SINGLE OR DUAL COMPLEX SUBCARRIER DOWNCONVERSION

• US 20120002762A1
• Filed: 06/21/2011
• Published: 01/05/2012
• Est. Priority Date: 07/01/2010
• Status: Active Grant

• Current Assignee: Zest Labs, Inc.
• Original Assignee: Intelleflex Corporation
• Inventors: Kawaguchi, Dean
• Granted Patent: US 9,361,488 B2
• Time in Patent Office: Days
• US Class Current: 375/343
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: H04Q 2213/13095 PIN / Access code, authentication

Abstract

A method for subcarrier downconversion and data detection according to one embodiment includes determining whether to use an upper sideband frequency section of a complex downconverter output, a lower sideband frequency section of the complex downconverter output, or both sideband frequency sections of the complex downconverter output; and processing the output corresponding to the selected sideband frequency section or sections based on the determination, wherein the processing includes correlation and data detection. Such methodology may also be implemented as a system using logic for performing the various operations. Additional systems and methods are also presented.

Claims

1. A method for subcarrier downconversion and data detection, the method comprising:

determining whether to use an upper sideband frequency section of a complex downconverter output, a lower sideband frequency section of the complex downconverter output, or both sideband frequency sections of the complex downconverter output; and

processing the output corresponding to the selected sideband frequency section or sections based on the determination, wherein the processing includes correlation and data detection.

2. The method of claim 1, wherein a determination to use the output of the upper sideband section or the lower sideband section is made to avoid interference.

3. The method of claim 1, wherein a determination to use the outputs of both the upper sideband section and the lower sideband section is made to improve the sensitivity.

4. The method of claim 1, wherein the determination is to use outputs of both sideband sections, wherein each sideband section includes a correlator, wherein the outputs of the correlators are combined after magnitude detection and before data slicing.

5. The method of claim 4, wherein each correlator includes a series of windowed integrators that are configurable for different lengths.

6. The method of claim 5, wherein each of the windowed integrators is a half symbol integrator correlator, wherein correlator variable delay modules provide a delay into two of the windowed integrators, wherein no delay is introduced into another two of the windowed integrators.

7. A system for subcarrier downconversion and data detection, the system comprising:

logic for determining whether to use an upper sideband frequency section of a complex downconverter output, a lower sideband frequency section of the complex downconverter output, or both sideband frequency sections of the complex downconverter output; and

logic for processing the output corresponding to the selected sideband frequency section or sections based on the determination, wherein the processing includes correlation and data detection.

8. The system of claim 7, wherein a determination to use the output of the upper sideband section or the lower sideband section is made to avoid interference.

9. The system of claim 7, wherein a determination to use the outputs of both the upper sideband section and the lower sideband section is made to improve the sensitivity of the system.

10. The system of claim 7, wherein each sideband section includes a correlator, wherein the outputs of the correlators are combined after magnitude detection and before data slicing when the determination is to use outputs of both sideband sections.

11. The system of claim 10, wherein each correlator includes a series of windowed integrators that are configurable for different lengths.

12. The system of claim 11, wherein each of the windowed integrators is a half symbol integrator correlator, wherein correlator variable delay modules provide a delay into two of the windowed integrators, wherein no delay is introduced into another two of the windowed integrators.

13. The system of claim 7, further comprising at least one antenna for receiving the radio frequency signal.