US 12,316,479 B2
Calculation of the metric for selecting the type of modulation in subcarriers for an OFDM signal
Abylay Sargaskayev, Almaty (KZ); Konstantin Tiutin, Almaty (KZ); Denis Kazimirov, Almaty (KZ); Andrey Vasilchenko, Almaty (KZ); and Ilya Rubanov, Almaty (KZ)
Assigned to VR UNIBLOCK INC., San Francisco, CA (US)
Filed by VR UNIBLOCK INC., San Francisco, CA (US)
Filed on Mar. 23, 2023, as Appl. No. 18/189,077.
Prior Publication US 2024/0323057 A1, Sep. 26, 2024
Int. Cl. H04L 25/02 (2006.01); H04L 27/26 (2006.01)
CPC H04L 25/0242 (2013.01) [H04L 25/0224 (2013.01); H04L 27/26025 (2021.01)] 16 Claims
OG exemplary drawing
 
1. A method for selecting a modulation type for a group of subcarriers in a radio frequency (RF) receiver with orthogonal frequency division multiplexing (OFDM), the method comprising:
receiving an RF transmitted signal, wherein the RF transmitted signal includes a set of subcarriers;
obtaining a series of digital samples from the RF transmitted signal;
converting the series of digital samples into a corresponding set of frequency domain signals;
obtaining a complex frequency response of a set of transmission channels based on pilot data contained in the of frequency domain signals, the obtaining the complex frequency response of the set of transmission channels comprises:
interpolating the pilot data and correcting a corresponding phase of the pilot data according to a calculated Doppler shift;
calculating a signal to noise ratio (SNR) metric from an amplitude frequency response of the complex frequency response in the set of subcarriers;
calculating dynamic threshold values of the SNR metric from collected statistics of data recovery in a decoder, wherein each dynamic threshold value of the dynamic threshold values is associated with a corresponding modulation type, and is useable for switching the modulation type;
switching the modulation type in the set of subcarriers based on the SNR metric and the dynamic threshold values; and
transmitting an updated modulation map to a transmitter.