Methods for fast and low-power UWB IR baseband receiver synchronization

A method of synchronizing a device to a signal, comprising:

• selecting a number N as a function of an available number of repetitions of a predetermined code;
• receiving a signal comprising a plurality of pulse frames and a plurality of pulses that represent N, wherein each pulse frame comprises a number L of discrete possible pulse positions, wherein at least one pulse in the plurality of pulses is located at an actual pulse position within the plurality of pulse frames, and wherein N is less than or equal to L;
• sampling the signal to obtain N samples, wherein the N samples comprise at least one sample at each of the L discrete possible pulse positions;
• correlating the N samples with a plurality of rotated versions of the predetermined code to determine a first correlation;
• comparing the first correlation value with a noise threshold to determine if a signal is present;
• sampling the signal to obtain N times two samples, wherein the N times two samples comprise at least one sample at each of the L times two discrete possible pulse positions;
• correlating the N times two samples with a plurality of rotated versions of the predetermined code to determine a second correlation;
• and
• based on the second correlation, determining the actual pulse position of the at least one pulse and a code phase of the signal, wherein the code phase is a phase of the signal with respect to the predetermined code.

A method, comprising:

• selecting a sampling delay;
• receiving a signal comprising a plurality of pulse frames and a plurality of pulses that represent a number N selected as a function of an available number of repetitions of a predetermined code, wherein each pulse frame comprises a number L of discrete possible pulse position and at least one pulse in the plurality of pulses is located at an actual pulse position within the plurality of pulse frames, and wherein N is less than or equal to L;
• sampling the signal to obtain a first set of N samples covering at least the length of the predetermined code, wherein the first set of samples comprises at least one sample at each of the L discrete possible pulse positions;
• correlating the first set of samples with rotated versions of the predetermined code to obtain a first set of correlation values;
• comparing each correlation value in the set of correlation values with a noise threshold to determine if a signal is present;
• if a signal is not present, repeating the method with a new sampling delay;
• and
• if a signal is present, confirming the presence of the signal, wherein confirming the presence of the signal comprises:
• resampling the signal with the sampling delay to obtain a second set of samples covering at least the length of the predetermined code;
• and
• correlating the second set of values with the rotated versions of the predetermined code to determine if a signal is present.

A method, comprising:

• selecting a sampling delay;
• receiving a signal comprising a plurality of pulse frames and a plurality of pulses that represent a number N selected as a function of an available number of repetitions of a predetermined code, wherein each pulse frame comprises a number L of discrete possible pulse position and at least one pulse in the plurality of pulses is located at an actual pulse position within the plurality of pulse frames, and wherein N is less than or equal to L;
• sampling the signal to obtain a first set of N samples covering at least the length of the predetermined code, wherein the first set of samples comprises at least one sample at each of the L discrete possible pulse positions;
• correlating the first set of samples with rotated versions of the predetermined code to obtain a first set of correlation values,
• comparing each correlation value in the set of correlation values with a noise threshold to determine if a signal is present;
• if a signal is not present, repeating the method with a new sampling delay;
• and
• if a signal is present, determining the actual pulse position and a code phase of the signal, wherein the code phase is a phase of the signal with respect to the predetermined code.