Patent ID: 8116398

Claim:
A transmitter for transmitting signals via at least a first antenna and a second antenna, comprising: a first sequence generating unit configured to generate a first sequence for estimating a first channel condition, the first sequence being same as a sequence obtained by performing a first cyclic shift on a CAZAC sequence, and the first cyclic shift being a first amount set for the transmitter; a second sequence generating unit configured to generate a second sequence for estimating a second channel condition, the second sequence being same as a sequence obtained by performing a second cyclic shift on the CAZAC sequence, and the second cyclic shift being a second amount set for the transmitter and different from the first amount; a first block signal generating unit configured to generate a first block signal, the first block signal being same as a signal obtained by performing a third cyclic shift on a block signal generated from data, and the third cyclic shift being a third amount; and a second block signal generating unit configured to generate a second block signal, the second block signal being same as a signal obtained by performing a fourth cyclic shift on the block signal generated from the data, and the fourth cyclic shift being a fourth amount different from the third amount, wherein a period in which the first sequence and the second sequence are transmitted differs from a period in which the first block signal and the second block signal are transmitted, a frequency with which the first block signal and the second block signal are transmitted is set for the transmitter, the first amount and the second amount are set for the transmitter, a gap between the first amount and the second amount differs from a gap between the third amount and the fourth amount, the first sequence and the first block signal are transmitted at least via the first antenna, and the second sequence and the second block signal are transmitted at least via the second antenna.