Apparatus for the transmission and reception of data and method for digital radio communication

Frame configuration determination section 101 judges a communication situation based on the transmission path information indicating the level of fluctuations of the transmission path due to fading and data transmission speed information indicating the transmission speed of the transmission data based on the level of the reception signal and determines the interval of inserting a known pilot symbol and the modulation system of a transmission digital signal. Quadrature baseband modulation section 102 modulates the transmission digital signal to a quadrature baseband signal according to the modulation system indicated from frame configuration determination section 101. Pilot symbol generation section 103 generates a pilot symbol known between the transmitting and receiving sides. Frame configuration section 104 inserts the known pilot symbol output from pilot symbol generation section 103 at the insertion interval instructed from frame configuration determination section 101 to configure a frame. This makes it possible to flexibly improve the data transmission efficiency and the quality of data at the same time.