Proximity integrated circuit card bias adjustment

A method for proximity integrated circuit card (PICC) bias adjustment, comprising:

• translating a data-frame signal having an information portion and a bias portion into an output code;
• adjusting the bias portion of the data-frame signal without adjusting the information portion of the data-frame signal such that the output code is within a decoding value range;
• and
• converting the output code into one of a first data-frame bit and a second data-frame bit, comprising defining a threshold, for translating the output code into either of the data-frame bits, which is equal to an average of a last received output code corresponding to the first data-frame bit and a last received output code corresponding to the second data-frame bit.

A system for bias adjustment between a proximity integrated circuit card (PICC) and a proximity coupling device (PCD), comprising:

• a decoding circuit, having an decoding value range, for translating a data-frame signal having a bias portion comprising an AC portion and an information portion comprising a DC portion into an output code;
• a bias adjust circuit coupled to receive the output code from the decoding circuit, and adjust the DC portion such that the output code is within the decoding value range, wherein the bias adjust circuit does not adjust the AC portion of the data-frame signal;
• and
• a logic circuit coupled to the decoding circuit and for converting the output code into one of a first data-frame bit and a second data-frame bit, wherein the logic circuit includes a threshold, for translating the output code into either of the data-frame bits, which is equal to an average of a last received output code corresponding to the first data-frame bit and a last received output code corresponding to the second data-frame bit.