled by linear precoding, and only the signal addressed to the own radio reception apparatus 200 is received. Is received. In the linear precoding unit 401, an example has been described in which the filter calculation unit 501 calculates and uses an inverse matrix as a linear filter. However, the present invention is not limited to this, and the weight matrix W = H ^H obtained by the MMSE norm is used. (HH ^H + αI) ⁻¹ (I represents a unit matrix, α represents a normalization coefficient) may be used as a linear filter. In this case, the MUI is not completely canceled at the time of reception, but the SINR can be maximized, so that reception characteristics are improved. In a communication system using PMI, the filter calculation unit 501 obtains a weight matrix from the precoding vector indicated by the PMI of each wireless reception device 200 and uses it as a linear filter.

FIG. 5 is a functional block diagram showing a configuration example of the nonlinear precoding unit 403 according to the first embodiment of the present invention. In the example of FIG. 5, a case will be described in which a multiuser MIMO signal is generated by Tomlinson-Harashima precoding (THP) as nonlinear precoding. The QR decomposition unit (interference matrix calculation unit) 601 determines each antenna of the wireless transmission device 100 and each wireless reception device 200 from the CSI in the propagation channel information of each wireless reception device 200 acquired by the propagation channel information acquisition unit 313. A channel matrix H having a complex channel gain with respect to the antenna as an element is generated for each subcarrier, and Hermitian conjugate H ^H of the channel matrix H is subjected to QR decomposition to be unitary matrix Q and upper triangular matrix R. decomposed, further obtains the Hermitian conjugate ^{R H} of the upper triangular matrix R (a lower triangular matrix), the interference matrix ^{B = (diagR H) -1 R} H -I representing the gain of the MUI between the respective radio receiving apparatus 200 It is obtained and output to the interference component calculation unit 603, and the unitary matrix Q is output to the linear filter unit 605. Note that diagX is a matrix having only the diagonal component of the matrix X, and I represents a unit matrix. Here, the interference matrix B takes the form of equation (2).

The first modulo calculation unit 607a performs modulo calculation on the modulation symbol addressed to the first radio reception device 200 generated by the modulation unit 321. Note that, since there is no MUI for the modulation symbol addressed to the first radio reception apparatus 200, the interference component subtraction unit 609 is omitted. Further, the modulo operation unit 607 can be omitted. Based on the interference matrix B obtained by the QR decomposition unit 601, the interference component calculation unit 603 determines that the modulo operation result of the modulation symbol of each subcarrier addressed to the first radio reception device 200 is addressed to the second radio reception device 200. The interference component given to the modulation symbol of each subcarrier is calculated. Here, the element b _{21 in} the second row and first column of the interference matrix B represents the complex gain of interference that the modulation symbol addressed to the first radio reception apparatus 200 has on the modulation symbol addressed to the second radio reception apparatus 200. The interference component can be calculated by multiplying this element by the modulo calculation result of the modulation symbol addressed to the first radio reception apparatus 200.

  The first interference component subtraction unit 609b applies the modulation symbol addressed to the second radio reception device 200 calculated by the interference component calculation unit 603 from the modulation symbol addressed to the second radio reception device 200 generated by the modulation unit 321. The interference component is subtracted for each subcarrier. The second modulo operation unit 607b performs modulo operation on the modulation symbol addressed to the second radio reception apparatus 200 from which the interference component has been subtracted, using a modulo width predetermined by the modulation scheme.

The interference component calculation unit 603 obtains the third modulo calculation result of the modulation symbol of each subcarrier addressed to the first radio reception apparatus 200 and the third modulo calculation result of the modulation symbol of each subcarrier addressed to the second radio reception apparatus 200. The interference component given to the modulation symbol of each subcarrier addressed to the wireless receiver 200 is calculated. Here, the element b _{31 in} the third row and the first column of the interference matrix B represents the complex gain of interference that the modulation symbol addressed to the first radio reception apparatus 200 exerts on the modulation symbol addressed to the third radio reception apparatus 200, and the interference 3 row and second column of elements b ₃₂ of the matrix B is represents the complex gains of the interference modulation symbols of the second radio receiver 200 addressed exerts the modulation symbols of the third wireless reception device 200 destined, these elements The interference component can be calculated by multiplying the modulo calculation result of the modulation symbol addressed to the first radio reception apparatus 200 and the modulo calculation result of the modulation symbol addressed to the second radio reception apparatus 200, respectively.

  The second interference component subtraction unit 609c applies the modulation symbol addressed to the third radio reception device 200 calculated by the interference component calculation unit 603 from the modulation symbol addressed to the third radio reception device 200 generated by the modulation unit 321. The interference component is subtracted for each subcarrier. The third modulo operation unit 607c performs modulo operation on the modulation symbol addressed to the third radio reception apparatus 200 from which the interference component has been subtracted, using a modulo width predetermined by the modulation scheme.

