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

• US 10,673,655 B2
• Filed: 06/24/2019
• Issued: 06/02/2020
• 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, Takano, Hiroaki
• Primary Examiner(s): Tse, Young T
• Application Number:
  US16/449,454
• Publication Number:
  US 20190312754A1
• Time in Patent Office: 344 Days
• Field of Search: 375260, 375262, 375265, 375267, 375295, 370208, 370210, 370344
• 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. A first electronic device having a first spatial multiplexing decoding capability, comprising:

circuitry configured to receive and process a data packet including preamble signals, training signals and data signals in this order, wherein

the training signals are weighted by weights included in a weight matrix for spatial multiplexing, the weight matrix being set to weight the data signals to be transmitted on an Orthogonal Frequency-Division Multiplexing (OFDM) sub-carrier from a second electronic device to the first electronic device, the training signals being received from the second electronic device before the data signals on the OFDM sub-carrier;

the preamble signals are for use of at least one of signal detection, synchronization or adjustment of gain at the first electronic device;

the training signals are used to estimate channel state;

a number of the training signals which are sequentially received is determined based on information associated with the first spatial multiplexing decoding capability being transmitted to the second electronic device before receiving the data packet; and

the weight matrix is calculated using a maximum signal to noise ratio, a zero-forcing, or a singular value decomposition.

2. The first electronic device of claim 1, wherein the circuitry is further configured to transmit a first packet in response to receiving a second packet from the second electronic device before receiving the data packet, the first packet including the information associated with the first spatial multiplexing decoding capability.

3. The electronic device of claim 2, wherein the first packet includes reference signals, a number of the reference signals being determined according to the first spatial multiplexing decoding capability.

4. The first electronic device of claim 2, wherein the first packet is a Clear-To-Send (CTS) packet and the second packet is a Request-To-Send (RTS) packet.

5. The first electronic device of claim 1, further comprising antenna nodes configured to receive the data packet from the second electronic device,

wherein the first spatial multiplexing decoding capability corresponds to a number of the antenna nodes.

6. The first electronic device of claim 5, wherein the antenna nodes include a first antenna node and a second antenna node, and

the training signals include:

a first training signal weighted by a first weight corresponding to a channel through the first antenna node; and

a second training signal weighted by a second weight corresponding to a channel through the second antenna node.

7. The first electronic device of claim 6, wherein the data signals include a first data signal weighted by the first weight and a second data signal weighted by the second weight, and

the first training signal and the second training signal are received with timing difference, whereas

the first data signal and the second data signal are simultaneously received.

8. The first electronic device of claim 6, wherein the first training signal is received before the second training signal.

9. The first electronic device of claim 5, wherein the number of antenna nodes for receiving spatial multiplexing signals is two.

10. The first electronic device of claim 5, wherein the second electronic device has a second spatial multiplexing decoding capability that corresponds to a number of antenna nodes of the second electronic device, and

the number of the antenna node of the second electronic device for transmitting spatial multiplexing signals is larger than the number of the antenna node of the first electronic device for receiving the spatial multiplexing signals transmitted by the second electronic device.

11. The first electronic device of claim 10, wherein the number of the antenna nodes of the first electronic device for receiving the spatial multiplexing signals is two,

and the antenna nodes are coupled to two antennas.

12. The first electronic device of claim 1, wherein the circuitry is configured to estimate the channel state based on the training signals received from the second electronic device.

13. The first electronic device of claim 1, wherein the weight matrix is generated based on the channel state between the first electronic device and the second electronic device.

14. The first electronic device of claim 13, wherein the weight matrix is generated by the second electronic device.

15. The first electronic device of claim 14, wherein the circuitry is further configured to transmit reference signals to the second electronic device prior to receiving the data packet, and

the weight matrix is generated by the second electronic device based on the channel state estimated by using the reference signals.

16. The first electronic device of claim 1, wherein the second electronic device has a second spatial multiplexing decoding capability, and

the second spatial multiplexing decoding capability is larger than the first spatial multiplexing decoding capability.

17. The first electronic device of claim 1, wherein the preamble signals are not weighted by the weights included in the weight matrix prior to receiving the training signals on the OFDM sub-carrier.

18. The first electronic device of claim 1, wherein the circuitry is configured to use the preamble signals for the signal detection, the synchronization and the adjustment of gain at the first electronic device.

19. An electronic device having a spatial multiplexing decoding capability, comprising:

circuitry configured to;

receive information from another electronic device, the information including a spatial multiplexing decoding capability of the another electronic device; and

transmit a data packet including preamble signals, training signals and data signals in this order to the another electronic device, on an Orthogonal Frequency-Division Multiplexing (OFDM) sub-carrier,

wherein the circuitry is further configured to;

generate the preamble signals used for at least one of signal detection, synchronization or adjustment of gain for the another electronic device; and

generate the training signals weighted by weights included in a weight matrix for spatial multiplexing, the weight matrix being set to weight the data signals to be transmitted on the OFDM sub-carrier from the electronic device to the another electronic device, the training signals being used to estimate channel state, and a number of the training signals being determined based on the spatial multiplexing decoding capability of the another electronic device,

wherein each of the training signals is transmitted to the another electronic device at different timings, and

wherein the weight matrix is calculated using a maximum signal to noise ratio, a zero-forcing, or a singular value decomposition.

20. The electronic device according to claim 19, wherein the circuitry is further configured to generate the weight matrix associated with the channel state between the another electronic device and the electronic device.

21. The electronic device according to claim 20, wherein the circuitry is further configured to preform calibration of reference signals transmitted from the another electronic device to the electronic device.

22. The electronic device according to claim 21, wherein the circuitry is further configured to perform the calibration for dependence of the reference signals on characteristics of an analogue RF circuitry of at least one of the another electronic device or the electronic device.

23. The electronic device according to claim 20, wherein the circuitry is further configured to determine the weight matrix without receiving information representing the weight matrix from the another electronic device.

24. The electronic device according to claim 20, wherein the circuitry is further configured to estimate the channel state between the another electronic device and the electronic device based on reference signals transmitted from the another electronic device so as to generate the weight matrix.

25. The electronic device of claim 19, wherein the preamble signals are not weighted by the weights included in the weight matrix.

26. The electronic device of claim 19, further comprising antenna nodes configured to transmit the data packet to the another electronic device,

wherein the spatial multiplexing decoding capability of the electronic device corresponds to a number of the antenna nodes.

27. The electronic device of claim 26, wherein the antenna nodes includes three antenna nodes.

28. The electronic device of claim 19, wherein the preamble signals are for use of the signal detection, the synchronization and the adjustment of gain at the another electronic device.