Wireless transmission device, wireless reception device, transmission method, and reception method

A reception device comprising:

• a receiver, which, in operation, receives a reference signal, which is generated by using a sequence having a sequence length according to a coefficient and is mapped to subcarriers at defined intervals having a length that is a reciprocal of the coefficient;
• and
• circuitry, which, in operation, performs channel estimation based on the received reference signal,
• wherein a value of the coefficient is same as a ratio of one subcarrier spacing among a plurality of subcarrier spacings to the maximum subcarrier spacing among the plurality of subcarrier spacings.