Interference component calculation section 603 obtains the modulo operation result of the modulation symbol of each subcarrier addressed to first radio reception apparatus 200, the modulo operation result of the modulation symbol of each subcarrier addressed to second radio reception apparatus 200, and the third The interference component given to the modulation symbol of each subcarrier addressed to the fourth radio reception apparatus 200 by the modulo calculation result of the modulation symbol of each subcarrier addressed to the radio reception apparatus 200 is calculated. Here, the element b _{41 in} the fourth row and the first column of the interference matrix B represents the complex gain of interference that the modulation symbol addressed to the first radio reception apparatus 200 exerts on the modulation symbol addressed to the fourth radio reception apparatus 200, and Element b _{42 in} the 4th row and 2nd column of matrix B represents the complex gain of interference that the modulation symbol addressed to second radio reception apparatus 200 has on the modulation symbol addressed to fourth radio reception apparatus 200, and 4 of interference matrix B elements b ₄₃ row third column represents the complex gains of the interference modulation symbols of the third wireless reception device 200 destined exerts the modulation symbols of the fourth wireless reception device 200 destined, first each of these elements The interference component can be calculated by multiplying the modulo calculation result of the modulation symbol addressed to the third radio reception apparatus 200 by the modulo calculation result of the modulation symbol addressed to the third radio reception apparatus 200.

  The third interference component subtraction unit 609d applies the modulation symbol addressed to the fourth radio reception device 200 calculated by the interference component calculation unit 603 from the modulation symbol addressed to the fourth radio reception device 200 generated by the modulation unit 321. The interference component is subtracted for each subcarrier. The fourth modulo operation unit 607d performs modulo operation on the modulation symbol addressed to the fourth radio reception apparatus 200 from which the interference component has been subtracted, using a modulo width predetermined by the modulation scheme.

  The linear filter unit 605 outputs the modulo calculation result of the modulation symbol addressed to the first radio reception device 200 output from the first modulo calculation unit 607a and the second radio reception device 200 output from the second modulo calculation unit 607b. Modulo calculation result of the modulation symbol, the modulo calculation result of the modulation symbol addressed to the third radio receiving apparatus 200 output by the third modulo calculation unit 607c, and the fourth radio signal output by the fourth modulo calculation unit 607d. Multi-user MIMO to be transmitted from each antenna of the antenna unit 303 by multiplying the unitary matrix Q calculated by the QR decomposition unit 601 as a linear filter for each subcarrier using the modulo operation result of the modulation symbol addressed to the receiving apparatus 200 as an input Output symbols.

  Thereby, when each radio receiving apparatus 200 receives the multi-user MIMO symbol, interference (MUI) due to a signal other than the own radio receiving apparatus 200 is canceled by THP, and only the signal addressed to the own radio receiving apparatus 200 is received. Is done. In this embodiment, a method using QR decomposition of a channel matrix has been described as an example of a method for realizing THP. However, the present invention is not limited to this, and a method of V-BLAST (Vertical Bell Laboratories Layered Space Time) is used. A method described in Non-Patent Document 5 or the like that uses the sub-optimization of the rearrangement of the wireless reception device 200 in THP may be used.

  FIG. 6A is a functional block diagram showing a configuration example of the wireless reception device 200a according to the first embodiment of the present invention. Note that the wireless reception device 200a and a wireless reception device 200b described later are collectively referred to as a wireless reception device 200. The radio reception device 200a in FIG. 6A is an example of the radio reception device 200 that supports both linear precoding and nonlinear precoding (THP) precoding schemes. The wireless reception unit (reception unit) 701 receives a signal from the wireless transmission device 100 through the antenna unit 703. The configuration information acquisition unit 705 acquires group configuration information notified from the wireless transmission device 100 and outputs the group configuration information to the group storage unit 707. The group storage unit 707 stores the group configuration information acquired by the configuration information acquisition unit 705. The identification information acquisition unit 709 acquires group identification information (group ID) notified from the wireless transmission device 100 and outputs the group identification information (group ID) to the determination unit 711. Further, when the MCS information is included in the group identification information, the MCS information is output to the modulo arithmetic unit (which constitutes a reception processing unit together with the demodulator described later) 713, the demodulator 715a, and the decoder 717. The demodulator 715a and a demodulator 715b described later are collectively referred to as a demodulator 715.

