Data carrier for transmitting data with different transmission parameters

1. A data carrier ( 1 ) for contactless communication with a communication station, the data carrier ( 1 ) comprising the means listed below:

reception means ( 3 ) for receiving an interrogation signal (IS), which interrogation signal (IS) can be generated by a communication station and can be transmitted to the data carrier ( 1 ) in a contactless manner by a field produced by the communication station and acting on the data carrier ( 1 ), and

generating means ( 17 ) for generating a response signal (RS) upon reception of the interrogation signal (IS) and

processing means ( 18 ) for processing the response signal (RS), the processing means ( 18 ) being designed to process the response signal (RS) into a transmission signal (MCRS; MCRS 1 , MCRS 2 , MCRS 3 ; MCRS 4 , MCRS 5 ) suitable for transmission to the communication station, in which processing means ( 18 ) at least one transmission parameter of the transmission signal (MCRS, MCRS 1 , MCRS 2 , MCRS 3 ; MCRS 4 , MCRS 5 ) can be varied, and

determination means ( 22 ) for determinating at least one representative value (REP 1 , REP 2 ), the representative value (REP 1 , REP 2 ) representing the field strength of the field acting on the data carrier ( 1 ), and

control connection means ( 25 ) between the determination means ( 22 ) and the processing means ( 18 ), the control connection means ( 25 ) being designed to controllably influence the processing means ( 18 ) as a function of the at least one representative value (REP 1 , REP 2 ), used to vary at least one transmission parameter of the transmission signal (MCRS; MCRS 1 , MCRS 2 , MCRS 3 ; MCRS 4 , MCRS 5 ) as a function of the at least one representative value (REP 1 , REP 2 ).

2. A data carrier ( 1 ) as claimed in claim 1 , wherein control means ( 26 ), which interact with the determination means ( 22 ), which are designed to generate control data (CDA) as a function of the at least one representative value (REP 1 , REP 2 ), and which interact with the processing means ( 18 ) in order to vary the at least one transmission parameter of the transmission signal (MCRS; MCRS 1 , MCRS 2 , MCRS 3 ; MCRS 4 , MCRS 5 ) by means of the control data generated, are provided in the control connection means ( 25 ).

3. A data carrier ( 1 ) as claimed in claim 1 , wherein the processing means ( 18 ) being designed for processing the response signal (RS) in at least two time windows beginning at different onset points, and wherein the processing means ( 18 ) for this purpose comprising time window defining means ( 19 ) capable of defining at least two different onset points for time windows as a function of the at least one representative value (REP 1 , REP 2 ).

4. A data carrier ( 1 ) as claimed in claim 1 , wherein the processing means ( 18 ) being designed for processing the response signal (RS) with at least two different methods of coding, and wherein the processing means ( 18 ) for this purpose comprising at least two coding stages ( 12 , 30 , 31 ) designed to perform different methods of coding, said coding stages being capable of performing at least two different methods of coding as a function of the at least one representative value (REP 1 , REP 2 ).

5. A data carrier ( 1 ) as claimed in claim 1 , wherein the processing means ( 18 ) being designed for processing the response signal (RS) with at least two different subcarrier signals (SCS 1 , SCS 2 ) capable of modulating the response signal (RS), and wherein the processing means ( 18 ) for this purpose comprising subcarrier signal generating means ( 32 ) capable of generating at least two different subcarrier signals (SCS 1 , SCS 2 ) as a function of the at least one representative value (REP 1 , REP 2 ).

6. A circuit ( 2 ) for a data carrier ( 1 ) for contactless communication with a communication station, the circuit ( 2 ) comprising the means listed below:

connection means ( 6 ) for receiving an interrogation signal (IS), which interrogation signal (IS) can be generated by a communication station and can be transmitted to the data carrier ( 1 ) and hence to the circuit ( 2 ) for the data carrier ( 1 ) in a contactless manner by a field produced by the communication station and acting on a data carrier ( 1 ), and

generating means ( 17 ) for generating a response signal (RS) upon reception of the interrogation signal (IS), and

processing means ( 18 ) for processing the response signal (RS), the processing means ( 18 ) being designed to process the response signal (RS) into a transmission signal (MCRS, MCRS 1 , MCRS 2 , MCRS 3 , MCRS 4 , MCRS 5 ) suitable for transmission to the communication station, in which processing means ( 18 ) at least one transmission parameter of the transmission signal (MCRS; MCRS 1 , MCRS 2 , MCRS 3 ; MCRS 4 , MCRS 5 ) can be varied, and

determination means ( 22 ) for determinating at least one representative value (REP 1 , REP 2 ), the representative value (REP 1 , REP 2 ) representing the field strength of the field acting on the data carrier ( 1 ), and

control connection means ( 25 ) between the determination means ( 22 ) and the processing means ( 18 ), the control connection means ( 25 ) being designed to controllably influence the processing means ( 18 ) as a function of the at least one representative value (REP 1 , REP 2 ), i.e. to vary at least one transmission parameter for the transmission signal (MCRS; MCRS 1 , MCRS 2 , MCRS 3 ; MCRS 4 , MCRS 5 ) as a function of the at least one representative value (REP 1 , REP 2 ).

