An OAM multiplexing communication system configured to use a plurality of orbital angular momentum, OAM, modes and multiplex signals of the plurality of OAM modes, characterized in that the OAM multiplexing communication system comprises: a transmitting station including: a transmitting antenna including a multi-uniform circular array, M-UCA, in which a plurality of uniform circular arrays, UCAs, having different diameters are concentrically disposed, each UCA having a plurality of antenna elements disposed circularly at an equal interval; and an OAM mode generation unit that is configured to simultaneously generate the plurality of OAM modes from each UCA of the transmitting antenna; and a receiving station including: a receiving antenna including a configuration equivalent to the M-UCA; an OAM mode separation unit that is configured to separate signals received by each UCA of the receiving antenna for each of the plurality of OAM modes; and a channel estimation and interference compensation unit that is configured to estimate a channel matrix for the plurality of OAM modes, each OAM mode separated from the signals received by the each UCA of the receiving antenna, and compensate for inter-mode interference between the plurality of OAM modes by using weights calculated from the channel matrix, wherein the OAM modes are consecutively numbered and the channel estimation and interference compensation unit is configured to select, for each OAM mode, signals of a subject mode and a mode with a number adjacent to the number of the subject mode from among the signals of the OAM modes separated by the OAM mode separation unit, and to compensate for the inter-mode interference by multiplying an approximated weight calculated by using channel matrixes of the subject mode and the mode with the number adjacent to the number of the subject mode. a transmitting station including: a transmitting antenna including a multi-uniform circular array, M-UCA, in which a plurality of uniform circular arrays, UCAs, having different diameters are concentrically disposed, each UCA having a plurality of antenna elements disposed circularly at an equal interval; and an OAM mode generation unit that is configured to simultaneously generate the plurality of OAM modes from each UCA of the transmitting antenna; and a transmitting antenna including a multi-uniform circular array, M-UCA, in which a plurality of uniform circular arrays, UCAs, having different diameters are concentrically disposed, each UCA having a plurality of antenna elements disposed circularly at an equal interval; and an OAM mode generation unit that is configured to simultaneously generate the plurality of OAM modes from each UCA of the transmitting antenna; and a receiving station including: a receiving antenna including a configuration equivalent to the M-UCA; an OAM mode separation unit that is configured to separate signals received by each UCA of the receiving antenna for each of the plurality of OAM modes; and a channel estimation and interference compensation unit that is configured to estimate a channel matrix for the plurality of OAM modes, each OAM mode separated from the signals received by the each UCA of the receiving antenna, and compensate for inter-mode interference between the plurality of OAM modes by using weights calculated from the channel matrix, wherein a receiving antenna including a configuration equivalent to the M-UCA; an OAM mode separation unit that is configured to separate signals received by each UCA of the receiving antenna for each of the plurality of OAM modes; and a channel estimation and interference compensation unit that is configured to estimate a channel matrix for the plurality of OAM modes, each OAM mode separated from the signals received by the each UCA of the receiving antenna, and compensate for inter-mode interference between the plurality of OAM modes by using weights calculated from the channel matrix, wherein the OAM modes are consecutively numbered and the channel estimation and interference compensation unit is configured to select, for each OAM mode, signals of a subject mode and a mode with a number adjacent to the number of the subject mode from among the signals of the OAM modes separated by the OAM mode separation unit, and to compensate for the inter-mode interference by multiplying an approximated weight calculated by using channel matrixes of the subject mode and the mode with the number adjacent to the number of the subject mode.