Method for coding a sequence of data bits, in particular for transmission via an air interface

A mobile data memory for non-contacting interchange of a sequence of data bits with a reader/writer, said data memory comprising:

• a first coding device;
• a sequence of data bits, the first coding device operable to assist in coding the sequence of data bits, at least one of said data bits having a logical on value or a logical off value, said at least one of said data bits being organized in a sequence of time slot frames, at least one of the time slot frames having a plurality of time slots,
• wherein each of said plurality of times slots is capable of having an on value or an off value, said at least one time slot frame further including:
• at least one time slot preloaded with the off value to form a preloaded time slot,
• at least one time slot with the off value following a time slot with the on value, and
• each of the time slots other than the preloaded time slot loaded with the on value or the off va1ue to form the logical on value or the logical off value for the at least one of said data bits,
• wherein the logical on value is complementary to the logical off value.

A reader/writer for non-contacting interchange of a sequence of data bits with at least one mobile data memory comprising:

• a second coding device operable to assist in coding the sequence of data bits, at least one of said data bits having a logical on value or a logical off value, said at least one of said data bits being organized in a sequence of time slot frames, at least one of the time slot frames having a plurality of time slots, each of said plurality of times slots capable of having an on value or an off value;
• wherein the second coding device is operable to assist in preloading at least one predetermined time slot with the off value to form a preloaded time slot, and
• at least one time slot with the off value always follows a time slot with the on value, and
• each of the time slots other than the preloaded time slot are loaded with the on value or the off value to form the logical on value or the logical off value for the at least one of said data bits,
• wherein the logical on value is complementary to the logical off value.

An identification system comprising:

• a mobile data memory for non-contacting interchange of a sequence of data bits with a reader/writer, said data memory having a first coding device and a sequence of data bits;
• a reader/writer having a second coding device;
• the first coding device and the second coding device operable to assist in coding the sequence of data bits, at least one of said data bits having a logical on value or a logical off value, said sequence of data bits being organized in a sequence of time slot frames, at least one of the time slot frames having a plurality of time slots, each of said plurality of times slots capable of having an on value or an off value, said sequence of data bits further including:
• at least one time slot preloaded with the off value to form a preloaded time slot,
• at least one time slot with the off value always following a time slot with the on value, and
• each of the time slots other than the preloaded time slot loaded with the on value or the off va1ue to form the logical on value or the logical off value for the at least one of said data bits,
• wherein the logical on value is complementary to the logical off value.

A method for coding a sequence of data bits to detect a collision between a first data source and a second data source, said method comprising:

• representing at least one of said data bits from the first data source using a first sequence of time slots, each time slot from said first sequence of time slots having an on value or an off value;
• and
• representing a corresponding data bit from the second data source using a second sequence of time slots, each time slot from said second sequence of time slots having the on value or the off value;
• preloading a predetermined time slot from the first and second sequence of time slots with the off value;
• performing a logical operation combining the at least one of said data bits from the first data source and the second data source;
• detecting the collision based on a result of the logical operation, and
• replacing the predetermined time slot with the on value if the collision is detected.