Ranging with simultaneous frames

A device, comprising:

• multiple transceivers to an external node, wherein the multiple transceivers each having a transceiver clock, the multiple transceivers are configured to:
• receive a message from the external node, wherein the message is received by each of the multiple transceivers;
• transmit by each of the multiple transceivers a respective data frame to the external node in response to the message;
• wherein:
• each transceiver initiates the transmission of its respective data frame a predetermined time period after receipt of the message by the transceiver;
• the predetermined time period is the same for each of the transmitted data frames;
• the transmissions of the data frames from the plurality of transceivers overlap;
• a non-transitory computer readable medium that stores computer executable instructions;
• at least one processor, wherein when the at least one processor executes the computer executable instructions, the at least one processor is configured to:
• generate, for each of the multiple transceivers, the respective data frame, wherein:
• each of the data frames comprises a first training sequence and a second training sequence, and for each of the respective data frame:
• the first training sequence is located at the start of the respective data frame;
• and
• the second training sequence comprises a cryptographically generated training sequence;
• wherein a transmission timing of each of the transceiver is based on a respective clock of the transceiver;
• and
• adjusting a clock frequency of one or more of the transceiver clocks to adjust a carrier frequency offset (CFO) of a respective transceiver, wherein the clock frequency is adjusted based on a detected CFO of an earlier transmission received from the external node.

A device for communication with an external node, comprising:

• at least one transceiver configured to:
• send a message to the external node;
• receive signals corresponding to a plurality of overlapping data frames transmitted by respective transceivers of the device in response to the message;
• a non-transitory computer readable medium that stores computer executable instructions;
• at least one processor, wherein when the at least one processor executes the computer executable instructions, the at least one processor is configured to:
• identify a particular one of the respective data frames and acquiring data of the identified data frame based on a first training sequence included in each of the respective data frame, wherein the respective first training sequences start at respective different start times with respect to a reception time of the message at a respective transceiver;
• and
• acquire data of the identified frame comprises detecting a second training sequence contained in each of the data frames, the second training sequences of the data frames comprising cryptographically generated training sequences and starting at a common time offset from the reception time of the message at each of the respective transceivers;
• and
• determine the reception time of the frame based on detection of the second training sequence and using the determined reception time to compute a distance between the device and external node.