Data carrier provided with at least two decoding stages

Abstract

In a data carrier ( 1 ) which includes receiving means ( 5 ) for receiving a modulated carrier signal (MTS) which contains a data signal (DS 1 ) encoded in conformity with an encoding method (MA, PW, MI, RTZ, FSK, PSK), demodulation means ( 9 ) for demodulating the received modulated carrier signal (MTS) and for outputting the encoded data signal (DS 1 ) contained therein, decoding means ( 10, 20 ) for decoding the encoded data signal (DS 1 ) and for outputting data (D 1 , D 2 ), and data processing means ( 11 ) for processing the data (D 1 , D 2 ) output by the decoding means ( 10, 20 ), the decoding means ( 10, 20 ) are provided with at least a first decoding stage ( 12 ) and a second decoding stage ( 13 ), the first decoding stage ( 12 ) being arranged to decode a data signal (DS 1 ) encoded in conformity with a first method (RTZ) whereas the second decoding stage ( 13 ) is arranged to decode a data signal (DS 1 ) encoded in conformity with a second method (MI).

1 . A data carrier device comprising:
 a receiving device configured to receive a modulated carrier signal, the modulated carrier signal includes an encoded data signal;   a demodulation device configured to demodulate the received modulated carrier signal and outputs the included encoded data signal; and   a decoding device configured decode the encoded data signal and outputting data, said decoding device including at least a first decoding stage and a second decoding stage, the first decoding stage is arranged to decode said data signal in conformity with a first decoding method whereas the second decoding stage is arranged to decode said data signal in conformity with a second decoding method.   
     
     
         2 . The data carrier device of  claim 1 , further including a decision stage which determines which of the first and second decoding stages is suitable to decode the encoded data signal. 
     
     
         3 . The data carrier device of  claim 2 , further including a data processing device configured to process the data output by the decoding device. 
     
     
         4 . The data carrier device of  claim 3 , wherein once the decision stage applies decision information to the data processing device regarding which of the first and second decoding stages decodes the encoded data signal, the determined first or second decoding stage is used for processing the remainder of the encoded data signal. 
     
     
         5 . The data carrier device of  claim 1 , wherein the first decoding method is Manchester and the second decoding method is Miller. 
     
     
         6 . The data carrier device of  claim 1 , wherein said encoded data signal has a structure that ensures that time intervals with high amplitude value of the modulated carrier signal are substantially at least as long as time intervals with low amplitude value of the modulated carrier signal. 
     
     
         7 . The data carrier device of  claim 1 , wherein in the first decoding stage is implemented in software. 
     
     
         8 . The data carrier device of  claim 1 , wherein the second decoding stage is implemented in software. 
     
     
         9 . The data carrier device of  claim 1 , wherein in the first decoding stage is implemented in hardware. 
     
     
         10 . The data carrier device of  claim 1 , wherein the second decoding stage is implemented in hardware.