WIRELESS COMMUNICATION APPARATUS, WIRELESS COMMUNICATION SYSTEM, AND WIRELESS COMMUNICATION METHOD
First Claim
1. :
- A wireless communication apparatus of a base station used in a wireless communication system that can perform multiplex communication between a plurality of user equipments and the base station, the wireless communication apparatus comprising;
a channel estimation unit which is adapted to perform channel estimation of a propagation path from the user equipment to the wireless communication apparatus;
a scheduling unit which is adapted to select a pair of user equipments that perform the multiplex communication based on a result of the channel estimation;
a precoding selection unit which is adapted to determine a precoding matrix of a projection matrix that is applied to a channel response matrix of one user equipment in order to make channel response matrices of the respective user equipments orthogonal or almost orthogonal to each other in the selected pair of user equipments;
a control information notification unit which is adapted to feed back control information that includes precoding information that indicates the determined precoding matrix to the corresponding user equipments;
a reception unit which is adapted to receive data transmitted from the respective user equipments of the selected pair of user equipments through a plurality of reception antennas;
a signal separation unit which is adapted to separate the received data to detect a plurality of streams; and
a decoding unit which is adapted to decode reception data from the plurality of detected streams.
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Accused Products
Abstract
Interference between users in an MU-MIMO system is minimized by effective precoding, without increasing an overhead of control data. In a wireless communication system in which multiplex communication is possible between multiple UE1, UE2, and BS, a channel estimation and precoding selection unit 539 in BS estimates channels from the respective UE1, UE2 to the BS, determines a precoding matrix P from a projection matrix to make the two channel response matrices orthogonal or nearly orthogonal, and feeds back the precoding matrix P to UE2, and executes precoding on only UE2 of the two. A precoding unit 524 in the UE2 employs the precoding matrix P that has been notified to perform precoding of a data stream, and sends the precoded data stream to the BS.
76 Citations
14 Claims
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1. :
- A wireless communication apparatus of a base station used in a wireless communication system that can perform multiplex communication between a plurality of user equipments and the base station, the wireless communication apparatus comprising;
a channel estimation unit which is adapted to perform channel estimation of a propagation path from the user equipment to the wireless communication apparatus; a scheduling unit which is adapted to select a pair of user equipments that perform the multiplex communication based on a result of the channel estimation; a precoding selection unit which is adapted to determine a precoding matrix of a projection matrix that is applied to a channel response matrix of one user equipment in order to make channel response matrices of the respective user equipments orthogonal or almost orthogonal to each other in the selected pair of user equipments; a control information notification unit which is adapted to feed back control information that includes precoding information that indicates the determined precoding matrix to the corresponding user equipments; a reception unit which is adapted to receive data transmitted from the respective user equipments of the selected pair of user equipments through a plurality of reception antennas; a signal separation unit which is adapted to separate the received data to detect a plurality of streams; and a decoding unit which is adapted to decode reception data from the plurality of detected streams. - View Dependent Claims (2, 3, 4, 5, 6, 7)
- A wireless communication apparatus of a base station used in a wireless communication system that can perform multiplex communication between a plurality of user equipments and the base station, the wireless communication apparatus comprising;
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8. :
- A wireless communication apparatus of a user equipment used in a wireless communication system that can perform multiplex communication between a plurality of user equipments and a base station, the wireless communication apparatus comprising;
a space multiplexing unit which is adapted to generate a plurality of streams for performing space multiplexing among a plurality of transmission antennas as data that is to be transmitted to the base station; a precoding unit which is, in a case where precoding information is notified, which indicates a precoding matrix of a projection matrix that is applied to a channel response matrix of one user equipment in order to make channel response matrices of the respective user equipments orthogonal or almost orthogonal to each other in a pair of user equipments that perform the multiplex communication based on control information that is fed back from the base station, adapted to perform precoding by applying the precoding matrix with respect to the plurality of streams; and a transmission unit which is adapted to transmit the plurality of streams to which the precoding process has been subjected through the plurality of transmission antennas. - View Dependent Claims (9, 10)
- A wireless communication apparatus of a user equipment used in a wireless communication system that can perform multiplex communication between a plurality of user equipments and a base station, the wireless communication apparatus comprising;
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11. :
- (canceled)
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12. :
- (canceled)
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13. :
- A wireless communication method in a wireless communication system that can perform multiplex communication between a plurality of user equipments and the base station, the wireless communication method comprising the steps of
performing channel estimation of a propagation path from the user equipment to the own apparatus; selecting a pair of user equipments that perform the multiplex communication based on a result of the channel estimation; determining a precoding matrix of a projection matrix that is applied to a channel response matrix of one user equipment in order to make channel response matrices of the respective user equipments orthogonal or almost orthogonal to each other in the selected pair of user equipments; feeding control information that includes precoding information that indicates the determined precoding matrix back to the corresponding user equipments; receiving data transmitted from the respective user equipments of the selected pair of user equipments through a plurality of reception antennas; separating the received data to detect a plurality of streams; and decoding reception data from the plurality of detected streams.
- A wireless communication method in a wireless communication system that can perform multiplex communication between a plurality of user equipments and the base station, the wireless communication method comprising the steps of
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14. :
- A wireless communication method in a wireless communication system that can perform multiplex communication between a plurality of user equipments and a base station, the wireless communication method comprising the steps of;
generating a plurality of streams for performing space multiplexing among a plurality of transmission antennas as data that is to be transmitted to the base station; performing precoding, in a case where precoding information is notified, which indicates a precoding matrix of a projection matrix that is applied to a channel response matrix of one user equipment in order to make channel response matrices of the respective user equipments orthogonal or almost orthogonal to each other in a pair of user equipments that perform the multiplex communication based on control information that is fed back from the base station, by applying the precoding matrix to the plurality of streams; and transmitting the plurality of streams to which the precoding process has been subjected through the plurality of transmission antennas.
- A wireless communication method in a wireless communication system that can perform multiplex communication between a plurality of user equipments and a base station, the wireless communication method comprising the steps of;
Specification