Methods for fast and low-power UWB IR baseband receiver synchronization
First Claim
Patent Images
1. A method, comprising:
- receiving a predetermined code phase from a course synchronization stage;
receiving a signal comprising at least one pulse and a plurality of pulse frames, wherein each pulse frame comprises a number L of discrete possible pulse positions and the at least one pulse is located at an actual pulse position within the plurality of pulse frames;
applying a varying sampling delay to repeatedly sample the signal to obtain a number N of samples, wherein N is less than or equal to L, and wherein the number N of samples includes at least one sample at each of the L discrete possible pulse positions;
correlating the number N of samples with at least one rotated version of a predetermined code to determine a plurality of correlations, wherein the at least one rotated version is selected from a plurality of predetermined limited rotated versions based on the predetermined code phase, and wherein the plurality of predetermined limited rotated versions include fewer than all possible rotated versions; and
based on the correlations, 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.
1 Assignment
0 Petitions
Accused Products
Abstract
The invention relates to methods for synchronizing a device to a signal containing a train of pulses representing a programmable number of repetitions of a predetermined code. Pulse position and code phase are searched for. In a first aspect, a programmable number of samples is taken per pulse frame in function of the available number of repetitions of said predetermined code. In a second aspect, the method comprises a signal detection stage from which, after performing a confirmation stage, information can be kept for a subsequent stage. In a third aspect, only a limited number of rotated versions of the predetermined code are checked, using a presumed code phase which is kept from a preceding stage.
6 Citations
18 Claims
-
1. A method, comprising:
-
receiving a predetermined code phase from a course synchronization stage; receiving a signal comprising at least one pulse and a plurality of pulse frames, wherein each pulse frame comprises a number L of discrete possible pulse positions and the at least one pulse is located at an actual pulse position within the plurality of pulse frames; applying a varying sampling delay to repeatedly sample the signal to obtain a number N of samples, wherein N is less than or equal to L, and wherein the number N of samples includes at least one sample at each of the L discrete possible pulse positions; correlating the number N of samples with at least one rotated version of a predetermined code to determine a plurality of correlations, wherein the at least one rotated version is selected from a plurality of predetermined limited rotated versions based on the predetermined code phase, and wherein the plurality of predetermined limited rotated versions include fewer than all possible rotated versions; and based on the correlations, 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. 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. - View Dependent Claims (11, 12, 13, 14, 15)
-
-
16. 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.
-
-
17. 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. - View Dependent Claims (18)
-
Specification