Frequency bin method of initial carrier frequency acquisition

• US 6,801,567 B1
• Filed: 03/30/2000
• Issued: 10/05/2004
• Est. Priority Date: 03/30/2000
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Sriram, Sundararajan, Schmidl, Timothy M.
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): WANG, TED M
• Application Number:
  US09/539,040
• Time in Patent Office: 1,650 Days
• Field of Search: 375/147, 375/145, 375/350, 375/503, 375/149, 375/150, 375/342, 375/330, 375/340, 455/436, 455/510, 370/529, 370/333, 370/337, 714/755
• US Class Current: 375/149
• CPC Class Codes: H04B 1/70735 Code identification H04B1/7083 takes precedence
• CPC Class Codes: H04L 2027/0034 using hypothesis testing
• CPC Class Codes: H04L 2027/0065 Frequency error detectors H04L2027/0067 takes precedence
• CPC Class Codes: H04L 27/0014 Carrier regulation of chaotic carriers H04L27/001; for multicarrier receivers H04L27/2657

Abstract

A frequency bin method of carrier frequency acquisition uses a plurality of predetermined carrier frequency offset bins. A single bin is selected from among the plurality of bins. A local VCO is then adjusted to remove the carrier frequency offset associated with the single selected bin. Carrier frequency acquisition is then attempted using the adjusted VCO. If successful, the receiver enters its steady state operating mode. If unsuccessful, a new bin is selected and the VCO is again adjusted using the new carrier frequency offset associated with the newly selected bin. The process is repeated until successful communication is achieved in association with a properly adjusted VCO.

Claims

1. A method of carrier frequency acquisition for a WCDMA communication signal, the method comprising the steps of:

(a) establishing a plurality of carrier frequency offset bins, each bin within the plurality of bins having a uniquely distinct carrier frequency offset associated therewith;

(b) selecting a single bin from the plurality of carrier frequency offset bins;

(c) adjusting a voltage controlled oscillator to remove the uniquely distinct carrier frequency offset associated with the selected single bin;

(d) locating a primary synchronization code contained within a received WCDMA communication signal via a receiver associated with the adjusted voltage controlled oscillator;

(e) decoding a secondary synchronization code contained within the received WCDMA communication signal such that a code group comprising a set of scrambling codes associated with the received WCDMA communication signal can be determined, the secondary synchronization code overlapping a primary synchronization channel containing the primary synchronization code;

(f) correlating the set of scrambling codes with distinct pilot symbols contained within the received WCDMA communication signal to determine a scrambling code being used by a transmitter generating the scrambling code; and

(g) repeating steps (d)-(f) no longer than a predetermined maximum period of time to determine a valid scrambling code.

2. The method according to claim 1 further comprising the step of selecting a different single bin from the plurality of carrier frequency offset bins if a valid scrambling code has not been determined in step (g), wherein the different single bin is not associated with a most recently selected single bin, and repeating steps (c)-(g) following selection of the different single bin.

3. The method according to claim 2 further comprising the step of implementing a steady state operating mode associated with the receiver upon determination of the valid scrambling code.

4. The method according to claim 1 further comprising the step of implementing a steady state operating mode associated with the receiver upon determination of the valid scrambling code.

5. A method of carrier frequency acquisition for a WCDMA communication signal, the method comprising the steps of:

(a) establishing a plurality of carrier frequency offset bins, each bin within the plurality of bins having a uniquely distinct carrier frequency offset associated therewith, wherein one bin within the plurality of bins comprises a 0 Hz carrier frequency offset;

(b) selecting the bin comprising a 0 Hz carrier frequency offset;

(c) locating a primary synchronization code contained within a received WCDMA communication signal via a receiver having a voltage controlled oscillator adjusted to remove the distinct carrier frequency offset associated with the selected bin;

(d) decoding a secondary synchronization code contained within the received WCDMA communication signal such that a code group comprising a set of scrambling codes associated with the received WCDMA communication signal can be determined, the secondary synchronization code overlapping a primary synchronization channel containing the primary synchronization code;

(e) correlating the set of scrambling codes with distinct pilot symbols contained within the received WCDMA communication signal to determine a scrambling code being used by a transmitter generating the scrambling code; and

(f) repeating steps (c)-(e) no longer than a predetermined maximum period of time to determine a valid scrambling code.

6. The method according to claim 5 further comprising the step of selecting a different single bin from the plurality of carrier frequency offset bins if a valid scrambling code has not been determined in step (f), wherein the different single bin is not associated with a most recently selected single bin, and repeating steps (c)-(f) following selection of the different single bin.

