TRANSMITTER, TRANSMISSION METHOD, COMMUNICATION SYSTEM AND COMMUNICATION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a transmitter and a communication system which transmit plural transmitting signals on different transmitting beams interfering with each other, receive separately the transmitting signals at the receiving side and estimate the original transmitting signals by the maximum likelihood estimation method and according to correlation of receiving signals. SOLUTION: The encoding means of a transmitter encodes the transmitting signals to generate at least two transmitting signals S1 and S2 and modulates the signals S1 and S2 into the carrier frequencies to supply them with weighting to an antenna element. Then, the modulated output signals are transmitted by the beams overlapping spatially and partially each other and via control of the weight. A receiver receives separately the transmitting signals via an antenna adaptive to a transmission line, receives at least two receiving signals RS1 and RS2 and estimates the original transmitting signals by a maximum likelihood estimation method, e.g. the Viterbi decoding algorithm and according to correlation of receiving signals. Thus, the error rates of decoded signals are reduced and the communication quality can be improved.