System and method for tracking an ultrawide bandwidth signal

• US 7,508,865 B2
• Filed: 04/05/2005
• Issued: 03/24/2009
• Est. Priority Date: 05/26/2000
• Status: Expired due to Fees

• Current Assignee: North Star Innovations Inc. (Wi-LAN Inc.)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Rofheart, Martin, Miller, Timothy R.
• Primary Examiner(s): WANG, TED M
• Application Number:
  US11/098,419
• Publication Number:
  US 20050175076A1
• Time in Patent Office: 1,449 Days
• Field of Search: 375/150, 375/130, 375/136, 375/137, 375/147, 375/142, 375/295, 375/346, 375/143, 375/152, 375/343
• US Class Current: 375/150
• CPC Class Codes: G01S 13/0209 Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
• CPC Class Codes: G01S 7/023 Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile communication or other radar systems, e.g. using electro-magnetic interference [EMI] reduction techniques auxiliary means for detecting or identifying radar signals or the like G01S7/021; means for anti-jamming G01S7/36
• CPC Class Codes: H04B 1/71637 Receiver aspects H04B1/7183 takes precedence
• CPC Class Codes: H04B 1/7176 Data mapping, e.g. modulation
• CPC Class Codes: H04B 1/7183 Synchronisation
• CPC Class Codes: H04B 1/74 for increasing reliability, e.g. using redundant or spare channels or apparatus replacing by standby devices for amplifiers H03F1/52, H03F1/542
• CPC Class Codes: H04L 25/4902 Pulse width modulation; Pulse position modulation
• CPC Class Codes: H04L 27/0004 using wavelets

Abstract

A system and method for fast synchronization of an incoming signal with a UWB receiver. The present invention synchronizes a UWB receiver with an incoming signal. The present invention correlates a local pulse generated at the receiver with the incoming signal, finds the value in the correlation function that would correspond to a high signal to noise ratio, thereby matching the receiver to the incoming signal phase, and operates the receiver at that phase. Exemplary options of fast synchronization include a maximum peak detector.

Claims

1. A method for tracking an incoming ultra wide bandwidth signal at an ultra wide bandwidth receiver, comprising the steps of:

receiving incoming pulses of the incoming ultra wide bandwidth signal as a lead signal by a front end circuit;

delaying the incoming pulses by a set delay time to generate a lag signal;

determining an error signal based on the lead signal and the lag signal by an error determining circuit;

determining a sign of the error signal;

advancing a phase of a local clock if the sign has a first quality; and

retarding the phase of the local clock if the sign has a second quality,

wherein the incoming pulses are at least one of bi-phase modulated, and quadrature phase modulated,

wherein adjacent pulses of the incoming pulses arrive at a predetermined interval, the predetermined interval being the time between the incoming pulses, and

wherein the first quality is being one of positive or negative, and the second quality is being the inverse of the first quality.

2. The method for tracking an incoming ultra wide bandwidth signal, as recited in claim 1,

generating a difference signal based on a difference between the lead signal and the lag signal,

wherein the error signal is determined based on the difference signal, and

wherein the difference is calculated by one of:

subtracting the lead signal from the lag signal, subtracting the lag signal from the lead signal, subtracting an absolute value of the lead signal from an absolute value of the lag signal, and subtracting the absolute value of the lag signal from the absolute value of the lead signal.

3. The method for tracking an incoming ultra wide bandwidth signal, as recited in claim 2, further comprising:

generating local pulses to form a local signal; and

correlating the Local signal with the difference signal to produce a correlation function,

wherein the error signal is determined based on the correlation function.

4. The method for tracking an incoming ultra wide bandwidth signal, as recited in claim 1, further comprising:

generating local pulses to form a local signal; and

correlating the local signal with the lag signal to produce a first correlation function; and

correlating the local signal with the lag signal to produce a second correlation function,

wherein the error signal is determined by calculating a difference between the first correlation function and the second correlation function, and

wherein the difference is calculated by one of;

subtracting the lead signal from the lag signal, subtracting the lag signal from the lead signal, subtracting an absolute value of the lead signal from an absolute value of the lag signal, and subtracting the absolute value of the lag signal from the absolute value of the lead signal.