  The determination unit 711 refers to the group configuration information stored in the group storage unit 707 and determines whether or not the own wireless reception device 200a (own station) belongs to the group indicated by the group ID acquired by the identification information acquisition unit 709. The control unit 719 notifies the control unit 719 of the determination result, and when belonging to the group, causes the control unit 719 to execute the following data reception operation. Further, referring to the group configuration information stored in group storage section 707, the group indicated by the acquired group ID is a group that performs multi-user MIMO by linear precoding or a group that performs multi-user MIMO by nonlinear precoding. In the case of linear precoding, the modulo arithmetic unit 713 is instructed not to perform modulo arithmetic, and in the case of non-linear precoding, a signal instructing the modulo arithmetic unit 713 to perform modulo arithmetic is generated. The GI removal unit 721 removes the guard interval (GI) from the received signal.

  The FFT unit 723 performs time-frequency conversion on the received signal from which the GI has been removed by fast Fourier transform (FFT) or the like, and converts it into modulation symbols for each subcarrier. The reference signal separation unit 725 separates the modulation symbol into a received data symbol and a reference signal symbol, and inputs the received data symbol to the propagation path compensation unit 727 and the reference signal symbol to the propagation path estimation unit 729, respectively. To do. The propagation path estimation unit 729, based on the separated reference signal symbols, the propagation path state (complex propagation path gain) between each antenna of the wireless transmission device 100 and the antenna unit 703 of the wireless reception device 200a, The reception quality represented by SNR or SINR is estimated. The propagation path compensation unit 727 performs propagation path compensation (equalization) on the received data symbol based on the propagation path state estimation result in the propagation path estimation unit 729.

  The modulo arithmetic unit 713 receives a modulation method (identification) for a reception data symbol that has been subjected to propagation path compensation when a reception data symbol that has undergone propagation path compensation is input and an instruction signal for performing modulo operation is input from the determination unit 711. When MCS information is input from the information acquisition unit 709, an instruction signal indicating that modulo operation is performed using a modulo operation width (modulo width) determined in advance by the MCS modulation method, and modulo operation is not performed Is input, the propagation data compensated received data symbol is output as it is. Demodulation section 715a demodulates each received data symbol output from modulo operation section 713 (based on the MCS modulation scheme when identification information acquisition section 709 receives MCS information).

  Decoding section 717 performs error correction decoding processing on the demodulated sequence to generate and output a received data sequence. When MCS information is input from the identification information acquisition unit 709, rate matching (depuncture) is performed according to the coding rate of the MCS. Based on the estimated propagation path state, the propagation path information generation unit 731 receives reception quality information (CQI) representing SNR, SINR, CNR, CINR or a value calculated from them, and each transmission antenna of the wireless transmission device 100. A CSI representing a complex channel gain to each receiving antenna of each radio receiving apparatus 200a, a covariance value thereof, and the like is generated. The wireless transmission unit 733 transmits the propagation path information generated by the propagation path information generation unit 731 to the wireless transmission device 100 through the antenna unit 703. The control unit 719 controls each of the above units and executes each process.

  Note that, in this embodiment, when the determination unit 711 determines that the wireless reception device 200 is a group that performs multi-user MIMO by nonlinear precoding, before the demodulation (reception signal point determination) in the demodulation unit 715. The example of the configuration in which the modulo arithmetic unit 713 performs the modulo arithmetic on the received data symbol subjected to propagation path compensation has been described. A configuration example of another radio receiving apparatus 200 is shown in FIG. 6B.

  FIG. 6B is a functional block diagram illustrating a configuration example of the wireless reception device 200b according to the first embodiment of the present invention. The wireless reception device 200b in FIG. 6B does not include the modulo arithmetic unit 713, unlike the wireless reception device 200 in FIG. 6A. When the determination unit 711 determines that the demodulating unit 715b is a group performing multi-user MIMO by nonlinear precoding, the received signal candidate signal point arrangement is wirelessly transmitted due to the influence of the modulo operation in the wireless transmission device 100. Considering that the signal point arrangement at the time of modulation in apparatus 100 is repeated with a modulo width, from the Euclidean distance between the received signal point (with noise added) and each candidate signal point repeated with modulo width. Then, a log likelihood ratio (LLR) of the demodulated bits is calculated (demodulation processing by soft decision). The LLR is input to the decoding unit 717, and error correction decoding is performed. Here, the calculation of the LLR in the demodulator 715b can be calculated by, for example, a known method described in Expression (15) to Expression (20) of Non-Patent Document 6. That is, it can be calculated using an algorithm that calculates the LLR using the Euclidean distance between the received signal point and the candidate signal point close to the received signal point among the candidate signal points repeated with a modulo width. This configuration can be similarly applied to the wireless reception devices 200 of the following embodiments.

  FIG. 7 is a diagram illustrating an example of group information created by the group configuration unit 307 of the wireless transmission device 100 and shared with the wireless reception device 200 in the first embodiment of the present invention. In the example of FIG. 7, two groups using linear precoding (group IDs 1 and 2) and 2 using non-linear precoding are used for the wireless reception devices 200-1 to 200-8. Four groups (one with group IDs 3 and 4) are defined.

