Djordjevic Goran T, Milic Dejan N, Vasic Bata, Makal Jarosław, Vasic Bane
Faculty of Electronic Engineering, University of Nis, 18104 Nis, Serbia.
Faculty of Electrical Engineering, Białystok University of Technology, 15-351 Białystok, Poland.
Entropy (Basel). 2023 Sep 15;25(9):1341. doi: 10.3390/e25091341.
We examine the effects of imperfect phase estimation of a reference signal on the bit error rate and mutual information over a communication channel influenced by fading and thermal noise. The Two-Wave Diffuse-Power (TWDP) model is utilized for statistical characterization of propagation environment where there are two dominant line-of-sight components together with diffuse ones. We derive novel analytical expression of the Fourier series for probability density function arising from the composite received signal phase. Further, the expression for the bit error rate is presented and numerically evaluated. We develop efficient analytical, numerical and simulation methods for estimating the value of the error floor and identifying the range of acceptable signal-to-noise ratio (SNR) values in cases when the floor is present during the detection of multilevel phase-shift keying (PSK) signals. In addition, we use Monte Carlo simulations in order to evaluate the mutual information for modulation orders two, four and eight, and identify its dependence on receiver hardware imperfections under the given channel conditions. Our results expose direct correspondence between bit error rate and mutual information value on one side, and the parameters of TWDP channel, SNR and phase noise standard deviation on the other side. The results illustrate that the error floor values are strongly influenced by the phase noise when signals propagate over a TWDP channel. In addition, the phase noise considerably affects the mutual information.
我们研究了参考信号相位估计不完善对受衰落和热噪声影响的通信信道上误码率和互信息的影响。两波扩散功率（TWDP）模型用于对传播环境进行统计表征，该环境中有两个主要的视距分量以及散射分量。我们推导了由复合接收信号相位产生的概率密度函数的傅里叶级数的新颖解析表达式。此外，给出了误码率的表达式并进行了数值评估。我们开发了高效的分析、数值和仿真方法，用于估计误码平台的值，并在检测多级相移键控（PSK）信号时存在误码平台的情况下，确定可接受的信噪比（SNR）值范围。此外，我们使用蒙特卡罗模拟来评估调制阶数为二、四和八时的互信息，并在给定信道条件下确定其对接收机硬件不完善的依赖性。我们的结果揭示了一方面误码率与互信息值之间的直接对应关系，另一方面与TWDP信道参数、SNR和相位噪声标准偏差之间的直接对应关系。结果表明，当信号在TWDP信道上传播时，误码平台值受相位噪声的强烈影响。此外，相位噪声对互信息有相当大的影响。
