Rapid low-complexity synchronization and doppler correction in 5G/6G

A method for a user device of a wireless network to communicate with a base station of the wireless network, the method comprising:

• a) configuring a transmission resource grid and a reception resource grid, wherein each grid, of the transmission resource grid and the reception resource grid, comprises symbol-times in time and subcarriers in frequency, the symbol-times and subcarriers according to a clock of the user device;
• b) determining a downlink propagation time interval comprising a time interval for a downlink signal to propagate from a transmitter in the base station to a receiver in the user device;
• c) retarding the symbol-times of the reception resource grid, relative to symbol-times of a base station resource grid, by the downlink propagation time interval;
• d) determining a round-trip propagation time interval comprising the downlink propagation time interval plus a time interval for an uplink signal to propagate from a transmitter of the user device to a receiver of the base station;
• e) advancing the symbol-times of the transmission resource grid, relative to the symbol-times of the reception resource grid, by the round-trip propagation time interval;
• f) transmitting, according to the transmission resource grid, an uplink message to the base station;
• g) receiving, according to the reception resource grid, a downlink message from the base station;
• h) transmitting, according to the transmission resource grid, a further uplink data message to the base station;
• i) wherein the further uplink data message comprises message elements, each message element of the further uplink data message comprising a received time and a received frequency, as received by the base station;
• j) wherein, for each message element of the further uplink data message, the received time is configured, by the user device, to be aligned with a symbol-time of the base station resource grid;
• and
• k) wherein, for each message element of the further uplink data message, the received frequency is configured, by the user device, to be aligned with a subcarrier of the base station resource grid.