Time-reversal wireless systems having asymmetric architecture

Patent metadata

Field	Value
Publication number	US-9882675-B2
Application number	US-201313969271-A
Country	US
Kind code	B2
Filing date	Aug 16, 2013
Priority date	Aug 16, 2013
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

In an asymmetric time-reversal wireless system, a base station includes an input circuit configured to, during a hand-shake period, receive a channel response signal derived from a probe signal sent from a first terminal device to the apparatus through multiple wireless propagation paths, and during an uplink transmission period, receive combined signals that include a signal from the first terminal device and a signal from a second terminal device. The base station includes a data processor configured to calculate a signature waveform for the first terminal device based on the channel response, and determine the signal sent from the first terminal device during the uplink transmission period based on the combined signals and the signature waveform for the first terminal device.

First claim

What is claimed is:

1. A method comprising:
at a transceiver, receiving a channel response signal derived from a probe signal sent from a first device to the transceiver through multiple wireless propagation paths;
at the transceiver, calculating a signature waveform for the first device based on the channel response;
at the transceiver, receiving combined signals that include a first signal from the first device and a second signal from a second device, wherein
the first device comprises a first antenna, a first data source, and a first encoder,
the second device comprises a second antenna, a second data source, and a second encoder,
the first signal is derived from first data from the first data source and encoded by the first encoder, the first signal is transmitted by the first device at a first frequency band, and
the second signal is derived from second data from the second data source and encoded by the second encoder, the second signal is transmitted by the second device at a second frequency band, in which a first particular frequency is common to both the first and second frequency bands and a second particular frequency of the first frequency band is not in the second frequency band; and

at the transceiver, determining the first signal from the first device based on the combined signals and the signature waveform for the first device.

2. The method of claim 1 in which determining the signal from the first device comprises, at the transceiver, performing a convolution operation, or an operation equivalent to the convolution operation, between the combined signals and the signature waveform for the first device.

3. The method of claim 1 in which determining the signal from the first device comprises filtering the combined signals using the signature waveform as a filtering parameter.

4. The method of claim 1 in which the signature waveform for the first device is a time-reversed waveform of the channel response signal derived from the probe signal sent from the first device.

5. The method of claim 4 in which the channel response signal is represented as h(t) and the signature waveform for the first device is represented as h*(T−t), t representing time, and representing a delay spread of the multiple propagation paths.

6. The method of claim 4 in which the channel response signal is represented as h[k] and the signature waveform for the first device is represented as h*[L−k], k being an integer, and L representing a delay spread of the multiple propagation paths.

7. The method of claim 1 , comprising transmitting, from the transceiver to the first receiver and a second receiver, a combined downlink signal derived from a combination of a first downlink waveform and a second downlink waveform, the first downlink waveform including data intended for the first device, the second downlink waveform including data intended for the second device.

8. The method of claim 7 , comprising generating the first downlink waveform based on the data intended for the first device and the signature waveform for the first device.

9. The method of claim 8 in which generating the first downlink waveform comprises performing a convolution of the data intended for the first device and the signature waveform for the first device.

10. The method of claim 7 in which the combined downlink signal is configured to enable each of the first device and the second device to receive multipath signals that can be used determine a data signal intended for the device, the first and second devices receiving the downlink signal through different propagation paths and determining different data signals.

11. The method of claim 1 in which the transceiver is part of a base station.

12. The method of claim 1 in which receiving combined signals comprises receiving combined signals that include signals from three or more devices communicating with the transceiver, each of the devices being associated with a corresponding signature waveform.

13. The method of claim 1 in which the first device does not calculate the signature waveform.

14. The method of claim 1 in which the first device does not perform any signal processing that uses the signature waveform.

15. A method of communication between a transceiver and multiple devices using wireless multi-path signals, the method comprising:
performing a hand-shake process between the transceiver and the devices, in which for each device, the transceiver receives a channel response signal derived from a probe signal sent from the device to the transceiver through multiple propagation paths;
at the transceiver, calculating a signature waveform for each of the devices based on the channel response derived from the probe signal sent from the device;
at the transceiver, receiving a combined uplink signal that includes uplink signals from two or more devices, wherein each of the devices comprises an antenna, a data source, and an encoder, and each of the uplink signals is derived from data from a respective data source and encoded by a respective encoder, in which at least two uplink signals are transmitted by respective devices at two frequency bands in which a first particular frequency is common to the two frequency bands and a second particular frequency of one of the two frequency bands is not in the other of the two frequency bands; and
at the transceiver, determining the uplink signal from each one of the devices based on the combined uplink signal and the signature waveform for the device.

16. The method of claim 15 in which the transceiver is part of a base station.

17. The method of claim 15 in which the devices do not calculate any signature waveform.

18. The method of claim 15 in which the devices do not perform any signal processing that uses the signature waveform.

19. A method of asymmetric time-reversal communication between a plurality of devices using wireless multi-path signals, the method comprising:
performing a first hand-shake process between the first and second devices, in which the first device receives a channel response signal derived from a probe signal sent from the second device to the first device through multiple wireless propagation paths;
performing a second hand-shake process between the first and third devices, in which the first device receives a channel response signal derived from a probe signal sent from the third device to the first device through multiple wireless propagation paths;
at the first device, calculating a signature waveform for the second device based on the channel response derived from the probe signal sent from the second device;
at the first device, calculating a signature waveform for the third device based on the channel response derived from the probe signal sent from the third device;
at the first device, receiving a combined uplink signal that includes a second uplink signal from the second device and a third uplink signal from the third device, wherein
the second device comprises a second antenna, a second data source, and a second encoder,
the third device comprises a third antenna, a third data source, and a third encoder,
the second uplink signal is derived from second data from the second data source and encoded by the second encoder, the second uplink signal is transmitted by the second device at a second frequency band, and
the third uplink signal is derived from third data from the third data source and encoded by the third encoder, the third uplink signal is transmitted by the third device at a third frequency band, in which a first parti

Assignees

• Origin Wireless Inc

Inventors

• Han Feng
• Liu K J Ray

Classifications

• H04L1/00 Primary

  Arrangements for detecting or preventing errors in the information received {(correcting synchronisation H04L7/00)} · CPC title

• H04L25/03343

  Arrangements at the transmitter end · CPC title

• H04L25/0224 Primary

  using sounding signals · CPC title