7. The method according to claim 6 further comprising the step of implementing a steady state operating mode associated with the receiver upon determination of the valid scrambling code.

8. The method according to claim 5 further comprising the step of implementing a steady state operating mode associated with the receiver upon determination of the valid scrambling code.

9. A WCDMA communication system comprising:

at least one receiver configured to receive a WCDMA signal transmitted from a WCDMA transmitter, the at least one receiver comprising;

a data processor;

a data input device in communication with the data processor;

an algorithmic software directing the data processor; and

a data storage unit, wherein discrete frequency bin data, discrete WCDMA radio frame data, discrete WCDMA time slot data, discrete WCDMA primary synchronization channel data, discrete WCDMA secondary synchronization channel data and discrete pilot symbol data is stored and supplied to the data processor such that the data processor, directed by the algorithmic software, can automatically determine valid scrambling code data associated with a transmitter generating a WCDMA communication signal, using algorithmically defined relationships associated with the discrete frequency bin data, discrete radio frame data, discrete time slot data, discrete primary synchronization channel data, discrete secondary synchronization channel data and discrete pilot symbol data.

10. The WCDMA communication system according to claim 9 further comprising an adjustable voltage controlled oscillator (VCO) in electrical communication with the data processor such that the data processor, directed by the algorithmic software, is capable of controlling adjustment of the VCO to remove a carrier frequency offset associated with a single frequency offset bin selected from a plurality of predetermined frequency offset bins.

14. The WCDMA communication system according to claim 9 wherein the algorithmic software is configured to select a single carrier frequency offset bin from a plurality of predetermined carrier frequency offset bins after the predetermined period of time has elapsed, wherein the selected single carrier frequency offset bin is not associated with a most recently selected single carrier frequency offset bin.

11. A WCDMA communication system comprising:

at least one receiver configured to receive a WCDMA signal transmitted from a WCDMA transmitter, the at least one receiver comprising;

a data processor;

a data in input device in communication with the data processor;

an algorithmic software directing the data processor;

a data storage unit, wherein discrete frequency bin data, discrete WCDMA radio frame data, discrete WCDMA time slot data, discrete WCDMA primary synchronization channel data, discrete WCDMA secondary synchronization channel data and discrete pilot symbol data is stored and supplied to the data processor such that the data processor, directed by the algorithmic software, can automatically determine valid scrambling code data associated with a transmitter generating a WCDMA communication signal, using algorithmically defined relationships associated with the discrete frequency bin data, discrete radio frame data, discrete time slot data, discrete primary synchronization channel data, discrete secondary synchronization channel data and discrete pilot symbol data; and

a timer configured to stop correlating the set of scrambling codes with distinct pilot symbols after a predetermined period of time has elapsed.

12. The WCDMA communication system according to claim 11 wherein the timer is a hardware device.

13. The WCDMA communication system according to claim 11 wherein the timer comprises a portion of the algorithmic software.

15. A method of carrier frequency acquisition for a WCDMA communication signal, the method comprising the steps of:

(a) locating a primary synchronization code contained within a received WCDMA communication signal via a receiver having a voltage controlled oscillator (VCO) adjusted to remove a distinct carrier frequency offset selected from among a plurality of predetermined carrier frequency offsets;

(b) decoding a secondary synchronization code contained within the received WCDMA communication signal such that a code group comprising a set of scrambling codes associated with the received WCDMA communication signal can be determined, the secondary synchronization code overlapping a primary synchronization channel containing the primary synchronization code;

(c) correlating the set of scrambling codes with distinct pilot symbols contained within the received WCDMA communication signal to determine a scrambling code being used by a transmitter generating the scrambling code; and

(d) repeating steps (a)-(c) if a valid scrambling code cannot be determined within a predetermined maximum period of time.

16. The-method according to claim 15 further comprising the step of establishing a plurality of carrier frequency offset bins, each carrier frequency offset bin within the plurality of carrier frequency offset bins having a uniquely distinct carrier frequency offset associated therewith to establish the plurality of predetermined carrier frequency offsets.