  8A and 8B show an example of a sequence chart showing operations between the wireless transmission device 100 and each wireless reception device 200 according to the first embodiment of the present invention. 8A and 8B, the wireless reception devices 200-1, 200-2, and 200-8 are extracted as the wireless reception device 200 and are described as representatives. Further, the group identification information will be described as being included in the control information added to the sounding signal and the multiuser MIMO signal. First, each wireless reception device 200, with respect to the wireless transmission device 100, information on the precoding scheme supported by each wireless reception device 200 (correspondence information), or type information that can identify the corresponding precoding scheme. Correspondence information based on (terminal class, compliance standard information, reception function information indicating presence / absence of modulo arithmetic function, etc.) is transmitted (step S101). Note that the transmission of the correspondence information from each wireless reception device 200 may be performed at an individual timing when communication is established with the wireless transmission device 100 for the first time, or when there is a request from the wireless transmission device 100. .

  The wireless transmission device 100 divides a group in which the wireless reception devices 200 are grouped into a plurality of groups that respectively define precoding schemes used for multiuser MIMO transmission based on correspondence information notified from the wireless reception devices 200. It creates (step S103) and notifies each wireless receiving device 200 of group information (group configuration information) (step S105). After that, radio transmitting apparatus 100 selects a group that performs multi-user MIMO transmission (step S107), generates a sounding signal that includes the group ID for identifying the selected group in the control information (step S109), and transmits it (step S109). Step S111).

  Each wireless reception device 200 receives the above sounding signal, confirms the group ID included in the control information, and determines whether or not the own wireless reception device 200 belongs to the group (step S113). , The propagation path state between the wireless transmission device 100 is estimated based on the reception state of the reference signal included in the sounding signal, and propagation path information representing the propagation path state estimation result is generated. (Step S115), the wireless transmission device 100 is notified (Step S117). In the example of FIGS. 8A and 8B, the case where the wireless reception devices 200-2 and 200-8 belong to the group is illustrated. Further, the notification of the propagation path information is sequentially performed according to the order of each wireless reception device 200 determined in advance in the group.

  The wireless transmission device 100 receives the propagation path information notified from each of the wireless reception devices 200 belonging to the selected group, and based on the received propagation path information using a precoding scheme defined for the selected group. Precoding is performed on the transmission data sequence addressed to each radio receiving apparatus 200 to generate a multiuser MIMO symbol (step S119), and a multiuser MIMO signal to which control information including a group ID for identifying the selected group is added is generated. Transmit (step S121). In addition, it may be recognized as a series of sequences from the sounding signal transmission, and the group ID may not be added when the multiuser MIMO signal is transmitted.

  Each wireless reception device 200 receives the multi-user MIMO signal, checks the group ID included in the control information, and determines whether or not the own wireless reception device 200 belongs to the group (step S123). If it belongs to the group, the multi-user MIMO symbol is received, and data reception processing such as demodulation and error correction decoding is performed (step S125). When no error is detected in the received data, an acknowledgment (Acknowledgement: ACK) is notified to the wireless transmission device 100, and when an error is detected, a negative acknowledgment (Negative Acknowledgment: NAK or NACK) is notified (Step S127). ). Further, the notification of ACK and NAK is sequentially performed according to the order of each wireless reception device 200 determined in advance in the group.

  As described above, according to the present embodiment, in the wireless communication system in which the wireless transmission device 100 selects and uses either linear precoding or nonlinear precoding for each multiuser MIMO transmission, the wireless transmission device Whether the multi-user MIMO signal transmitted from 100 is linear precoding or non-linear precoding can be identified from the group ID, and can be notified to the radio reception apparatus 200 without increasing the amount of control information. It becomes possible.

(Second Embodiment)
As for the communication technique according to the present embodiment, as in the first embodiment, the wireless transmission device 100 selects a plurality of wireless reception devices 200 from the plurality of wireless reception devices 200 and performs multi-user MIMO transmission. An example of a wireless communication system in which MUI generated between streams addressed to wireless reception apparatus 200 is suppressed in advance by linear precoding or non-linear precoding will be described. In the present embodiment, linear nonlinear mixed precoding that can select and mix linear precoding or non-linear precoding for each of a plurality of radio receiving apparatuses 200 that transmit data simultaneously in multiuser MIMO transmission. A wireless communication system using the above will be described as an example.

