【摘要】 针对恶劣信道条件下最小汉明距算法判决效果较差的特点,提出了一种改进算法,与4QAM解映射相结合,应用于DTMB系统的NR解码模块。仿真结果表明,改良后的算法令系统性能提高了近1.5dB;另外,利用NR码字特点,硬件设计中采用对称实现,节约了近一半ROM;定系数乘法器采用CSD编码技术,以节省硬件资源。更多还原

【Abstract】 As the least Han-Ming distance algorithm does not work well in atrocious channel,a modified arithmetic was proposed,in combination with 4-QAM demapping method,for Nordstrom Robinson (NR) decoder module based on National DTMB Standard.Simulation results indicated that the system performance was improved by about 1.5 dB,compared with the former design.On account of NR code traits,symmetric design was employed,which cut down almost half of ROMs.And CSD code was used for constant coefficient multiplier to save hardware resource.更多还原