## 5 Discussion  
In Section 3, the architecture of the proposed model was outlined, and the evaluation methods applied on each level were explored. An example of the proposed model was presented in Section 4. In this section, the performance of the proposed model is discussed.  
(1) The proposed model can quickly evaluate whether any of four kinds of interference margins are present between transmitters and receivers.  
(2) The proposed model can quickly evaluate whether any of three kinds of signal spectrum interference are present between transmitters and receivers.  
(3) The decrease in receiver sensitivity is one of the important factors affecting vehicle communication and one of the important indicators of vehicle electromagnetic compatibility. The traditional model does not evaluate the change in receiver sensitivity. The proposed model obtains the terrain profile through a digital map and obtains the actual distance of vehicle communication. Considering feed loss, antenna polarization mismatch loss, and propagation loss, the actual power and sensitivity decline of the receiver were calculated. The sensitivity of the receiver was evaluated through comparison with the vehicle EMC indicators.  
(4) The signal transmission of the communication system is based on vehicle-mounted antennas. Due to the various types and numbers of antennas mounted on the vehicle, antenna isolation will be reduced, and the quality of signal transmission will be affected. However, traditional models do not evaluate the degree of isolation between antennas. The proposed model can be used to calculate the decreasing degree of isolation of the vehicle-mounted antenna and evaluate it by comparing it with the vehicular communication system EMC indicators.  
(5) In the past, most types of communication systems were analog systems, for which traditional models are suitable. However, with the development of electronic science and technology, most communication systems are now digital, and traditional evaluation mod  
Figure 14: Relationship between BER and SNR for seven channel-coding modes.  
els are less efficient. The proposed model is suitable not only for evaluating analog systems but also digital systems. If analog and digital systems are used for voice communication, they can be evaluated using speech clarity and BER, respectively.  
(6) The most important function of an armored vehicular communication system is the ability to effectively and continuously communicate with other vehicles and C\({}^{3}\)I systems. Various communication systems have different requirements for communication distance under different conditions. Traditional models cannot be used to evaluate changes in communication distance. The degree of decrease in communication distance can be determined using the proposed model.  
(7) In this article, a link simulation model was established based on an actual communication system, and the influence of the modulation mode and coding mode on the bit error rate of the analyzed armored vehicle digital communication system was analyzed. The modulation mode and coding mode with the best electromagnetic compatibility were determined. The proposed model can evaluate BER by comparing it with vehicular communication system EMC indicators.  
In summary, each evaluation model has its advantages and disadvantages. The evaluation model proposed in this paper is especially suitable for armored vehicle communication systems.