Method and apparatus for distributed processing for wireless sensors

• US 10,045,293 B2
• Filed: 10/07/2016
• Issued: 08/07/2018
• Est. Priority Date: 12/03/2009
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Garudadri, Harinath, Baheti, Pawan Kumar, Majumdar, Somdeb
• Primary Examiner(s): Mesfin, Yemane
• Assistant Examiner(s): DAVENPORT, MON CHERI S
• Application Number:
  US15/288,809
• Publication Number:
  US 20170099634A1
• Time in Patent Office: 669 Days
• Field of Search: 370252, 370254, 370350, 370428, 370503-514
• CPC Class Codes: A61B 2560/0209 adapted for power saving
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/002 Monitoring the patient using a local or closed circuit, e.g. in a room or building A61B5/0017 takes precedence
• CPC Class Codes: A61B 5/0024 for multiple sensor units attached to the patient, e.g. using a body or personal area network
• CPC Class Codes: A61B 5/7232 involving compression of the physiological signal, e.g. to extend the signal recording period
• CPC Class Codes: G01D 21/00 Measuring or testing not otherwise provided for
• CPC Class Codes: G16H 40/63 for local operation
• CPC Class Codes: H04J 3/0658 Clock or time synchronisation among packet nodes
• CPC Class Codes: H04W 4/70 Services for machine-to-machine communication [M2M] or machine type communication [MTC]
• CPC Class Codes: H04W 52/0209 in terminal devices terminal devices per se H04W88/02

Abstract

Certain aspects of the present disclosure relate to a method for compressed sensing (CS). The CS is a signal processing concept wherein significantly fewer sensor measurements than that suggested by Shannon/Nyquist sampling theorem can be used to recover signals with arbitrarily fine resolution. In this disclosure, the CS framework is applied for sensor signal processing in order to support low power robust sensors and reliable communication in Body Area Networks (BANs) for healthcare and fitness applications.

Claims

1. A method of processing data, the method comprising:

maintaining, at a first apparatus, a first clock signal, wherein the first apparatus comprises a gateway of a body area network (BAN);

transmitting, from the first apparatus, a clock synchronization signal for synchronizing a second clock signal, at a second apparatus, to the first clock signal, wherein the second apparatus comprises a sensor in the BAN;

receiving, at the first apparatus, one or more packets comprising a first set of samples indicative of an input over a period of time, the first set of samples corresponding to the second clock signal, and wherein samples in the first set of samples are spaced at non-uniform time-instances over the period of time; and

generating, at the first apparatus, a second set of samples representing the signal over the period of time based, at least in part, on the first set of samples, wherein the second set of samples corresponds to the first clock signal, and wherein samples in the second set of samples are spaced at uniform time instances over the period of time.

2. The method of claim 1, wherein the first set of samples comprises k+δ

samples, wherein k is a target number of samples and δ

is a number of additional or absent samples.

3. The method of claim 2, further comprising:

determining a mismatch amount to which the first and second clock signals are not synchronized, wherein in the number of additional or absent samples is based, at least in part, on the mismatch amount; and

comparing the mismatch amount to a threshold, wherein;

the clock synchronization signal is transmitted when the mismatch amount the amount exceeds the threshold.

4. The method of claim 1, wherein the clock synchronization signal is transmitted periodically or aperiodically.

5. The method of claim 1, wherein:

the first set of samples comprises n samples, wherein n is less than a number of samples corresponding to Nyquist rate sampling the signal over the period of time; and

the second set of samples comprises n samples, wherein n is greater than or equal to a number of samples corresponding to Nyquist rate sampling the signal over the period of time.

6. The method of claim 1, further comprising:

receiving a third set of samples, wherein the third set of samples corresponds to a third clock signal, wherein the third set of samples represents a second signal over the period of time, and wherein samples in the third set of samples are spaced at non-uniform time instances over the period of time; and

generating a fourth set of samples representing the second signal over the period of time based, at least in part, on the third set of samples, the fourth set of samples corresponding to the second clock signal, and wherein samples in the fourth set of samples are spaced at uniform time instances over the period of time.

