新一代卫星电视标准中解调算法的研究

通过分析8PSK调制方式的载波恢复、定时恢复算法,提出了一种适用于新一代数字卫星电视
标准DVB-S2的全数字解调算法,改进了相位频率检测（PFD）算法以适合于8PSK解调。载波恢复采用频率
检测（FD）和相位频率检测相结合的结构,跟踪范围超过1倍符号率。采用Gardner TED算法进行定时恢复
。通过分析及计算机定点仿真,确定了解调系统中各环路的最优参数,并给出在AWGN信道条件下的误符号
率曲线。仿真结果表明,提出的解调结构性能接近于理论值,且在该解调系统中所采用的算法均易于硬件
实现。

Demodulator algorithm for new generation satellite broadcast standard

Through analyzing the 8PSK demodulation algorithm including carrier recovery and clock timing recovery, an all-digital 8PSK demodulator suitable to the next generation digital satellite television standard DVB-S2 was proposed. The carrier recovery algorithm consists of a frequency detector (FD) loop and a modified phase-frequency detector (PFD) loop. Its tracking range exceeds one time symbol-rate. The Gardner TED algorithm was used in the clock timing recovery loop. Results of analysis and computer fixed point simulation were applied to determine the optimal parameter of each loop. The symbol error performance under AWGN was also presented. Simulation result shows that the demodulator's performance is close to theory and realizable, and all algorithms can be implemented in hardware.