# Mine Intelligent Receiver: MIMO-OFDM Intelligent Receiver for Mine Information Recovery
## 4 Experimental Demonstration  
In this section, the practical performance of the intelligent receiver for the mining MIMO-OFDM system proposed in this paper is verified by experimental simulations. In this paper, MATLAB2019b is used as an experimental platform to build a model of a mine MIMO-OFDM communication system that generates simulation datasets, and the intelligent receiver network model is built on an NVIDIA RTX3090 GPU using the Tensorflow2.0 deep learning framework. For the mine fading channel, we consider mine large scale fading and small scale fading. Large-scale fading involves the roughness and inclination of the tunnel  
Figure 7: Network structure of mine intelligent receiver based on VOVNet. walls in the mine channel, as well as the fading coefficient of some dust; Nakagami fading is chosen as the small-scale fading model, and the damage of the mine fading channel to the transmitted signal is characterized by varying the fading coefficient m.  
To verify the end-to-end information recovery capability of the mine smart receiver under different channel scenarios, a 16-bit raw information bit stream was randomly generated and the channel was coded using (7, 4) Hamming codes, followed by BPSK digital modulation. Different coefficients m under Nakagami fading channel model were selected. m values were chosen to contain 0.5, 1, and 2, m = 0.5 for one-sided Gaussian distribution and m = 1 for Rayleigh distribution. m values are larger, and a smaller fading degree indicates a better channel state. The quantity of antennas receiving/transmitting was set to 2, the Eb/No (bit signal-to-noise ratio in dB) range was 0-10 dB, and the step size was 1 dB. A total of 20,000 training samples and 10,000 test samples were generated under each Eb/No, totalling 220,000 training samples and 110,000 test samples. Observing Figure 8, it was found that, for different channel scenarios, smart reception had a superior information recovery performance compared to conventional reception. The error bit rate of conventional receivers reached only \(10^{-3}\) at Eb/No of 10 dB and m = 0.5 due to the accumulated error, while the error bit rate of the intelligent receiver designed in this paper reached \(10^{-5}\). Overall, the change of channel fading had little effect on the smart receiver, which indicates that the smart receiver is less sensitive to the channel environment transformation, has good robustness, and shows more stable noise resistance performance. Figure 9 shows the comparison of the information recovery performance of the mine smart receiver designed in this paper (noted as a multi-label classifier reception) and the literature [20] receiver model (noted as the binary classifier reception). It can be found that, although both belong to the overall optimized information recovery method, the multi-label classifier receiver model has a more excellent information recovery capability. When Eb/No = 10 dB, the error bit rate of the receiver model designed in this paper is lower than \(10^{-5}\), which is slightly better than the binary classifier reception model. Figure 8: Comparison of information recovery capability for different channel scenarios. To demonstrate the end-to-end information restoration capability of the smart receiver with different digital modulated signals, we randomly generated 32-bit raw information bit stream. Three digital modulation methods were set: BPSK, QPSK and 16 QAM, the Nakagami fading factor was chosen as 1, the number of transmitting/receiving antennas was 2, and the range of Eb/No was 0-10 dB in 1 dB steps. Observing Figure 10, it was found that conventional receivers had significant variability for different modulated signals. The performance of information recovery was poorer for higher order modulation. The mine smart receiver designed in this paper was more adaptable to signal modulation variations. Although the BER of the 16 QAM signal was about \(10^{-4}\) at Eb/No = 10 dB, it was better than the conventional receiver overall.