Wireless communication system, wireless communication device, and wireless communication method

A communication method comprising:

• receiving control data including allocation information;
• transmitting a Discrete Fourier Transform-spread-OFDM (DFT-S-OFDM) signal;
• allocating the DFT-S-OFDM signal to a plurality of subcarriers based on the allocation information, wherein
• the allocation information indicates one of a first allocation method and a second allocation method,
• the first allocation method allocates the plurality of subcarriers continuously to form a single segment of subcarriers, and
• the second allocation method non-continuously allocates the plurality of subcarriers in at least a first segment and a second segment, the first segment including a first portion of the plurality of subcarriers continuously allocated to form the first segment, and the second segment including a second portion of the plurality of subcarriers continuously allocated to form the second segment;
• and
• determining a reduction amount by which to reduce a transmission power for transmitting the DFT-S-OFDM signal so that the reduction amount becomes smaller as a segment size is increased, wherein
• the segment size indicates a number of subcarriers included in each segment, and
• in a case that the segment size is a first segment size, determining the reduction amount comprises:
• calculating, for each of a plurality of segment sizes, an average value of the transmission power, thus obtaining a plurality of average values for the plurality of segment sizes including a first average value for the first segment size,
• determining a second segment size corresponding to a second average value that is maximum among the plurality of average values;
• and
• calculating, as the reduction amount, a difference between the first average value and the second average value.

A communication system which comprises:

• a first communication device;
• and
• a second communication device, wherein
• the first communication device comprises:
• reception circuitry configured to receive control data including allocation information;
• transmission circuitry configured to transmit a Discrete Fourier Transform-spread-OFDM (DFT-S-OFDM) signal;
• mapping circuitry configured to allocate the DFT-S-OFDM signal to a plurality of subcarriers based on the allocation information, wherein
• the allocation information indicates one of a first allocation method and a second allocation method,
• the first allocation method allocates the plurality of subcarriers continuously to form a single segment of subcarriers, and
• the second allocation method non-continuously allocates the plurality of subcarriers in at least a first segment and a second segment, the first segment including a first portion of the plurality of subcarriers continuously allocated to form the first segment, and the second segment including a second portion of the plurality of subcarriers continuously allocated to form the second segment;
• and
• control circuitry configured to determine a reduction amount by which to reduce a transmission power for transmitting the DFT-S-OFDM signal so that the reduction amount becomes smaller as a segment size is increased, wherein
• the segment size indicates a number of subcarriers included in each segment, and
• the control circuitry is configured to, in a case that the segment size is a first segment size, determine the reduction amount by:
• calculating, for each of a plurality of segment sizes, an average value of the transmission power, thus obtaining a plurality of average values for the plurality of segment sizes including a first value for the first segment size,
• determining a second segment size corresponding to a second average value that is maximum among the plurality of average values, and
• calculating, as the reduction amount, a difference between the first average value and the second average value.