17. A method of carrier frequency acquisition for a WCDMA communication signal, the method comprising the steps of:

(a) establishing a plurality of carrier frequency offset bins, each carrier frequency offset bin within the plurality of carrier frequency offset bins having a uniquely distinct carrier frequency offset associated therewith to establish the plurality of predetermined carrier frequency offsets;

(b) locating a primary synchronization code contained within a received WCDMA communication signal via a receiver having a voltage controlled oscillator (VCO) adjusted to remove a distinct carrier frequency offset selected- from among a plurality of predetermined carrier frequency offsets;

(c) decoding a secondary synchronization code contained within the received WCDMA communication signal such that a code group comprising a set of scrambling codes associated with the received WCDMA communication signal can be determined, the secondary synchronization code overlapping a primary synchronization channel containing the primary synchronization code;

(d) correlating the set of scrambling codes with distinct pilot symbols contained within the received WCDMA communication signal to determine a scrambling code being used by a transmitter generating the scrambling code;

(e) repeating steps (b)-(d) if a valid scrambling code cannot be determined within a predetermined maximum period of time; and

(f) wherein the step of locating a primary synchronization code in step (b) is initiated by selecting a carrier frequency offset bin comprising a 0 Hz carrier frequency offset such that the VCO need not be adjusted before initially commencing steps (c)-(e) a first time.

18. A method of carrier frequency acquisition for a WCDMA communication signals the method comprising the steps of:

(a) configuring a plurality of carrier frequency offset bins such that a plurality of predetermined carrier frequency offsets are sufficient in combination to substantially eliminate temperature dependent frequency errors associated with a voltage controlled oscillator (VCO), each carrier frequency offset bin within the plurality of carrier frequency offset bins having a uniquely distinct carrier frequency offset associated therewith to establish the plurality of predetermined carrier frequency offsets;

(b) locating a primary synchronization code contained within a received WCDMA communication signal via a receiver having said VCO adjusted to remove a distinct carrier frequency offset selected from among a plurality of predetermined carrier frequency offsets;

(c) decoding a secondary synchronization code contained within the received WCDMA communication signal such that a code group comprising a set of scrambling codes associated with the received WCDMA communication signal can be determined, the secondary synchronization code overlapping a primary synchronization channel containing the primary synchronization code;

(d) correlating the set of scrambling codes with distinct pilot symbols contained within the received WCDMA communication signal to determine a scrambling code being used by a transmitter generating the scrambling code; and

(e) repeating steps (b)-(d) if a valid scrambling code cannot be determined within a predetermined maximum period of time.

19. A method of carrier frequency acquisition for a WCDMA communication signal, the method comprising the steps of:

(a) locating a primary synchronization code contained within a received WCDMA communication signal via a receiver having a voltage controlled oscillator (VCO) adjusted to remove a distinct carrier frequency offset selected from among a plurality of predetermined carrier frequency offsets;

(b) decoding a secondary synchronization code contained within the received WCDMA communication signal such that a code group comprising a set of scrambling codes associated with the received WCDMA communication signal can be determined, the secondary synchronization code overlapping a primary synchronization channel containing the primary synchronization code;

(c) correlating the set of scrambling codes with distinct pilot symbols contained within the received WCDMA communication signal to determine a scrambling code being used by a transmitter generating the scrambling code;

(d) implementing a steady state operating mode associated with a receiver receiving the WCDMA communication signal upon determination of the valid scrambling code; and

(e) repeating steps (a)-(d) if a valid scrambling code cannot be determined within a predetermined maximum period of time.

20. A method of carrier frequency acquisition for a communication signal, the method comprising the steps of:

(a) performing a carrier frequency offset correction within a communications receiver to remove a first predetermined carrier frequency offset;

(b) performing synchronization procedures within a communications receiver to synchronize communications between a transmitter and a receiver performing the carrier frequency offset correction of step (a); and

(c) repeating steps (a) and (b) using a newly predetermined carrier frequency offset if synchronization is not completed within a maximum period of time, wherein the newly predetermined carrier frequency offset is not associated with a most recently predetermined carrier frequency offset.

21. The method according to claim 20 wherein the step (a) of performing a carrier frequency offset correction comprises performing a carrier frequency offset correction associated with a WCDMA communications signal.

22. The method according to claim 20 wherein the step (a) of performing a carrier frequency offset correction comprises performing a carrier frequency offset correction associated with a communications signal having pilot symbols.

23. The method according to claim 20 wherein the step (b) of performing synchronization procedures comprises adjusting a voltage controlled oscillator (VCO) to remove a most recently predetermined carrier frequency offset.

24. A method of carrier frequency acquisition for a communication signal, the method comprising the steps of:

(a) performing a carrier frequency offset correction within a communications receiver to remove a first predetermined carrier frequency offset;

(b) performing synchronization procedures within a communications receiver, comprising multiplying a communications signal by complex frequency correction factors to remove a most recently predetermined carrier frequency offset, to synchronize communications between a transmitter and a receiver performing the carrier frequency offset correction of step (a); and

(c) repeating steps (a) and (b) using a newly predetermined carrier frequency offset if synchronization is not completed within a maximum period of time, wherein the newly predetermined carrier frequency offset is not associated with a most recently predetermined carrier frequency offset.