A method for detecting on-off keying symbols includes receiving, by each of distributed Rx nodes, a pilot signal for a pilot symbol transmitted from a transmitter, the distributed Rx nodes constituting the wireless body area communication network, obtaining, by each of the Rx nodes, a reference value using the received pilot signal, transmitting, by each of the Rx nodes, received data signal to a fusion center when the data signal for the on-off keying symbol transmitted from the transmitter is received by each of the Rx nodes, calculating, by the fusion center, a weight of the on-off keying symbol for each of the Rx nodes using the reference value obtained from each of the Rx nodes and the received data signal, and detecting, by the fusion center, the on-off keying symbol transmitted from the transmitter using the weight of the on-off keying symbol calculated for each of the Rx nodes.