Time-reversal wireless systems having asymmetric architecture

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.

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 particular frequency is common to the second frequency band and the third frequency band, and a second particular frequency of the second frequency band is not in the third frequency band;
• at the first device, determining the second uplink signal from the second device based on the combined uplink signal and the signature waveform for the second device;
• and
• at the first device, determining the third uplink signal from the third device based on the combined uplink signal and the signature waveform for the third device.