| 摘要 |
<P>PROBLEM TO BE SOLVED: To enable a receiver to perform error detection and error correction, by reducing the influence due to phase noise of a light source that becomes a problem, when increasing the number of signals in a multilevel optical phase modulation transmission. <P>SOLUTION: A transmitter 1 is provided with a phase encoding part 11 which divides an inputted binary data into by X-bit data, uniquely associates 2<SP>X</SP>-ary shown by the X-bit data with the (N/2-1)<SP>Y</SP>-ary signal of a Y symbol for conversion, and limits the use only for a signal point P1 (phase angle 0) and an N/2-2 pieces of signal points P (2n+2) (where 1≤n<N/2-2) among signal points of N value. A receiver 3 is provided with a phase-decoding part 32, which notifies error detection when receiving a signal other than the signal points allowed in use, and changes the signal points to a signal point closer to the Hamming distance to thereby correct the error. <P>COPYRIGHT: (C)2009,JPO&INPIT |
