The smart grid system is operating at discrete narrow-band frequency points of 230 MHz, which makes the scrambling method of PBCH more complex than LTE systems.The traditional procedure needs calculate more than one hundred thousand pseudo-random sequences,in which only a few thousand bits will be used for scrambling.A large amount of repetitive calculation weakens the real-time processing capability of the system.To solve this problem,an optimization algorithm of PBCH scrambling process based on look- up table is proposed,which generates a mapping table according to the scrambling law and replaces the calculation operation of the pseudo-random sequence by the array search operation. Then it simplifies the mechanism of frequency traversal. The simulation results show that the number of frequency traversal cycles is reduced from 480 to 8,and the efficiency of scrambling module is improved by approximately 8 times through the new optimization method,which effectively improves the real-time processing ability of the system.%智能电网无线通信系统使用230 MHz频段的离散窄带工作频点,这一特性使其PBCH信道加扰方式比普通LTE系统复杂.传统加扰方法每次要计算十几万比特的伪随机序列,但其中仅几千比特用于加扰,大量的重复计算增加了对SDR平台的实时信号处理压力.针对此问题,文中提出了一种基于查表法的PBCH信道加扰优化算法,根据加扰规律生成映射表,然后在加扰过程中用查找操作替代伪随机序列计算操作,并对频点遍历机制进行简化设计.仿真测量结果表明,对比传统加扰实现机制,频点遍历循环次数由480次减少到8次,加扰过程运行效率提升8倍,有效提高了系统的实时处理能力.
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