Claims for Patent: 9,787,511

Summary for Patent: 9,787,511

Title:	Methods, devices and systems for receiving and decoding a signal in the presence of noise using slices and warping
Abstract:	A method may comprise receiving and sampling a signal. The signal may encode a data packet. A slice may be generated and stored comprising a pair of values for each of a selected number of samples of the signal representing a correlation of the signal to reference functions in the receiver. The presence of the data packet may then be detected and the detected packet decoded from the stored slices. The generating and storing slices may be carried out as the received signal is sampled. The sampled values of the signal may be discarded as the slices are generated and stored. The slice representation of the signal can be manipulated to generate filters with flexible bandwidth and center frequency.
Inventor(s):	Fleming; Robert (Nicasio, CA), Kushner; Cherie (Nicasio, CA), McAllister; William H. (Saratoga, CA), Zdeblick; Mark (Portola Valley, CA)
Assignee:	PROTEUS DIGITAL HEALTH, INC. (Redwood City, CA)
Application Number:	14/989,409
Patent Claims:	1. A method implemented by a receiver, the method comprising: receiving a signal, by an analog front-end of the receiver, the signal encoding a data packet at a first frequency; sampling the signal, by an analog-to-digital converter (ADC) of the receiver to generate sampled values; correlating, by a controller of the receiver, the sampled values with first and second templates of values obtained at a second frequency that is different from the first frequency to generate a plurality of slices at the second frequency, each of the slices comprising a pair of values; transforming, by the controller, at least some of the plurality of slices at the second frequency to slices at the second frequency plus or minus an offset, and generating, by the controller, a filter having a center frequency at the second frequency plus or minus the offset by combining the transformed slices. 2. The method of claim 1, further comprising determining whether the first frequency is within a pass-band of the generated filter. 3. The method of claim 2, further comprising iteratively transforming, generating and determining using respectively different offsets until the first frequency is within the passband of the filter. 4. The method of claim 1, further comprising discarding the sampled values of the received signal. 5. The method of claim 1, further comprising storing and indexing the generated plurality of slices in a memory. 6. A receiver, comprising: an analog-to-digital converter (ADC) configured to generate sampled values from a received signal at a first frequency, wherein an analog front-end of the receiver receives the received signal; a memory; a controller coupled to the memory and configured to: correlate the sampled values over respective selected numbers of the sampled values of with first and second templates of values obtained at a second frequency that is different from the first frequency to generate a plurality of slices that each comprise a pair of values; transform at least some of the plurality of slices at the second frequency to slices at the second frequency plus or minus an offset, and generate a filter having a center frequency at the second frequency plus or minus the offset by combining the transformed slice. 7. The receiver of claim 6, wherein the controller is further configured to store and index the slices in the memory. 8. The receiver of claim 6, further comprising discarding the sampled values of the received signal. 9. The receiver of claim 6, wherein the controller is further configured to determine whether the first frequency is within a pass-band of the generated filter. 10. The receiver of claim 9, wherein the receiver is further configured to iteratively transform, generate and determine using respectively different offsets until the first frequency is within the pass-band of the filter. 11. A method implemented by a receiver, the method, comprising: receiving a signal, by an analog front-end of the receiver, the signal encoding a data packet; sampling the signal, by an analog-to-digital converter (ADC) of the receiver to generate sampled values; generating, by a controller of the receiver, a slice record comprising a plurality of slices by correlating the sampled values with first and second reference templates, the first reference template comprising a first reference function and the second reference template comprising a second reference function in quadrature with the first reference function; auto-correlating, by the controller, a portion of the slice record with a delayed version of the portion of the slice record to generate auto-correlation terms; and determining, by the controller, when magnitudes of auto-correlation terms exceed a predetermined threshold for a predetermined number of auto-correlation terms. 12. The method of claim 11, wherein the predetermined threshold is a predetermined noise threshold. 13. The method of claim 11, wherein the predetermined number of correlation terms is associated with an expected width of at least a preamble of the data packet. 14. The method of claim 11, wherein the first reference function comprises a cosine function and wherein the second reference function comprises a sine function. 15. The method of claim 11, further comprising determining a carrier frequency of the received signal. 16. The method of claim 15, wherein determining comprises: warping at least some of the plurality of slices by a frequency offset, and generating a filter from the warped slices, and determining whether the carrier frequency is within a passband of the generated filter. 17. The method of claim 16, wherein warping and generating comprise shifting a center frequency of the generated filter without re-acquiring or re-sampling the signal. 18. The method of claim 11, further comprising discarding the sampled values of the received signal after generating the slice record.