  In the wireless communication system according to the present embodiment, as in the first embodiment, when the wireless transmission device 100 communicates with a plurality of wireless reception devices 200 (for example, wireless reception devices 200-1 to 200-8), wireless transmission is performed. The apparatus 100 creates a plurality of groups by a plurality of combinations of these radio reception apparatuses 200, and determines a precoding scheme used for multi-user MIMO transmission for each of these groups. Information is notified to the wireless reception device 200 prior to communication, and is shared by the wireless transmission device 100 and the wireless reception device 200. However, unlike the first embodiment, radio reception apparatuses 200 with different precoding schemes used for multi-user MIMO transmission may be mixed in the same group, and in this case, each radio reception apparatus in the group. The information of the precoding method used for the stream addressed to 200 is also notified to each radio receiving apparatus 200 and shared prior to communication. One radio receiving apparatus 200 can belong to a plurality of groups.

  Thereafter, as in the first embodiment, the wireless transmission device 100 creates a plurality of combinations of the wireless reception devices 200 (target wireless reception devices) that are the targets of multi-user MIMO transmission created above as candidates for the combinations. One of the groups is selected, and multi-user MIMO transmission is performed in which transmission data addressed to a plurality of radio receiving apparatuses 200 belonging to the selected group is spatially multiplexed in the same frequency band and simultaneously communicated. At this time, the wireless reception device 200 is notified of the group to be subjected to the multi-user MIMO transmission using a group ID for identifying the selected group. At the same time, the wireless reception device 200 can identify the precoding scheme used by the wireless transmission device 100 by the notification of the group ID.

  The configuration of the wireless transmission device 100 according to the present embodiment is the same as that of the wireless transmission device 100 of FIG. 2 of the first embodiment, and the configuration of the precoding unit 323 is different. Further, the processes in the selection unit 315, the group configuration unit 307, and the group storage unit 309 are different. Hereinafter, description of the same parts as those of the first embodiment will be omitted, and different parts will be described.

  The selection unit 315 is based on the propagation path information of each wireless reception device 200 acquired by the propagation path information acquisition unit 313 and the transmission data amount and priority addressed to each wireless reception device 200 accumulated in the transmission buffer unit 317. Then, a group to which a plurality of wireless reception devices 200 multiplexed by multiuser MIMO belongs is selected from a plurality of groups stored in group storage unit 309. In addition, a precoding scheme selection signal indicating a precoding scheme determined in advance for each radio reception apparatus 200 corresponding to the selected group is output. Further, based on the CQI from each wireless reception device 200 acquired by the propagation path information acquisition unit 313, such as a modulation scheme and a coding rate (Modulation and Coding Scheme: MCS) for transmission data addressed to each wireless reception device 200 A parameter may be selected. In the present embodiment, the group to which the four terminals of the first to fourth radio reception apparatuses 200 belong is selected from the radio reception apparatuses 200-1 to 200-8, and the selected groups are the first and the second groups. It is assumed that the second wireless receiver 200 is a group of linear non-linear precoding using a linear precoding scheme and the third and fourth radio receivers 200 are using a non-linear precoding scheme. A case will be described in which a sequence (one stream) is transmitted.

  The group configuration unit 307 in the present embodiment creates a plurality of groups by a plurality of combinations of the wireless reception devices 200 based on at least the corresponding precoding scheme information of the wireless reception devices 200 output from the control information acquisition unit 305. The precoding scheme used in each group is determined for each group or for each radio reception apparatus 200. One radio receiving apparatus 200 can belong to a plurality of groups. Further, grouping may be performed by further using information such as position information of each wireless reception device 200 and a result of estimating an arrival angle of a radio wave from each wireless reception device 200. In this case, for example, a group may be created between the wireless reception devices 200 that are separated from each other and the wireless reception devices 200 that are separated from each other in the radio wave arrival angle so that the correlation between the propagation paths becomes low. In addition, there may be a plurality of groups in which the precoding scheme and order of each wireless reception device 200 are different in the combination of the same wireless reception device 200.

  The group storage unit 309 includes information on the group created by the group configuration unit 307 (group ID, the wireless reception device 200 to which the group belongs, the precoding method used for each wireless reception device 200, and each wireless reception device 200 in the group. Group configuration information including the order of The precoding unit 323 has each modulation symbol addressed to a plurality of radio reception devices 200 (here, a case where the first to fourth radio reception devices 200 belong) belonging to the group selected by the selection unit 315 are described. Each radio signal determined corresponding to the group selected by the selection unit 315 for each input modulation symbol based on the CSI from each radio reception apparatus 200 that is input and acquired by the propagation path information acquisition unit 313 Precoding is performed on the modulation symbols addressed to each radio receiving apparatus 200 by the precoding scheme for receiving apparatus 200, and multi-user MIMO symbols are generated for each of a plurality of antennas of antenna section 303 used for transmission.

