Wireless communication system, wireless communication apparatus, wireless communication method, and computer program

• US 7,477,695 B2
• Filed: 02/07/2005
• Issued: 01/13/2009
• Est. Priority Date: 02/18/2004
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Takano, Hiroaki
• Primary Examiner(s): Tran; Khai
• Application Number:
  US11/050,731
• Publication Number:
  US 20050190850A1
• Time in Patent Office: 1,436 Days
• Field of Search: 375/267, 375/269, 375/347, 375/299, 375/346, 375/261, 455/101, 455/132, 370/332, 370/334, 370/338
• US Class Current: 375/261
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0634 Antenna weights or vector/matrix coefficients

Abstract

An SVD-MIMO transmission compresses the amount of information to be fed back to a transmitter from a receiver. The transmitter and the receiver share a representation form of (amplitude, phase) for representing data to be transmitted, i.e., a form of converting real data into complex data. In other words, transmitted data is allocated to a signal point in the signal space corresponding to the data value for data transmission. The data receiver extracts an original data value according to a combination of amplitude and phase at a received signal point. The receiver can compress the information amount of transmission data.

Claims

1. A wireless communication system, comprising:

a transmitter and a receiver sharing a representation form of (amplitude, phase) for representing data to be transmitted;

a data transmission side transmits data by allocating it to a signal point in a signal space corresponding to a data value; and

a data reception side extracts an original data value according to a combination of amplitude and phase at a receive signal point,

wherein said system adopt employs a space division multiplexing communication to multiplex signals for communication using a pair of transmitters and receivers each having a plurality of antennas; and

including,

singular value decomposition means for acquiring channel matrix H from a transmitter to a receiver in space division multiplexing, performing a singular value decomposition for said channel matrix into UDV^H, and finding transmission antenna weight matrix V including, as element vectors, transmission weight vectors for each transmission antenna;

transmission antenna weight matrix feedback means for allocating element vectors constituting transmission antenna weight matrix V to a signal point in a signal space for encoding and feeding an encoded signal from said receiver back to said transmitter;

weight matrix reception means for allowing said transmitter to decode element vectors from a combination of amplitude and phase at a received signal point and restore transmission antenna weight matrix V, and for appending a reference signal to an encoded signal for transmission; and

wherein said weight matrix reception means receives transmission antenna weight matrix V by removing fluctuations on a transmission path based on said reference signal.

2. A wireless communication apparatus, sharing a representation form of (amplitude, phase) for representing data to be transmitted with a communication destination comprising:

encoding means for allocating transmission data to a signal point in a signal space corresponding to a data value for encoding;

transmission means for transmitting an encoded signal;

a plurality of antennas;

reception means for receiving a multiplexed signal from a transmitter having a plurality of antennas;

channel estimation means for finding channel matrix H from a reference signal transmitted from a transmitter;

singular value decomposition means for performing a singular value decomposition for channel matrix H into UDV^H to acquire reception weight matrix U, diagonal matrix D, and transmission weight matrix V;

encoding means for allocating element vectors constituting transmission antenna weight matrix V to a signal point in a signal space for encoding; and

transmission antenna weight matrix feedback means for feeding said encoded signal back to said transmitter and for appending a reference signal to an encoded signal for transmission.

3. A wireless communication method of using a plurality of antennas to receive a multiplexed signal from a transmitter having a plurality of antennas, said method comprising:

finding channel matrix H from a reference signal transmitted from a transmitter;

performing a singular value decomposition for channel matrix H into UDV^H to acquire reception weight matrix U, diagonal matrix D, and transmission weight matrix V;

allocating element vectors constituting transmission antenna weight matrix V to a signal point in a signal space for encoding; and

feeding said encoded signal back to said transmitter.

4. A computer-readable storage medium encoded with computer program instructions which cause a computer to perform a process for using a plurality of antennas to receive a multiplexed signal from a transmitter having a plurality of antennas, comprising:

finding channel matrix H from a reference signal transmitted from a transmitter;

performing a singular value decomposition for channel matrix H into UDV^H to acquire reception weight matrix U, diagonal matrix D, and transmission weight matrix V;

allocating element vectors constituting transmission antenna weight matrix V to a signal point in a signal space for encoding; and

feeding said encoded signal back to said transmitter.