7. A circuit ( 2 ) as claimed in claim 6 , wherein control means ( 26 ), which interact with the determination means ( 22 ), which are designed to generate control data (CDA) as a function of the at least one representative value (REP 1 , REP 2 ), and which interact with the processing means ( 18 ) in order to vary the at least one transmission parameter of the transmission signal (MCRS; MCRS 1 , MCRS 2 , MCRS 3 ; MCRS 4 , MCRS 5 ) by means of the control data generated, are provided in the control connection means ( 25 ).

8. A circuit ( 2 ) as claimed in claim 6 , wherein the processing means ( 18 ) being designed for processing the response signal (RS) in at least two time windows beginning at different onset points, and wherein the processing means ( 18 ) for this purpose comprising time window defining means ( 19 ) capable of defining at least two different onset points for time windows as a function of the at least one representative value (REP 1 , REP 2 ).

9. A circuit ( 2 ) as claimed in claim 6 , wherein the processing means ( 18 ) being designed for processing the response signal (RS) with at least two different methods of coding, and wherein the processing means ( 18 ) for this purpose comprising at least two coding stages ( 12 , 30 , 31 ) designed to perform different methods of coding, said coding stages being capable of performing at least two different methods of coding as a function of the at least one representative value (REP 1 , REP 2 ).

10. A circuit ( 2 ) as claimed in claim 6 , wherein the processing means ( 18 ) being designed for processing the response signal (RS) with at least two different subcarrier signals (SCS 1 , SCS 2 ) capable of modulating the response signal (RS), and wherein the processing means ( 18 ) for this purpose comprising subcarrier signal generating means ( 32 ) capable of generating at least two different subcarrier signals (SCS 1 , SCS 2 ) as a function of the at least one representative value (REP 1 , REP 2 ).

11. A communication station ( 40 ) for contactless communication with a data carrier ( 1 ), the data carrier ( 1 ) being designed for contactless communication with the communication station and comprising the following means: reception means ( 3 ) for receiving an interrogation signal (IS), which interrogation signal (IS) can be generated by the communication station and can be transmitted to the data carrier ( 1 ) in a contactless manner by a field produced by the communication station and acting on the data carrier ( 1 ), and generating means ( 17 ) for generating a response signal (RS) upon reception of the interrogation signal (IS) and processing means ( 18 ) for processing the response signal (RS) the processing means ( 18 ) being designed to process the response signal (RS) into a transmission signal suitable for transmission to the communication station(MCRS), in which processing means ( 18 ) at least one transmission parameter of the transmission signal (MCRS) can be varied, and determination means ( 22 ) for determinating at least one representative value (REP 1 , REP 2 ), the representative value (REP 1 , REP 2 ) representing the field strength of the field acting on the data carrier ( 1 ), and control connection means ( 25 ) between the determination means ( 22 ) and the processing means ( 18 ), the control connection means ( 25 ) being designed to controllably influence the processing means ( 18 ) as a function of the at least one representative value (REP 1 , REP 2 ), used to vary the at least one transmission parameter of the transmission signal (MCRS) as a function of the at least one representative value (REP 1 , REP 2 ), wherein the communication station ( 40 ) comprising the following means:

command signal generating means ( 43 ) for generating command signals (IS) and

reception means ( 49 ) for receiving the transmission signal (MCRS) transmitted from the data carrier ( 1 ) to the communication station ( 40 ), and

processing means ( 51 ) for processing the transmission signal received (MCRS), and

transmission parameter detection means ( 55 ) for detecting the transmission parameter of the transmission signal received (MCRS), and

decision means ( 57 ) which interact with the transmission parameter detection means ( 55 ) and which are intended and designed to decide on the generation of at least one command signal as a function of the transmission parameter of the received transmission signal (MCRS) detected by the transmission parameter detection means ( 55 ).

12. A communication station ( 40 ) as claimed in claim 11 , wherein the decision means ( 57 ) are provided between the transmission parameter detection means ( 55 ) and the command signal generating means ( 43 ) and are designed to influence the command signal generating means ( 43 ) as a function of the transmission parameter of the received transmission signal (MCRS) detected by the transmission parameter detection means ( 55 ), having regard to which command signals are allowed to be generated by the command signal generating means ( 43 ).