  FIG. 9 is a functional block diagram showing a precoding unit 323b which is a configuration example of the precoding unit 323 according to the second embodiment of the present invention. The precoding unit 323b includes a linear precoding unit 401, a nonlinear precoding unit 403, a mixed precoding unit 801, and a switching unit 803. The linear precoding unit 401 and the non-linear precoding unit 403 are shown in FIGS. 4 and 5, respectively, as in the first embodiment. The operation of the mixed precoding unit 801 will be described later. The switching unit 803 receives the linear precoding result output from the linear precoding unit 401, the nonlinear precoding result output from the nonlinear precoding unit 403, and the linear nonlinear mixed precoding result output from the mixed precoding unit 801. Then, one of the results is selected based on the precoding scheme selection signal input from the selection unit 315, and first to fourth multiuser MIMO symbols to be transmitted from the antennas of the antenna unit 303 are output. To do. In addition, it is preferable that the linear precoding unit 401, the nonlinear precoding unit 403, and the mixed precoding unit 801 do not perform the processing operation when the precoding scheme selection signal does not select its own precoding scheme. As a result, power consumption can be reduced.

  FIG. 10 is a functional block diagram showing a configuration example of the mixed precoding unit 801 according to the second embodiment of the present invention. In the example of FIG. 10, based on the precoding scheme selection signal for each radio reception apparatus 200 input from the selection unit 315, for each radio reception apparatus 200, the linear precoding and the Tomlinson-Harashima pre-coding as the non-linear precoding are performed. A case will be described in which one of the coding (THP) is selected and mixed to generate a multiuser MIMO signal.

  The mixed precoding unit 801 in FIG. 10 performs basically the same operation as the non-linear precoding unit 403 shown in FIG. 5, but receives the precoding scheme selection signal from the selection unit 315, and the first to fourth Modulo calculation is performed in first to fourth modulo calculation units 901a to 901d (hereinafter, the first to fourth modulo calculation units 901a to 901d are also referred to as modulo calculation units 901) corresponding to each wireless reception device 200. Whether or not to perform the switching is switched by a precoding method selection signal. Specifically, the modulo operation unit 901 corresponding to the radio reception apparatus 200 in which the precoding method selection signal indicates linear precoding does not perform modulo operation, and the precoding method selection signal indicates non-linear precoding. A modulo operation unit 901 corresponding to the receiving device 200 performs modulo operation. In the case of the example of the present embodiment, the first modulo arithmetic unit 901a and the second modulo arithmetic unit 901b corresponding to the first and second radio receiving apparatuses 200 respectively pass the signal as it is without performing the modulo arithmetic. The third modulo arithmetic unit 901c and the fourth modulo arithmetic unit 901d corresponding to the third and fourth radio receiving apparatuses 200 respectively perform modulo arithmetic on the signal from which the interference component is subtracted.

  In the present embodiment, as the configuration of the precoding unit 323b, a configuration including three precoding units including a linear precoding unit 401, a nonlinear precoding unit 403, and a mixed precoding unit 801 has been described. Even a configuration including only such a mixed precoding unit 801 can be realized. In this case, if the precoding scheme selection signal from selection section 315 selects linear precoding for all radio reception apparatuses 200 (modulo calculation is not performed in modulo calculation section 901), it is equivalent to linear precoding. If multi-user MIMO symbols are obtained and nonlinear precoding is selected for all radio reception apparatuses 200 (modulo computation unit 901 performs modulo computation), multi-user MIMO symbols equivalent to nonlinear precoding are obtained.

  The configuration of the wireless reception device 200 in this embodiment is the same as that of the wireless reception device 200 in FIG. 6 in the first embodiment, and the processing in the determination unit 711 is different. Hereinafter, description of the same parts as those of the first embodiment will be omitted, and different parts will be described. The determination unit 711 refers to the group configuration information stored in the group storage unit 707 and determines whether or not the own wireless reception device 200 (own station) belongs to the group indicated by the group ID acquired by the identification information acquisition unit 709. Determination is made, and the determination result is notified to the control unit 719, and when belonging to the group, the data reception operation is executed through the control unit 719. Further, with reference to the group configuration information stored in the group storage unit 707, it is determined whether the precoding scheme of the local station in the group indicated by the acquired group ID is linear precoding or non-linear precoding, and linear precoding is performed. In the case of coding, the modulo arithmetic unit 713 is instructed not to perform modulo arithmetic, and in the case of nonlinear precoding, a signal instructing the modulo arithmetic unit 713 to perform modulo arithmetic is generated.

  FIG. 11 is a diagram illustrating an example of group information created by the group configuration unit 307 of the wireless transmission device 100 and shared with the wireless reception device 200 in the second embodiment of the present invention. In the example of FIG. 11, two groups using linear precoding (group IDs 1 and 2) and two using non-linear precoding are used for radio reception apparatuses 200-1 to 200-8 as precoding methods. Six groups are defined: groups (groups with group IDs 3 and 4) and two groups (groups with group IDs 5 and 6) in which radio receivers 200 of linear precoding and nonlinear precoding are mixed. .

