DIFFERENTIAL DECODER FOR ORTHOGONAL AMPLITUDE MODULATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a differential decoder simple in circuit configuration and capable of reducing the memory capacity of a lookup table. SOLUTION: This differential decoder 10 is provided with a differential decoder 20 that applies differential decoding two bits in received n-bit data, a rotation device 30 that rotates the other (n-2) bits of data in n-bit received in the 1st quadrant based on the 2-bit of the n-bit data received by the differential decoder 20, and a single quadrant de-mapping circuit 40 that assigns the amplitude of the received signal to a value of data bits based on the data in (n-2) bits rotated by the rotation device 30. Then an output signal in 2-bit is obtained from the differential decoder 20 and data in (n-2) bits of the output signal are obtained from the single quadrant demapping circuit 40.