Digital mobile wireless communications apparatus and the system using the same

A digital-mobile-wireless-communications apparatus that moves at a velocity, the receiver of said apparatus comprising:

• a velocity-signal generator that converts information on an entered velocity into an electric signal to and outputs the electric signal as a velocity signal;
• a Doppler-frequency calculator that calculates a Doppler frequency based on the entered velocity and carrier frequencies used for said communications apparatus, and converts the calculated Doppler frequency into an electric signal and outputs the electric signal as a Doppler frequency signal;
• a receiving-electric-field-intensity-signal generator that calculates a receiving-electric-field intensity based on an entered receiving signal, and converts the signal into an electric signal and outputs the electric signal as a receiving-electric-field-intensity signal;
• transmission-environment-inference means that obtains information on a transmission environment by performing an evaluation based on the entered Doppler frequency signal and the receiving-electric-field-intensity signal, then converts the obtained information into an electric signal and outputs the electric signal as a transmission-environment-inference signal;
• and
• said transmission-environment inference means further for calculating a bit-error-rate associated with said communications signal based on said Doppler frequency signal and said receiving-electric-field-intensity signal.