A reception device which receives a plurality of radio signals transmitted from a transmission device which is provided with either one or a plurality of antenna elements by means of a plurality of antenna elements, comprising: a first orthogonal conversion unit which performs orthogonal conversion on N number, wherein N > 1, of time series data extracted from the radio signals received by the respective antenna elements; a detection unit which extracts transmitted signals from the respective antenna elements of the transmission devices from N number of signals which have been orthogonally converted by the first orthogonal conversion unit; an inverse orthogonal conversion unit which performs inverse orthogonal conversion on the transmitted signals extracted by the detection unit; and a rectangular filter unit which removes Mh number of time series data in the front end portion and Mt number of time series data in the rear end portion from the transmitted signals which have undergone inverse orthogonal conversion by the inverse orthogonal conversion unit, so as to extract Nw number, wherein Nw = N - Mh - Mt ≧ 1, of time series data, characterized in that: after the first orthogonal conversion unit has extracted N number of time series data starting from an A th radio signal received by the respective antenna elements, the first orthogonal conversion unit extracts N number of time series data starting from the (A + Nw) th radio signal; and a plurality of the Nw number of time series data output from the rectangular filter unit are connected in time series sequence so as to be used as the transmitted signals a first orthogonal conversion unit which performs orthogonal conversion on N number, wherein N > 1, of time series data extracted from the radio signals received by the respective antenna elements; a detection unit which extracts transmitted signals from the respective antenna elements of the transmission devices from N number of signals which have been orthogonally converted by the first orthogonal conversion unit; an inverse orthogonal conversion unit which performs inverse orthogonal conversion on the transmitted signals extracted by the detection unit; and a rectangular filter unit which removes Mh number of time series data in the front end portion and Mt number of time series data in the rear end portion from the transmitted signals which have undergone inverse orthogonal conversion by the inverse orthogonal conversion unit, so as to extract Nw number, wherein Nw = N - Mh - Mt ≧ 1, of time series data, characterized in that: after the first orthogonal conversion unit has extracted N number of time series data starting from an A th radio signal received by the respective antenna elements, the first orthogonal conversion unit extracts N number of time series data starting from the (A + Nw) th radio signal; and a plurality of the Nw number of time series data output from the rectangular filter unit are connected in time series sequence so as to be used as the transmitted signals after the first orthogonal conversion unit has extracted N number of time series data starting from an A th radio signal received by the respective antenna elements, the first orthogonal conversion unit extracts N number of time series data starting from the (A + Nw) th radio signal; and a plurality of the Nw number of time series data output from the rectangular filter unit are connected in time series sequence so as to be used as the transmitted signals