Patent ID: 7869342

Claim:
A transmission device comprising: a serial-parallel conversion portion that serial-parallel converts a transmission signal to a plurality of signals corresponding to Nc number of subcarriers and outputs the plurality of signals, the i-th symbol in the time direction of the n-th signal in the plurality of signals being: d(n,i); a frequency symbol diffusion portion that outputs a plurality of signals with substantially the same transmitting electrical power with respect to the output plurality of signals d(n,i) for each signal group, in which each Nsf signals in order of n of the plurality of signals d(n,i) is grouped, using a plurality of complex orthogonal diffusion series c 0 (0),c 0 (1), . . . ,c 0 (Nsf−1), c 1 (0),c 1 (1), . . . ,c 1 (Nsf−1), . . . c Nsf−1 (0),c Nsf−1 (0), . . . ,c Nsf−1 (Nsf−1), with a length of Nsf with respect to said outputted plurality of signals d(n,i), wherein | c k ( m )|=1 and if k=w, Σ m=0 Nsf−1 c k ( m )· c w ( m )*= Nsf; if k≠w, Σ m=0 Nsf−1 c k ( m )· c w ( m )*=0 and an expression (·)* acquires complex conjugation and floor (·) conducts truncation, among the plurality of signals, the i-th symbol in the time direction of the n-th signal is: u ( n,i )=Σ k=0 Nsf−1 c k ( n mod Nsf )· d (floor( n/Nsf )· Nsf+k,i ); a pseudo random-number multiplication portion that multiplies each of said outputted plurality of signals u(n,i) by a pseudo random-number code series c PN (n) out of the pseudo random-number code series c PN (0),c PN (1), . . . and outputs the result; an inverse Fourier transform portion that conducts inverse Fourier transform of said outputted plurality of signals c PN (n)·u(n,i) and outputs a plurality of signals; a parallel-serial conversion portion that parallel-serial converts said plurality of signals outputted after the inverse Fourier transform; and a transmission portion that transmits the signal of the result of said parallel-serial converted signal; and an adaptive modulating portion that adaptive modulates the transmission signal on the basis of feedback information for each signal group transmitted from a receiving device.