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

• US 8,718,009 B2
• Filed: 08/05/2013
• Issued: 05/06/2014
• Est. Priority Date: 11/05/2003
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kuroda, Shinichi
• Primary Examiner(s): TAYLOR, BARRY W
• Application Number:
  US13/959,151
• Publication Number:
  US 20130322380A1
• Time in Patent Office: 274 Days
• Field of Search: 370/329, 370/334, 455/562.1
• US Class Current: 370/329
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0421 utilizing implicit feedback, e.g. steered pilot signals
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/06 at the transmitting station
• CPC Class Codes: H04B 7/0619 using feedback from receiving side feedback signaling for adaptive modulation/coding H04L1/0001
• CPC Class Codes: H04B 7/0665 Feed forward of transmit weights to the receiver
• CPC Class Codes: H04B 7/0854 using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion
• CPC Class Codes: H04B 7/0862 receiver computing weights based on information from the transmitter
• CPC Class Codes: H04L 1/0656 Cyclotomic systems, e.g. Bell Labs Layered Space-Time [BLAST]
• CPC Class Codes: H04L 2025/0377 during the reception of training signals
• CPC Class Codes: H04L 25/0202 Channel estimation
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 27/12 Modulator circuits; Transmitter circuits
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management

Abstract

In performing SVD-MIMO transmission, a set-up procedure is simplified while assuring a satisfactory decoding capability with a reduced number of antennas. A transmitter estimates channel information based on reference signals sent from a receiver, determines a transmit antenna weighting coefficient matrix based on the channel information, calculates a weight to be assigned to each of components of a multiplexed signal, and sends, to the receiver, training signals for respective signal components, the training signals being weighted by the calculated weights. On the other hand, the receiver determines a receive antenna weighting coefficient matrix based on the received training signals.

Claims

1. An electronic device comprising:

circuitry configured to

set a weight matrix for weighting data signals to be transmitted on a Orthogonal Frequency-Division Multiplexing (OFDM) sub-carrier;

control transmission of training signals weighted by weights included in the weight matrix prior to controlling the transmission of data signals on the sub-carrier; and

control transmission of preamble signals that are not weighted by the weights included in the weight matrix prior to controlling the transmission of the training signals on the sub-carrier, wherein

the training signals are used to estimate channel state information at another electronic device, and the preamble signals are for at least one of signal detection synchronization or adjustment of gain at the another electronic device.

2. The electronic device of claim 1, wherein the circuitry is further configured to:

control transmission of a Request-To-Send (RTS) signal; and

control starting transmission of the training signals after receiving a Clear-To-Send (CTS) signal received from another electronic device in response to the RTS signal.

3. The electronic device of claim 1, further comprising:

a plurality of antennas via which the training signals, the data signals and the preamble signals are transmitted.

4. The electronic device of claim 3, wherein

a number of rows included in the weight matrix corresponds to a number of the plurality of antennas.

5. The electronic device of claim 4, wherein

the weight matrix includes at least a first weight and a second weight, and

the circuitry is configured to weight signals transmitted via a first antenna of the plurality of antennas with the first weight and signals transmitted via a second antenna of the plurality of antennas with the second weight.

6. The electronic device of claim 5, wherein

the training signals include at least a first training signal and a second training signal, and

the circuitry is configured to weight the first training signal with the first weight and the second training signal with the second weight.

7. The electronic device of claim 6, wherein the first training signal and the second training signal are transmitted according to a time division method.

8. The electronic device of claim 3, wherein the plurality of antennas include three antennas.

9. The electronic device of claim 1, wherein the circuitry is configured to generate the weight matrix based on channel state information between the electronic device and another electronic device.

10. The electronic device of claim 9, wherein the circuitry is configured to estimate the channel state information based on reference signals received from the another electronic device, wherein the number of the reference signals is determined according to the number of antennas at the another electronic device.

11. The electronic device of claim 10, wherein the circuitry is configured to calibrate the channel state information to obtain channel information of a channel from the electronic device to the another electronic device.

12. The electronic device of claim 1, wherein

the data signals and the training signals are transmitted as a concatenated frame.

13. A mobile apparatus comprising:

a plurality of antennas; and

circuitry configured to

set a weight matrix for weighting data signals to be transmitted on a Orthogonal Frequency-Division Multiplexing (OFDM) sub-carrier;

control transmission of training signals weighted by weights included in the weight matrix prior to controlling the transmission of data signals on the sub-carrier; and

control transmission of preamble signals that are not weighted by the weights included in the weight matrix prior to controlling the transmission of the training signals on the sub-carrier, wherein

the training signals are used to estimate channel state information at another electronic device, and the preamble signals are for at least one of signal detection synchronization or adjustment of gain at the another electronic device.

14. The mobile apparatus of claim 13, wherein

a number of rows included in the weight matrix corresponds to a number of the plurality of antennas.

15. The mobile apparatus of claim 14, wherein

the weight matrix includes at least a first weight and a second weight, and

the circuitry is configured to weight signals transmitted via a first antenna of the plurality of antennas with the first weight and signals transmitted via a second antenna of the plurality of antennas with the second weight.

16. The mobile apparatus of claim 15, wherein

the training signals include at least a first training signal and a second training signal, and

the circuitry is configured to weight the first training signal with the first weight and the second training signal with the second weight.

17. The mobile apparatus of claim 13, wherein

the plurality of antennas include three antennas.

18. The mobile apparatus of claim 13, wherein

the circuitry is configured to generate the weight matrix based on channel state information between the mobile apparatus and another electronic device.

19. The mobile apparatus of claim 18, wherein

the circuitry is configured to estimate the channel state information based on reference signals received from the another electronic device, wherein the number of the reference signals is determined according to the number of antennas at the another electronic device.

20. A method performed by an electronic device, the method comprising:

setting, by circuitry of the electronic device, a weight matrix for weighting data signals to be transmitted on a Orthogonal Frequency-Division Multiplexing (OFDM) sub-carrier;

controlling, by the circuitry, transmission of training signals weighted by weights included in the weight matrix prior to controlling the transmission of data signals on the sub-carrier; and

controlling, by the circuitry, transmission of preamble signals that are not weighted by the weights included in the weight matrix prior to controlling the transmission of the training signals on the sub-carrier, wherein

the training signals are used to estimate channel state information at another electronic device, and the preamble signals are for at least one of signal detection synchronization or adjustment of gain at the another electronic device.

21. The method of claim 20, further comprising:

generating the weight matrix based on channel state information between the electronic device and the another electronic device.

22. The method of claim 21, further comprising:

estimating the channel state information based on reference signals received from the another electronic device, wherein the number of the reference signals is determined according to the number of antennas at the another electronic device.

23. A non-transitory computer-readable medium including computer program instructions, which when executed by an electronic device, cause the electronic device to:

set a weight matrix for weighting data signals to be transmitted on a Orthogonal Frequency-Division Multiplexing (OFDM) sub-carrier;

control transmission of training signals weighted by weights included in the weight matrix prior to controlling the transmission of data signals on the sub-carrier;

control transmission of preamble signals that are not weighted by the weights included in the weight matrix prior to controlling the transmission of the training signals on the sub-carrier, wherein

the training signals are used to estimate channel state information at another electronic device, and the preamble signals are for at least one of signal detection synchronization or adjustment of gain at the another electronic device.