提出了一种基于离散短时傅里叶变换的逐码滑动差分四相相移键控(differential quadrature phase-shift keying,DQPSK)信号解调算法:首先利用数字测频完成位同步;再利用离散短时傅里叶变换(discrete short time Fourier transform...提出了一种基于离散短时傅里叶变换的逐码滑动差分四相相移键控(differential quadrature phase-shift keying,DQPSK)信号解调算法:首先利用数字测频完成位同步;再利用离散短时傅里叶变换(discrete short time Fourier transform,DSTFT)后的频域相位信息,完成对信号的差分解调。详细阐述了算法的解调原理和过程,分析了对遥测信号解调的适用情况,给出了对比仿真结果。该算法解调性能良好,运行效率高,便于软件化实时处理。展开更多
Optimization of mapping rule of bit-interleaved Turbo coded modulation with 16 quadrature amplitude modulation (QAM) is investigated based on different impacts of various encoded bits sequence on Turbo decoding perfor...Optimization of mapping rule of bit-interleaved Turbo coded modulation with 16 quadrature amplitude modulation (QAM) is investigated based on different impacts of various encoded bits sequence on Turbo decoding performance. Furthermore, bit-interleaved in-phase and quadrature phase (I-Q) Turbo coded modulation scheme are designed similarly with I-Q trellis coded modulation (TCM). Through performance evaluation and analysis, it can be seen that the novel mapping rule outperforms traditional one and the I-Q Turbo coded modulation can not achieve good performance as expected. Therefore, there is not obvious advantage in using I-Q method in bit-interleaved Turbo coded modulation.展开更多
文摘提出了一种基于离散短时傅里叶变换的逐码滑动差分四相相移键控(differential quadrature phase-shift keying,DQPSK)信号解调算法:首先利用数字测频完成位同步;再利用离散短时傅里叶变换(discrete short time Fourier transform,DSTFT)后的频域相位信息,完成对信号的差分解调。详细阐述了算法的解调原理和过程,分析了对遥测信号解调的适用情况,给出了对比仿真结果。该算法解调性能良好,运行效率高,便于软件化实时处理。
文摘Optimization of mapping rule of bit-interleaved Turbo coded modulation with 16 quadrature amplitude modulation (QAM) is investigated based on different impacts of various encoded bits sequence on Turbo decoding performance. Furthermore, bit-interleaved in-phase and quadrature phase (I-Q) Turbo coded modulation scheme are designed similarly with I-Q trellis coded modulation (TCM). Through performance evaluation and analysis, it can be seen that the novel mapping rule outperforms traditional one and the I-Q Turbo coded modulation can not achieve good performance as expected. Therefore, there is not obvious advantage in using I-Q method in bit-interleaved Turbo coded modulation.