Research of bit errors, caused by Doppler effect

Digital data transmission plays a leading role for satellite systems today. Digital signals are very popular, because they allow transmit information more precisely and faster than analog signals. However, digital data transmission is possible with errors at demodulation, which cause distortion of transmitting information. Modern digital data transmission systems have to provide bit error ratio not less than 10-5. So special algorithms for processing signals and coding are often using today. Errors of digital data transmission are due to three causes. First cause is a low level of signal to noise ratio, when signal transmit through noisy or fading communication channel. Second cause is Doppler Effect. Third cause is symbol-to-symbol interference conditional multipath propagation. Space diversity reception is effective method of bit error resistance. Doppler Effect is the most significant for bit error probability at satellite communication. Because satellite move very fast in cosmic space. This article shows effective of space diversity reception for decrease of bit error probability, which caused by Doppler Effect.