| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a communication system between non-contact IC tags and reader/writers for more reducing interference between reader/writers than that in the existing communication system based on the frequency hopping system. <P>SOLUTION: Interference among the reader/writers is reduced by generating a frequency table for storing random frequency generating patterns in the predetermined time interval or as required with the means 19, 29 for generating, dividing and re-arranging the frequency table in the reader/writers 40, 50, and then storing this frequency table to the memories 30 and 31; and by hopping the frequency in accordance with such frequency table. Moreover, memory capacity required can be reduced and the time required for generation of the frequency table can be reduced by dividing a plurality of generated frequency tables into a plurality of sections, and by reducing the number of generations of frequency tables through use of such divided frequency tables by switching the tables in the desired sequence. <P>COPYRIGHT: (C)2007,JPO&INPIT |
