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一、方案概述AMT-871采用多音并发的短波数传体制,使高速数据流以较低的速率分配到各个子信道上,这样可以用较长的码元时间加上一定的时护时间,减少短波信道中多径引起的码间干扰的影响,由于 TDPSK 调制方式抗多径干扰能力强,对帧同步的精度要求不高,虽受相位抖动影响较大,但考虑到在低信噪比时帧同步的准确度问题,AMT-871采用了对帧同步误差不敏感的 TDPSK 调制方式。用(24,12)格雷码提供了前向纠错。为了最大限度地减少
First, the program overview AMT-871 multi-tone concurrent shortwave data transfer system, so that high-speed data streams at a lower rate assigned to each sub-channel, so you can use a longer symbol time plus a certain time, Due to the strong anti-multipath interference ability of the TDPSK modulation method and less requirement on the accuracy of the frame synchronization, the influence of the phase jitter is great. However, in consideration of the low signal-to-noise ratio Time frame synchronization accuracy issues, AMT-871 uses a frame synchronization error insensitive TDPSK modulation. Forward error correction is provided with (24, 12) Gray code. In order to minimize