Transmission device, reception device, and base station

A transmission device included in one base station in a radio communication system including communication areas adjacent to each other in which the base station communicates with a plurality of wireless terminals, the transmission device comprising:

• modulation circuitry to generate a data symbol sequence;
• synchronization signal generating circuitry to generate a first symbol sequence constituted by two or more continuous repetitions of reference sequence symbols being a reference, generate a second symbol sequence by performing frequency shifting on the first symbol sequence by using a phase rotation sequence so that the reference sequence symbols become orthogonal for each of the wireless terminals, and generate a synchronization signal;
• and
• synchronization signal adding circuitry to generate a transmission signal by adding the synchronization signal to the data symbol sequence,
• wherein the phase rotation sequence is a first phase rotation sequence, and
• the synchronization signal generating circuitry performs frequency shifting on the second symbol sequence by using a second phase rotation sequence so that second symbol sequences to be repeatedly transmitted become orthogonal to each other to generate a third symbol sequence, and generate the synchronization signal.