  The wireless transmission device 100 selects a plurality of wireless reception devices 200 to be subjected to multi-user MIMO transmission based on propagation path information reported from each wireless reception device 200, and includes the plurality of wireless reception devices 200. Group to be extracted and one group is selected. Alternatively, based on the propagation path information reported from each radio reception apparatus 200, first, a group (accordingly, a precoding scheme) is selected, and the radio reception apparatus 200 belonging to the selected group is set as a target of multiuser MIMO transmission. You may choose.

  As described above, according to the present embodiment, for each multi-user MIMO transmission, the wireless transmission device 100 selects one of linear precoding, nonlinear precoding, and a mixture of linear and nonlinear precoding. In such a wireless communication system, it is possible to identify from the group ID whether the multiuser MIMO signal transmitted from the wireless transmission device 100 is linear precoding or non-linear precoding, thereby increasing the amount of control information The wireless reception device 200 can be notified without doing so.

  The program that operates in the communication apparatus according to the present invention may be a program that controls a CPU (Central Processing Unit) or the like (a program that causes a computer to function) so as to realize the functions of the above-described embodiments related to the present invention. Information handled by these devices is temporarily stored in RAM (Random Access Memory) during the processing, and then stored in various ROMs such as Flash ROM (Read Only Memory) and HDD (Hard Disk Drive). Reading, correction, and writing are performed by the CPU as necessary. 2 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed, whereby the processing of each unit is performed. May be performed. Here, the “computer system” includes an OS and hardware such as peripheral devices.

  The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system. Further, part or all of the communication devices (wireless transmission device 100 and wireless reception device 200) in the above-described embodiment may be realized as an LSI that is typically an integrated circuit. Each functional block of the communication device may be individually chipped, or part or all of them may be integrated into a chip. Further, the method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. In addition, when an integrated circuit technology that replaces LSI appears due to progress in semiconductor technology, an integrated circuit based on the technology can also be used.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the invention may be changed in design without departing from the gist of the present invention. Is also included.

100 wireless transmission device 200, 200-1 to 200-8, 200a, 200b wireless reception device 301 wireless reception unit 303 antenna unit 305 control information acquisition unit 307 group configuration unit 309 group storage unit 311 configuration information generation unit 313 propagation path information acquisition Unit 315 selection unit 317 transmission buffer unit 319 encoding unit 321 modulation unit 323, 323a, 323b precoding unit 325 reference signal multiplexing unit 327 IFFT unit 329 GI insertion unit 331 identification information generation unit 333 wireless transmission unit 335 control unit 401 linear pre Coding unit 403 Nonlinear precoding unit 405 Switching unit 501 Filter calculation unit 503 Linear filter unit 601 QR decomposition unit 603 Interference component calculation unit 605 Linear filter unit 607 Modulo operation unit 607a First modulo operation unit 607b Second mode Juro operation unit 607c Third modulo operation unit 607d Fourth modulo operation unit 609 Interference component subtraction unit 609b First interference component subtraction unit 609c Second interference component subtraction unit 609d Third interference component subtraction unit 701 Radio reception unit 703 Antenna unit 705 Configuration information acquisition unit 707 Group storage unit 709 Identification information acquisition unit 711 Determination unit 713 Modulo operation units 715, 715a, 715b Demodulation unit 717 Decoding unit 719 Control unit 721 GI removal unit 723 FFT unit 725 Reference signal separation unit 727 propagation path compensation section 729 propagation path estimation section 731 propagation path information generation section 733 wireless transmission section 801 mixed precoding section 803 switching section 901 modulo computation section 901a first modulo computation section 901b second modulo computation section 901c third Modulo operation unit 901d Fourth modulo performance Part

Claims (8)

