COOPERATIVE COMMUNICATION SYSTEM USING M-ARY DCM MODULATION BASED ON ORTHOGONAL FREQUENCY DIVISION??MULTIPLEXING AND METHOD THEREOF

摘要

PURPOSE: A cooperative communication system which uses an M-ary dual carrier modulation(DCM) process based on orthogonal frequency division multiplexing(OFDM) and a method thereof are provided to increase reliability without degradation of a transmission rate, thereby performing super-speed communications with high reliability using low power and costs. CONSTITUTION: An object terminal respectively calculates the distance between four candidate bit strings displayed in a constellation of a QPSK(Quadrature Phase Shift Keying) mapper and a first signal(S751). The object terminal respectively calculates the distance between the four candidate bit strings displayed in the constellation of the QPSK mapper and a second signal(S752). The object terminal respectively calculates the distance between sixteen candidate bit strings displayed in the constellation of a DCM(Dual Carrier Modulation) mapper and a third signal(S753). The object terminal respectively calculates the distance between the sixteen candidate bit strings displayed in the constellation of the DCM mapper and a fourth signal(S754). The object terminal adds each distance value corresponding to each of the sixteen candidate bit strings(S755). The object terminal estimates a candidate bit string which has a minimum distance sum as an original signal(S756).