Patent ID: 11863359
Assignee: AMAZON TECHNOLOGIES, INC.
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 5:
6. A method comprising:
receiving, by a first receiver and a second receiver of a first device from a second device, first data using radio frequency (RF) signals modulated according to a digital multi-carrier modulation scheme that defines a set of data subcarriers in a wireless channel, wherein a first data subcarrier and a second data subcarrier of the set of data subcarriers operate at a first amplitude value;
measuring a first fast Fourier transform (FFT) response of the RF signals across the set of data subcarriers at the first receiver and a second FFT response of the RF signals across the set of data subcarriers at the second receiver;
determining, by the first device from the first FFT response and the second FFT response, a first received signal power level corresponding to the first data subcarrier and a second received signal power level corresponding to the second data subcarrier;
generating a first value based on the first received signal power level being lower than a threshold value and a second value based on the second received signal power level not being lower than the threshold value, the threshold value representing a frequency selective fading characteristic of the wireless channel;
sending, by the first device to the second device, second data comprising the first value indicative of the first received signal power level corresponding to the first data subcarrier and the second value indicative of a second received signal power level corresponding to the second data subcarrier; and
receiving, by the first device from the second device, third data using the digital multi-carrier modulation scheme in which the first data subcarrier operates at a second amplitude value and the second data subcarrier operates at the first amplitude value.