Patent ID: 6985538

Claim:
A base station apparatus, comprising: a transmitter that transmits transmission data to a terminal apparatus; and a modulator that modulates the transmitted transmission data with a modulation scheme corresponding to a propagation environment, said transmitted transmission data being modulated with a modulation scheme determined from at least two types of modulation schemes including a multi-level modulation scheme with a modulation level of at least 16 where amplitude is provided with information, said base station receiving, from the terminal apparatus, transmission data modulated with a modulation scheme corresponding to the propagation environment, the received transmission data being modulated with a modulation scheme determined from at least two types of phase modulation schemes, wherein each of a number of signal points of a symbol immediately before a pilot symbol and a number of signal points of another symbol immediately after the pilot symbol is at least two, and is less than the number of signal points of each of other information symbols, when said base station modulates the transmission data with the multi-level modulation scheme and transmits the data in a frame structure in which a pilot symbol comprising a single symbol is inserted in every three or more successive information symbols.