A wireless transmission device that includes a plurality of transmission antennas and performs multi-user MIMO transmission that simultaneously transmits transmission data addressed to a plurality of wireless reception devices by spatial multiplexing,
Group configuration for creating a plurality of groups representing a combination of the plurality of radio receiving apparatuses when performing multi-user MIMO transmission and predetermining a precoding scheme for each group as either linear precoding or non-linear precoding And
Generate group configuration information that represents the configuration of each of the plurality of groups, and notifies the plurality of wireless reception apparatuses in advance of associations between group identification information for identifying the plurality of groups and the determined precoding scheme. A configuration information generation unit;
A selector for selecting any one of a group from the plurality of groups,
An identification information generating unit for generating group identification information of the selected group;
The transmission data of the respective radio receiving apparatus destined belonging to the selected group, and a precoding section that performs precoding with the precoding scheme the previously determined for the selected group,
Prior to transmission of the precoded signal, the group configuration information is transmitted to the plurality of wireless reception devices in advance, and the group identification information together with the precoded signal is transmitted to each of the wireless reception devices belonging to the selected group. radio transmitting apparatus characterized that you send to. The group configuration unit further determines a precoding scheme in advance for each wireless reception device belonging to each group for each group,
The precoding unit precodes transmission data addressed to each wireless reception device belonging to the selected group in a precoding scheme predetermined for each wireless reception device corresponding to the selected group. The wireless transmission device according to claim 1, wherein: 2. The plurality of groups , wherein a plurality of wireless reception devices of the same combination belong, and a plurality of groups having different orders in the group of the plurality of wireless reception devices to which the plurality belong belong. The wireless transmission device according to claim 2. A wireless reception device that receives a multi-user MIMO signal in which transmission data addressed to a plurality of wireless reception devices is spatially multiplexed and transmitted simultaneously from a wireless transmission device having a plurality of transmission antennas,
Information indicating a configuration of a group to which the plurality of radio reception apparatuses to which the multi-user MIMO signal is transmitted belongs, group identification information for identifying the group, and linear precoding or nonlinear precoding for the group Prior to receiving the multi-user MIMO signal, group configuration information including an association with a precoding scheme determined in advance in either one of the plurality of radio receptions serving as a transmission destination of the multi-user MIMO signal A receiving unit that receives the group identification information of a group to which a device belongs together with the multi-user MIMO signal;
A determination unit that determines whether the own device belongs to the group indicated by the group identification information based on the group configuration information and the group identification information;
As a result of the determination, when the own device belongs to the group indicated by the group identification information, the received multiuser MIMO signal corresponds to a precoding scheme determined in advance for the group indicated by the group identification information. A wireless reception device comprising: a reception processing unit that performs reception processing. The group configuration information includes information on association between the group identification information and a precoding scheme determined in advance for each of the plurality of wireless reception devices belonging to the group,
If the reception processing unit belongs to the group indicated by the group identification information as a result of the determination, the reception processing unit responds to the received multiuser MIMO signal corresponding to the group indicated by the group identification information. 5. The radio reception apparatus according to claim 4, wherein reception processing corresponding to a precoding scheme determined in advance is performed . 6. The radio reception according to claim 4, wherein the reception processing unit performs a modulo operation on a data symbol of the received multiuser MIMO signal when the precoding scheme is nonlinear precoding. apparatus. By being mounted to the radio transmitting apparatus Ru comprising a plurality of transmitting antennas, an integrated circuit to exhibit a plurality of functions to the wireless transmission device,
A function of performing multi-user MIMO transmission for spatially multiplexing transmission data addressed to a plurality of wireless reception devices and transmitting signals simultaneously;
A function of creating a plurality of groups representing a combination of the plurality of radio receiving apparatuses when performing multi-user MIMO transmission, and predetermining a precoding scheme as either linear precoding or non-linear precoding for each group; ,
Generate group configuration information that represents the configuration of each of the plurality of groups, and notifies the plurality of wireless reception apparatuses in advance of associations between group identification information for identifying the plurality of groups and the determined precoding scheme. Function and
A function of selecting any one group from the plurality of groups;
A function of generating group identification information of the selected group;
A function of performing precoding with respect to transmission data addressed to each wireless reception device belonging to the selected group by the predetermined precoding scheme for the selected group;
Prior to transmission of the precoded signal, the group configuration information is transmitted to the plurality of wireless reception devices in advance, and the group identification information together with the precoded signal is transmitted to each of the wireless reception devices belonging to the selected group. An integrated circuit characterized by causing the wireless transmission device to exhibit a series of functions including: An integrated circuit that, when mounted on a wireless receiver, causes the wireless receiver to perform a plurality of functions,
A function of receiving, from a wireless transmission device having a plurality of transmission antennas, a multiuser MIMO signal in which transmission data addressed to a plurality of wireless reception devices is spatially multiplexed and transmitted simultaneously;
Information indicating a configuration of a group to which the plurality of radio reception apparatuses to which the multi-user MIMO signal is transmitted belongs, group identification information for identifying the group, and linear precoding or nonlinear precoding for the group A function of receiving, prior to receiving the multi-user MIMO signal, group configuration information including an association with a precoding scheme determined in advance in either one of the following:
A function of receiving the group identification information of a group to which the plurality of wireless reception devices to which the multi-user MIMO signal is transmitted belongs together with the multi-user MIMO signal;
A function of determining whether the own device belongs to the group indicated by the group identification information based on the group configuration information and the group identification information;
As a result of the determination, when the own device belongs to the group indicated by the group identification information, the received multiuser MIMO signal corresponds to a precoding scheme determined in advance for the group indicated by the group identification information. An integrated circuit characterized by causing the wireless reception device to exhibit a series of functions including a reception processing function.

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