SYSTEMS AND METHODS FOR REAL-TIME CALIBRATION OF RADIO DELAYS

1 . A method comprising:

transmitting a stimulus signal to a software defined radio (SDR) operating in a first state;

receiving, via the SDR, an output signal based upon the transmitted stimulus signal;

determining, based upon the received output signal, a delay state of the SDR from a plurality of predetermined delay states of the SDR, wherein the delay state is associated with a parameter of the SDR, and wherein the parameter includes any one or more of a receive frequency, transmit frequency or bandwidth;

generating a calibrated signal based upon the determined delay state; and

sending, to the SDR, the calibrated signal to operate in a second state with an adjusted time.

2 . The method of claim 1 , further comprising:

receiving another output signal from the SDR operating in the second state; and

determining, based upon the received other output, another delay state of the SDR from among the plurality of predetermined delay states of the SDR.

3 . The method of claim 2 , further comprising:

generating another calibrated signal based upon the other state; and

transmitting the other calibration signal to the SDR for operating in a third state.

4 . The method of claim 1 , wherein the predetermined delay states are obtained by:

collecting, prior to the transmitting step, a plurality of signals output from the SDR; and

characterizing the parameter for each of the collected signals.

5 . The method of claim 1 , wherein the stimulus signal includes a radio frequency signal and a pulse per second (PPS) signal.

6 . The method of claim 1 , wherein the stimulus signal include a GNSS waveform.

7 . The method of claim 1 , wherein the delay state ranges between 12.5 ps/° C. and −3.5 ps/° C.

8 . The method of claim 1 , where the calibrated signal is a function of an operating temperature of the SDR.

9 . The method of claim 1 , wherein the calibrated signal is a sub-nanosecond signal measured.

10 . A system comprising:

non-transitory memory including instructions stored thereon; and

a processor operably coupled to the non-transitory memory, wherein the processor is configured to execute the instructions including:

causing a transmission of a stimulus signal to a software defined radio (SDR) operating in a first state;

causing a reception of an output signal from the SDR based upon the transmitted stimulus signal;

determining, based upon the received output signal, of a delay state of the SDR from a plurality of predetermined delay states of the SDR, wherein the delay state is associated with a parameter of the SDR; and

causing to generate a calibrated signal based upon the determined delay state.

11 . The system of claim 10 , wherein the processor is further configured to execute the instructions of causing to send the calibrated signal to the SDR.

12 . The system of claim 10 , further comprising:

a signal generator and a clock/calibration module.

13 . The system of claim 12 , wherein the processor, the signal generator and the clock/calibration module are housed in a single casing.

14 . The system of claim 10 , wherein the parameter includes any one or more of a receive frequency, transmit frequency or bandwidth.

15 . A system comprising a software defined radio (SDR), wherein the SDR is configured to execute a set of instructions including:

sending, while in a first state, an output signal to a remote system, wherein the output signal indicates a delay state associated with a parameter of the SDR;

receiving, from the remote system, a calibrated signal; and

updating, based upon the calibrated signal, to a second state from the first state.

16 . The system of claim 15 , further comprising:

the remote system,

wherein the SDR and remote system are co-located in a satellite.

17 . The system of claim 16 , wherein the satellite exhibits a temperature ranging between −20° C. and 50° C.

18 . The system of claim 17 , wherein the satellite exhibits an internal pressure of about 10 −5 Torr.

19 . The system of claim 15 , wherein the parameter includes any one or more of a receive frequency, transmit frequency or bandwidth.

20 . The system of claim 15 , where the calibrated signal is a function of an operating temperature of the SDR.