In this article, we give the construction of new four-dimensional signal constellations in the Euclidean space, which represent a certain combination of binary frequency-shift keying (BFSK) and <i>M</i>-ar...In this article, we give the construction of new four-dimensional signal constellations in the Euclidean space, which represent a certain combination of binary frequency-shift keying (BFSK) and <i>M</i>-ary amplitude-phase-shift keying (MAPSK). Description of such signals and the formulas for calculating the minimum squared Euclidean distance are presented. We have developed an analytic building method for even and odd values of <i>M</i>. Hence, no computer search and no heuristic methods are required. The new optimized BFSK-MAPSK (<i>M </i>= 5,6,···,16) signal constructions are built for the values of modulation indexes <i>h</i> =0.1,0.15,···,0.5 and their parameters are given. The results of computer simulations are also provided. Based on the obtained results we can conclude, that BFSK-MAPSK systems outperform similar four-dimensional systems both in terms of minimum squared Euclidean distance and simulated symbol error rate.展开更多
An efficient way of noise reduction has been presented: A modified Costas loop called as Masterpiece. The basic version of the Costas loop has been developed for SSB SC demodulation, but the same circuit can be applie...An efficient way of noise reduction has been presented: A modified Costas loop called as Masterpiece. The basic version of the Costas loop has been developed for SSB SC demodulation, but the same circuit can be applied for QAM (quadrature amplitude modulation) demodulation as well. Noise sensitivity of the basic version has been decreased. One trick is the transformation of the real channel input into complex signal, the other one is the application of our folding algorithm. The result is that the Masterpiece provides a 4QAM symbol error rate (SER) of 6 × 10<sup><span style="white-space:nowrap;">−</span>4</sup> for input signal to noise ratio (SNR) of <span style="white-space:nowrap;">−</span>1 dB. In this paper, an improved version of the original Masterpiece is introduced. The complex channel input signal is normalized, and rotational average is applied. The 4QAM result is SER of 3 × 10<sup><span style="white-space:nowrap;">−</span>4</sup> for SNR of <span style="white-space:nowrap;">−</span>1 dB. At SNR of 0 dB, the improved version produces 100 times better SER than that the original Costas loop does. In our times, this topic has a special importance because by application of our Masterpiece, all dangerous field strengths from 5G and WiFi, could be decreased by orders of magnitude. The Masterpiece can break the Shannon formula.展开更多
针对高动态场景下多普勒频移问题和缺少定量分析,该文以研究正交调制的多普勒频移响应机理为基点,对多普勒频移对正交调制系统的影响进行了研究,从星座图判决区间的角度推导了多进制数字相位调制信号和多进制正交幅度调制信号在多普勒...针对高动态场景下多普勒频移问题和缺少定量分析,该文以研究正交调制的多普勒频移响应机理为基点,对多普勒频移对正交调制系统的影响进行了研究,从星座图判决区间的角度推导了多进制数字相位调制信号和多进制正交幅度调制信号在多普勒频移下的误符号率公式。理论分析和实验结果表明:多普勒频移对正交调制的影响是星座的旋转,误符号率公式推导结果与实际误符号率基本相同,系统的性能随着调制指数和运动速度的增加而下降。在信噪比为20 d B时,多进制数字相位调制信号的抗多普勒频移能力要强于多进制正交幅度调制信号。展开更多
为解决无人机协作通信中的数据时延问题,将复数域网络编码(complex field network coding, CFNC)引入到协作通信中。针对无人机工作时视距与非视距2种典型场景,提出2种适用于无人机网络的部分连通拓扑结构。将CFNC应用到上述无人机网络...为解决无人机协作通信中的数据时延问题,将复数域网络编码(complex field network coding, CFNC)引入到协作通信中。针对无人机工作时视距与非视距2种典型场景,提出2种适用于无人机网络的部分连通拓扑结构。将CFNC应用到上述无人机网络中,推导基于CFNC的信息传递方案,理论分析结果表明该方案可大幅度提高数据吞吐量性能。最后将CFNC与"RA+BPSK"无人机数据链信号传输体制相结合。基于MATLAB软件的仿真结果表明:CFNC中继方式可以充分获得空间分集增益,相同参数的RA+BPSK+CFNC信号在所提结构中的误符号率明显优于全联通结构。展开更多
文摘In this article, we give the construction of new four-dimensional signal constellations in the Euclidean space, which represent a certain combination of binary frequency-shift keying (BFSK) and <i>M</i>-ary amplitude-phase-shift keying (MAPSK). Description of such signals and the formulas for calculating the minimum squared Euclidean distance are presented. We have developed an analytic building method for even and odd values of <i>M</i>. Hence, no computer search and no heuristic methods are required. The new optimized BFSK-MAPSK (<i>M </i>= 5,6,···,16) signal constructions are built for the values of modulation indexes <i>h</i> =0.1,0.15,···,0.5 and their parameters are given. The results of computer simulations are also provided. Based on the obtained results we can conclude, that BFSK-MAPSK systems outperform similar four-dimensional systems both in terms of minimum squared Euclidean distance and simulated symbol error rate.
文摘An efficient way of noise reduction has been presented: A modified Costas loop called as Masterpiece. The basic version of the Costas loop has been developed for SSB SC demodulation, but the same circuit can be applied for QAM (quadrature amplitude modulation) demodulation as well. Noise sensitivity of the basic version has been decreased. One trick is the transformation of the real channel input into complex signal, the other one is the application of our folding algorithm. The result is that the Masterpiece provides a 4QAM symbol error rate (SER) of 6 × 10<sup><span style="white-space:nowrap;">−</span>4</sup> for input signal to noise ratio (SNR) of <span style="white-space:nowrap;">−</span>1 dB. In this paper, an improved version of the original Masterpiece is introduced. The complex channel input signal is normalized, and rotational average is applied. The 4QAM result is SER of 3 × 10<sup><span style="white-space:nowrap;">−</span>4</sup> for SNR of <span style="white-space:nowrap;">−</span>1 dB. At SNR of 0 dB, the improved version produces 100 times better SER than that the original Costas loop does. In our times, this topic has a special importance because by application of our Masterpiece, all dangerous field strengths from 5G and WiFi, could be decreased by orders of magnitude. The Masterpiece can break the Shannon formula.
文摘针对高动态场景下多普勒频移问题和缺少定量分析,该文以研究正交调制的多普勒频移响应机理为基点,对多普勒频移对正交调制系统的影响进行了研究,从星座图判决区间的角度推导了多进制数字相位调制信号和多进制正交幅度调制信号在多普勒频移下的误符号率公式。理论分析和实验结果表明:多普勒频移对正交调制的影响是星座的旋转,误符号率公式推导结果与实际误符号率基本相同,系统的性能随着调制指数和运动速度的增加而下降。在信噪比为20 d B时,多进制数字相位调制信号的抗多普勒频移能力要强于多进制正交幅度调制信号。
文摘为解决无人机协作通信中的数据时延问题,将复数域网络编码(complex field network coding, CFNC)引入到协作通信中。针对无人机工作时视距与非视距2种典型场景,提出2种适用于无人机网络的部分连通拓扑结构。将CFNC应用到上述无人机网络中,推导基于CFNC的信息传递方案,理论分析结果表明该方案可大幅度提高数据吞吐量性能。最后将CFNC与"RA+BPSK"无人机数据链信号传输体制相结合。基于MATLAB软件的仿真结果表明:CFNC中继方式可以充分获得空间分集增益,相同参数的RA+BPSK+CFNC信号在所提结构中的误符号率明显优于全联通结构。