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US 11,652,680 B1Granted
Waveform independent coarse synchronization method
AssigneeBAE Systems Information and Electronic Systems Integration Inc.
InventorsMatthew J. Sherman, Bassem Scander
Life of this patent
Estimating the term…
Abstract
A wideband chaotic waveform that is rateless in that it may be modulated at virtually any rate and has a minimum of features introduced into the waveform. Further, the waveform provided may be operated below a signal to noise ratio wall to further enhance the LPD and LPE aspects, thereof. Additionally, the present disclosure may provide a mix of coherent and non-coherent processing techniques applied to signal samples to efficiently achieve coarse synchronization with a waveform that is faster, more efficient and more accurate than using time domain signal correlators alone.
Claims19
A method of waveform synchronization comprising:
- receiving a signal via at least one antenna and at least one receiver, the signal having a known preamble and wherein the data used in generating the signal are not known except for the data symbols in the preamble;
- creating a plurality of coherence domains using time and frequency constraints to accept maximum uncompensated Doppler values;
- establishing a plurality of FFT bins in each of plurality of coherence domains;
- performing a series of bulk correlations on the received signal by multiplying the received signals with a reference signal derived from the known preamble in the frequency domain and applying an inverse fast Fourier transform (FFT) to the result to estimate the correlation values at points in time;
- detecting and isolating the preamble of the received signal;
- estimating the synchronization values of the received signal within the coherence domains based on the known preamble;
- estimating the synchronization values of the received signal between coherence domains based on the known preamble;
- and
- updating the synchronization values of the received signal on an ongoing and real time basis using the estimated synchronization values from the detected signal from a post processing feedback loop.
6 more elements
A method of secure communications within an environment comprising:
- generating a communications signal with at least a portion of the signal being known and at least a portion of the signal being unknown;
- transmitting the communications signal from a first platform via at least one antenna in operable communication with at least one transmitter;
- receiving the communications signal with a second platform via at least one antenna in operable communication with at least one receiver;
- creating a plurality of coherence domains using time and frequency constraints to accept maximum uncompensated Doppler values;
- establishing a plurality of FFT bins in each of plurality of coherence domains;
- estimating the synchronization values of the communications signal within the coherence domains based on the known portion of the communications signal;
- estimating the synchronization values of the received signal between coherence domains based the known portion of the communications signal;
- and
- updating the synchronization values of the communications signal on an ongoing and real time basis using the estimated synchronization values from the detected signal from a post processing feedback loop.
6 more elements
A system comprising:
- at least one antenna;
- at least one receiver in operable communication with the at least one antenna, the at least one antenna and at least one receiver operable to receive and transmit electromagnetic signals;
- at least one processor capable of executing logical functions in communication with the at least one antenna and at least one receiver;
- and
- at least one non-transitory computer readable storage medium having instructions encoded thereon that, when executed by the processor, implements operations to generate a waveform, the instructions including:
- receive a signal via the at least one antenna and the at least one receiver, the signal having a known preamble and wherein the data used in generating the signal are not known except for the data symbols in the preamble;
- create a plurality of coherence domains using time and frequency constraints to accept maximum uncompensated Doppler values;
- establish a plurality of FFT bins in each of plurality of coherence domains;
- perform a series of bulk correlations on the received signal by multiplying the received signals with a reference signal derived from the known preamble in the frequency domain and applying an inverse fast Fourier transform (FFT) to the result to estimate the correlation values at points in time;
- detect and isolate the preamble of the received signal;
- estimate the synchronization values of the received signal within the coherence domains based on the known preamble;
- estimate the synchronization values of the received signal between coherence domains based on the known preamble;
- and
- update the synchronization values of the received signal on an ongoing and real time basis using the estimated synchronization values from the detected signal from a post processing feedback loop.
11 more elements
Dependencies are inferred from the claim text.