For wireless communication systems, receivers usually work under complex electromagnetic environments and are often susceptible to electromagnetic interference (EMI). With the wide application of pulse signals in various fields, the impact of pulse signals on the receivers of communication system has not been extensively studied. On the one hand, the existing receiver electromagnetic sensitivity (EMS) interference coupling effect is mainly analyzed from the perspective of energy only, without considering of different electromagnetic parameter characteristics of pulse signal, such as pulse width, repetition period, duty cycle and so on. On the other hand, there is a lack of quantitative characterization of typical performance indexes of receiver subject to pulsed interference environment, resulting in insufficient reliability and accuracy of receiver interference degree prediction and electromagnetic compatibility (EMC) evaluation. This paper focuses on the EMS interference coupling effect analysis and EMC evaluation method of receiver under pulsed interference environment. First, based on the analysis of the interference mechanism of the pulse signal on receivers, the formula for the bit error ratio (BER) is derived. Then a system model is proposed to verify the theoretical analysis results through numerical simulation. With the established relationship between the parameters of the pulsed interference and the BER performance of the receiver, a novel EMC evaluation method has been proposed. As a practical application example, the evaluation method is verified via a well-designed experiment on BeiDou Navigation Satellite System (BDS). The experiment shows that the observed phenomena are in good agreement with the conclusions of the proposed evaluation method, proving that the method is applicable to the EMC evaluation of receiver under pulsed signal interference environment.

The received signal of the electronic equipment often depends on its surrounding multidimensional dynamic electromagnetic environment (MDEE) featured with large airspace, high field strength and wide frequency band. This brings great challenges to predict the electromagnetic compatibility (EMC) of the electronic equipment dynamically. As an extension to the conventional equivalent construction (EC) process for the static single-source electromagnetic environment, based on the response of an antenna port, a novel EC method for the dynamical multi-source heterogeneous electromagnetic environment is proposed in this article. By applying this EC method to a radar system under a practical dynamic working scene, an innovative electromagnetic sensitivity threshold test method is carried out in the laboratory. The experimental results show that the theoretically predicted value is in good agreement with the measurement, where the error is less than 1dB. With the methods proposed in this article, the dynamic analysis and prediction of EMC in MDEE can be carried out with the consideration of the characteristics of the electronic equipment, so that the electromagnetic environment adaptability of the electronic equipment can be readily improved.

The electromagnetic environment presents a significant challenge for the dynamic prediction of electromagnetic compatibility (EMC) of electronic equipment due to its wide bandwidth, high dynamics, and large airspace. To address this challenge, we propose a novel method that extends the equivalent construction method for the electromagnetic environment by considering dynamic factors such as antenna rotation and radiation source motion. This method involves establishing a spatial mapping factor and frequency mapping factor model from the radio frequency (RF) port spectral response, which enables the construction of dynamic scenario equivalence and prediction of EMC based on RF port electro-magnetic response characteristics. In laboratory experiments using this method, we constructed dynamic scenario equivalence for radar and proposed a new method for radar EMC prediction. The results showed good agreement between the theoretical predictions and measured values, with an error of only 1 dB when considering the spatial mapping factor and an error of 2 dB when also considering the frequency equivalent mapping. The proposed method can be used for equivalent construction of dynamic scenarios and EMC prediction of electronic devices, leading to improved adaptability of electronic devices to the electromagnetic environment.

Radio frequency power amplifier (PA) is an important part of the transmitter system, which can drive numerous output devices. However, the nonlinear characteristics of PA will cause serious harmonic interference, which leads to electromagnetic interference (EMI) problems. In this article, the nonlinear characteristics and the memory effect of PA are analyzed. The strong nonlinearity region and the weak nonlinearity region are divided according to the strength of the nonlinearity. For the strong nonlinearity, an encoder–decoder-based (E-D-based) artificial neural network model is proposed to predict the harmonic interference of PA. To promote the prediction of high-order harmonics when the input signal is small, a multilayer perceptron model is used for the weak nonlinearity region. The models can effectively predict the first five harmonics of PA, in which the mean absolute error of the fundamental wave is about 0.1 dB, the one of the second-order and the third-order harmonics is about 0.5 dB. Since transfer learning (TL) can simplify the training of the model based on the similarity of different tasks, TL based on model transfer is used to predict the harmonic interference of other PAs according to the existing models. The amount of data required for the modeling of PA can be greatly reduced and the accuracy of prediction can be guaranteed by applying TL. Ultimately, the proposed method can predict the harmonic interference rapidly and accurately according to the known excitation signal so that corresponding measures can be taken to avoid the influence of radiated spurious emission on the use of the sensitive receiving devices in the same electromagnetic environment.

With the increasing complexity and interweaving of noncooperative communication scenarios, communication receivers are increasingly subjected to varied and complex electromagnetic interference, making the prediction of their operational states and performance critical. Currently, modulated and noise interference often exhibit broadband characteristics, rendering existing methods inadequate. Thus, new solutions for broadband interference are urgently needed. To address this issue, this article proposes a multitask physics-informed neural network (MTL-PINN) prediction model based on the function-performance association of receivers, considering both signal processing flow and communication quality. The application scope of the CS105 testing standard is expanded within this framework. Specifically, quantification indicators for broadband interference is introduced for the power spectrum at the antenna port, and by using a 16 quadrature amplitude modulation receiver as an example, the interference quantification indicators are innovatively integrated into the bit error rate calculation formula to construct a knowledge model. Subsequently, the MTL-PINN architecture is designed to effectively merge this knowledge model with test data. Comparative experiments demonstrate that the proposed model significantly reduces the need for extensive test data, while improving prediction accuracy and generalization across diverse interference scenarios, providing an effective tool for assessing the electromagnetic susceptibility of communication receivers under broadband interference.

Massive machine type communications (mMTC) is one of main application cases in 5G, which is supposed to support communications of massive number of machine-type devices (MTDs). Distributed queue (DQ) is a variant of tree splitting protocol which combines an m-ary tree splitting algorithm with a set of simple smart rules, organizing every terminal in one out of two virtual queues. Theoretically, DQ allows access to infinite terminals and is stable under any traffic condition, which alleviates the unstable problem of slotted ALOHA, and is especially suitable for mMTC. However, its theoretical comprehensive performance analysis as well as related statistical characteristics is still missing, which severely restricts the full manifestation of its performance advantages. In view of this, the paper proposes a general performance analysis framework for DQ, with which full probability space of DQ evolution process is presented for the first time. To be more specific, probability distribution function (PDF), mean and variance of throughput, latency and energy consumption of DQ is analytically derived to comprehensively evaluate performance. Taking the IEEE 802.15.4 standard for mMTC as example, numerical results validate the accuracy of the proposed analysis framework and the stability of DQ, present effects of number of MTDs, number of contention slots (m), and maximum number of transmissions (L) on DQ in terms of aforementioned performance metrics. These results together provide good reference to find appropriate value of m and L to balance the performance metrics and enable more practical network optimization.