5. The method for tracking an incoming ultra wide bandwidth signal, as recited in claim 1, wherein the advancing or retarding of the phase of the local clock is done by a set phase adjustment value.

6. The method for tracking an incoming ultra wide bandwidth signal, as recited in claim 1, further comprising:

determining a magnitude of the error signal,

wherein the advancing or retarding of the phase of the local clack is done by a variable phase adjustment value that depends on the magnitude of the error signal.

7. The method for tracking an incoming ultra wide bandwidth signal, as recited in claim 6, further comprising:

determining whether the magnitude of the error signal is above a set threshold,

wherein the phase of the local clock is not advanced or retarded if the magnitude of the error signal is not above the set threshold.

8. A method for tracking an incoming ultra wide bandwidth signal at an ultra wide bandwidth receiver, comprising the steps of:

receiving incoming pulses of the incoming ultra wide bandwidth signal to farm a lead signal by a front end circuit;

delaying the incoming pulses by a first delay time to form an on-time signal;

delaying the incoming pulses by a second delay time to form a lag signal;

determining an error signal based on the lead signal, the on-time signal, and the lag signal by an error determining circuit;

generating a difference signal based on a difference between the lead signal and the lag signal;

determining an on-time sign of the on-time signal,

wherein the second delay time is greater than the first delay time,

wherein the incoming pulses are at least one of bi-phase modulated, and quadrature phase modulated,

wherein the error signal is determined based on the difference signal and the on-time sign, and

wherein the difference is calculated by one of;

subtracting the lead signal from the lag signal, and subtracting the lag signal from the lead signal.

9. The method for tracking an incoming ultra wide bandwidth signal, as recited in claim 8, wherein adjacent pulses of the incoming pulses arrive at a predetermined interval, the predetermined interval being the time between the incoming pulses.

10. The method for tracking an incoming ultra wide bandwidth signal, as recited in claim 8, further comprising:

determining an error sign of the error signal;

advancing a phase of a local clock if the error sign has a first value; and

retarding the phase of the local clock if the error sign has a second value.

11. The method for hacking an incoming ultra wide bandwidth signal, as recited in claim 10, wherein when the first value is positive the second value is negative, and when the first value is negative the second value is positive.

12. A system for tracking an incoming ultra wide bandwidth signal, comprising:

a front end circuit configured to receive incoming pulses of the ultra wide bandwidth signal as a lead signal;

a first delay for delaying the lead signal by a lag delay time to form a lag signal;

a summer for determining a difference signal equal to a difference between the lead signal and the lag signal;

a signal generator configured to generate local pulses as a local signal;

a correlator configured to correlate the difference signal with the local signal to produce an error signal; and

a control circuit to determine the sign of the error signal and to modify a phase of the local pulses based on the sign of the error signal.

13. The system for tracking an incoming ultra wide bandwidth signal, as recited in claim 12, wherein adjacent pulses of the incoming pulses arrive at a predetermined interval, the predetermined interval being the time between the incoming pulses.

14. The system for tracking an incoming ultra wide bandwidth signal, as recited in claim 12, wherein the control circuit is configured to advance the phase of the local pulses by a set phase adjustment value if the sign of the error signal has a first value, and to retard the phase the local pulses by the set phase adjustment value if the sign of the error signal has a second value.

15. The system for tracking an incoming ultra wide bandwidth signal, as recited in claim 12, wherein the control circuit further determines a magnitude of the error signal, and modifies the phase of the local pulses based on both the sign of the error signal and the magnitude of the error signal.

16. The system for tracking an incoming ultra wide bandwidth signal, as recited in claim 15,

wherein the control circuit is configured to advance the phase of the local pulses by a variable phase adjustment value if the sign of the error signal has a first value,

wherein the control circuit is configured to retard the phase the local pulses by the variable phase adjustment value if the sign of the error signal has a second value, and

wherein the variable phase adjustment value is determined by the magnitude of the error signal