| Popis: |
High-speed mobile wireless communication system always goes through the doubly selective wireless fading channels, which seriously affects the performance of communication systems. In this paper, a non-coherent chirp spread spectrum (CSS ) communication method is proposed based on CORDIC algorithm and differential frequency discriminator. According to the Doppler shift caused by constant and variable speed on the CSS communication method, an inner symbol differential decider is introduced to counteract the Doppler shift in highly dynamic scenes. In the situation of 4MHz carrier frequency and bit error rate less than 10 -4 , computer simulation shows that the proposed method based on CORDIC differential discriminator has a maximum resistance of Doppler shift up to about 150 kHz, which is much larger than the coherent method's 30Hz. |
