Method for wireless data transmission

• US 20050210360A1
• Filed: 03/16/2005
• Published: 09/22/2005
• Est. Priority Date: 03/16/2004
• Status: Active Grant

• Current Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Original Assignee: Atmel Automotive GmbH (Microchip Technology Incorporated)
• Inventors: Friedrich, Ulrich
• Granted Patent: US 7,613,987 B2
• Time in Patent Office: Days
• US Class Current: 714/758
• 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: G06K 7/10059 transponder driven

Abstract

A method for wireless data transmission between a base station and one or more, in particular passive, transponders is provided, in which electromagnetic carrier waves are emitted by the base station. Data comprising successive characters are transmitted from a respective transponder to the base station by modulation and backscattering of the electromagnetic carrier waves, and a respective one of the characters is coded and transmitted by a respective transponder within a predefined time interval. Within at least one of the predefined time intervals, a safeguard character formed from the data to be transmitted is transmitted in addition to the character to be transmitted.

Claims

1. A method for wireless data transmission between a base station and one or more transponders, the method comprising the steps of:

emitting electromagnetic carrier waves by the base station;

transmitting data comprising successive characters from a respective transponder by modulation and backscattering of the electromagnetic carrier waves; and

coding and transmitting a respective one of the characters by the respective transponder within a predefined time interval;

wherein, within at least one of the predefined time intervals, a safeguard character formed from the data to be transmitted is transmitted in addition to the character to be transmitted.

2. The method according to claim 1, wherein the modulation of the transmitted data is a PSK modulation or a ASK modulation.

3. The method according to claim 1, wherein the coding is a 3phase1 coding, an FM0 coding, or an NRZI coding.

4. The method according claim 1, wherein the predefined time interval is predefined by the base station by successive synchronization marks.

5. The method according to claim 4, wherein the successive synchronization marks are generated by field gaps or by a phase reversal of the electromagnetic carrier wave.

6. The method according to claim 1, wherein the safeguard character is part of a cyclic redundancy code formed from the data.

7. The method according to claim 1, wherein the safeguard character is a parity bit.

8. The method according to claim 1, wherein the safeguard character is coded by an additional modulation state that does not code a character.

9. The method according to claim 8, wherein the additional modulation state is generated by driving a varactor in an input circuit of the transponder.

10. The method according to claim 1, wherein the safeguard character is transmitted within the predefined time interval after the character that is to be transmitted.

11. The method according to claim 1, wherein the characters are part of an identification bit sequence which is transmitted from a transponder to the base station during a transponder selection method.

12. The method according to claim 1, wherein the transponder is a passive transponder.

13. The method according to claim 1, wherein the transponder transmits the data comprising successive characters to the base station or another base station.

14. A method for wireless transmission between a base and at least one transponder, the method comprising the steps of:

determining a coding type;

forming a safeguard character from payload data; and

selecting a predefined time interval for transmitting the safeguard data and the payload data based upon the determination of the coding type.

15. A wireless transponder, comprising:

an execution unit;

a memory functionally coupled to the execution unit, containing instructions causing the processor to determine a coding type, form a safeguard character from payload data, and select a predefined time interval for transmitting the safeguard data and the payload data; and

a multiplexer functionally coupled to the execution unit, which combines payload data and safeguard data based upon intervals determined by the execution unit.