Maric Almir, Kaljic Enio, Njemcevic Pamela
Department of Telecommunications, Faculty of Electrical Engineering, University of Sarajevo, Zmaja od Bosne b.b., Kampus Univerziteta, 71000 Sarajevo, Bosnia and Herzegovina.
Sensors (Basel). 2021 Nov 12;21(22):7513. doi: 10.3390/s21227513.
Two-wave with diffuse power (TWDP) is one of the most promising models for the description of small-scale fading effects in 5G networks, which employs mmWave band, and in wireless sensor networks deployed in different cavity environments. However, its current statistical characterization has several fundamental issues. Primarily, conventional TWDP parameterization is not in accordance with the model's underlying physical mechanisms. In addition, available TWDP expressions for PDF, CDF, and MGF are given either in integral or approximate forms, or as mathematically untractable closed-form expressions. Consequently, the existing TWDP statistical characterization does not allow accurate evaluation of system performance in all fading conditions for most modulation and diversity techniques. In this regard, physically justified TWDP parameterization is proposed and used for further calculations. Additionally, exact infinite-series PDF and CDF are introduced. Based on these expressions, the exact MGF of the SNR is derived in a form suitable for mathematical manipulations. The applicability of the proposed MGF for derivation of the exact average symbol error probability (ASEP) is demonstrated with the example of M-ary PSK modulation. The derived M-ary PSK ASEP expression is further simplified for large SNR values in order to obtain a closed-form asymptotic ASEP, which is shown to be applicable for SNR > 20 dB. All proposed expressions are verified by Monte Carlo simulation in a variety of TWDP fading conditions.
双波漫射功率（TWDP）是描述5G网络中毫米波频段以及部署在不同腔体环境中的无线传感器网络中小尺度衰落效应最有前景的模型之一。然而，其当前的统计特性存在几个基本问题。首先，传统的TWDP参数化与模型的潜在物理机制不一致。此外，现有的TWDP概率密度函数（PDF）、累积分布函数（CDF）和矩生成函数（MGF）表达式要么是积分形式或近似形式，要么是数学上难以处理的闭式表达式。因此，现有的TWDP统计特性无法对大多数调制和分集技术在所有衰落条件下的系统性能进行准确评估。在这方面，提出了基于物理原理的TWDP参数化并用于进一步计算。此外，还引入了精确的无穷级数PDF和CDF。基于这些表达式，以适合数学运算的形式推导出了信噪比（SNR）的精确MGF。以M进制相移键控（M-ary PSK）调制为例，证明了所提出的MGF在推导精确平均符号错误概率（ASEP）方面的适用性。为了得到闭式渐近ASEP，对推导得到的M进制PSK ASEP表达式在高SNR值时进行了进一步简化，结果表明该渐近ASEP适用于SNR > 20 dB的情况。所有提出的表达式都在各种TWDP衰落条件下通过蒙特卡罗模拟进行了验证。