7. A gateway of a body area network (BAN), comprising:

means for maintaining a first clock signal;

means for transmitting a clock synchronization signal for synchronizing a second clock signal, at a sensor in the BAN, to the first clock signal;

means for receiving one or more packets comprising a first set of samples indicative of an input over a period of time, the first set of samples corresponding to the second clock signal, and wherein samples in the first set of samples are spaced at non-uniform time-instances over the period of time; and

means for generating, at the gateway of the BAN, a second set of samples representing the signal over the period of time based, at least in part, on the first set of samples, wherein the second set of samples corresponds to the first clock signal, and wherein samples in the second set of samples are spaced at uniform time instances over the period of time.

8. The gateway of claim 7, wherein the first set of samples comprises k+δ

samples, wherein k is a target number of samples and δ

is a number of additional or absent samples.

9. The gateway of claim 8, further comprising:

means for determining a mismatch amount to which the first and second clock signals are not synchronized, wherein in the number of additional or absent samples is based, at least in part, on the mismatch amount; and

means for comparing the mismatch amount to a threshold, wherein;

the clock synchronization signal is transmitted when the mismatch amount the amount exceeds the threshold.

10. The gateway of claim 7, wherein the clock synchronization signal is transmitted periodically or aperiodically.

11. The gateway of claim 7, wherein:

the first set of samples comprises n samples, wherein n is less than a number of samples corresponding to Nyquist rate sampling the signal over the period of time; and

the second set of samples comprises n samples, wherein n is greater than or equal to a number of samples corresponding to Nyquist rate sampling the signal over the period of time.

12. The gateway of claim 7, further comprising:

means for receiving a third set of samples, wherein the third set of samples corresponds to a third clock signal, wherein the third set of samples represents a second signal over the period of time, and wherein samples in the third set of samples are spaced at non-uniform time instances over the period of time; and

means for generating a fourth set of samples representing the second signal over the period of time based, at least in part, on the third set of samples, the fourth set of samples corresponding to the second clock signal, and wherein samples in the fourth set of samples are spaced at uniform time instances over the period of time.

13. A gateway of a body area network (BAN), comprising:

at least one processor coupled with a memory and configured to maintain a first clock signal;

a transmitter configured to transmit a clock synchronization signal for synchronizing a second clock signal, at a sensor in the BAN, to the first clock signal; and

a receiver configured to receive one or more packets comprising a first set of samples indicative of an input over a period of time, the first set of samples corresponding to the second clock signal, wherein;

samples in the first set of samples are spaced at non-uniform time-instances over the period of time;

the at least one processor is further configured to generate a second set of samples representing the signal over the period of time based, at least in part, on the first set of samples;

the second set of samples corresponds to the first clock signal; and

samples in the second set of samples are spaced at uniform time instances over the period of time.

14. The gateway of claim 13, wherein the first set of samples comprises k+δ

samples, wherein k is a target number of samples and δ

is a number of additional or absent samples.

15. The gateway of claim 14, wherein:

the at least one processor is further configured to;

determine a mismatch amount to which the first and second clock signals are not synchronized, wherein in the number of additional or absent samples is based, at least in part, on the mismatch amount; and

compare the mismatch amount to a threshold; and

the transmitter is configured to transmit the clock synchronization signal when the mismatch amount the amount exceeds the threshold.

16. The gateway of claim 13, wherein transmitter is configured to transmit the clock synchronization signal periodically or aperiodically.

17. The gateway of claim 13, wherein:

the first set of samples comprises n samples, wherein n is less than a number of samples corresponding to Nyquist rate sampling the signal over the period of time; and

the second set of samples comprises n samples, wherein n is greater than or equal to a number of samples corresponding to Nyquist rate sampling the signal over the period of time.

18. The gateway of claim 13, wherein:

the receiver is further configured to receive a third set of samples, the third set of samples corresponding to a third clock signal, the third set of samples representing a second signal over the period of time, and the third set of samples being spaced at non-uniform time instances over the period of time; and

the at least one processor is further configured to generate a fourth set of samples representing the second signal over the period of time based, at least in part, on the third set of samples, the fourth set of samples corresponding to the second clock signal, and samples in the fourth set of samples being spaced at uniform time instances over the period of time.