# Mine Intelligent Receiver: MIMO-OFDM Intelligent Receiver for Mine Information Recovery
## 4 Experimental Demonstration
Especially for BPSK signals and QPSK signals, the mine smart receiver can accurately recover the initial information with similar performance. To validate the information recovery capability of smart receivers with different antenna combinations, the experiment set the antenna combinations as 2 \(\times\) 1, 2 \(\times\) 2, 3 \(\times\) 2. 16-bit raw information bit streams were randomly generated. Channel coding was performed using (7, 4) Hamming codes, followed by BPSK digital modulation. The Nakagami fading channel coefficient m was set to 1, the Eb/No range was 0-10 dB, and the step size was 1 dB. Figure 9: Comparison of information recovery capability for different modulation methods. Observe Figure 11. When the antenna combination was \(2\times 1\) and Eb/No was 10 dB, the conventional reception bit error rate was only \(10^{-3}\) and the intelligent reception bit error rate was close to \(10^{-4}\). The accuracy of information recovery for both conventional and intelligent reception was not satisfactory, which indicates that the change in the number of antennas has a greater impact on the intelligent receiver in the mine. We conjecture that the main reason is that the decrease in the number of receiving antennas corresponds to a decrease in the amount of data used for model training under the same conditions, and the model fails to reach the optimal state. Another state can be found. For conventional receivers, the antenna combinations of \(2\times 2\) and \(3\times 2\) are close to each other in terms of information recovery capability. This indicates that there is an upper limit to improve the information recovery capability of the conventional receiver by increasing the antennas. However, there is still a significant performance improvement for the smart receiver. This indicates that there is room for further improvement in the antenna combination for the smart receiver. To validate the end-to-end information recovery capability of smart receivers in dynamic environments, three channel scenarios, Eb/No = 0 dB, Eb/No = 3 dB, and Eb/No = 6 dB, were selected to represent the mining face scenario, the occlusion scenario, and the long straight channel scenario in the mine, respectively. A 16-bit raw information bit stream was randomly generated. In addition, the channel encoding was (7, 4) Hamming code and BPSK digital modulation was used. The Nakagami fading channel coefficient m was set to 1, and the number of transmitting/receiving antennas were both 2. Figure 10: Comparison of information recovery capability for different modulation methods. Observing Figure 12, it was found that the information recovery accuracy of the mine smart receiver model designed in this paper was higher than that of the conventional receiver in all dynamic scenarios. The three channel scenario changes were distinguished obviously, and the scenario transition area was basically the same. At scenario 3, the BER of the mine smart receiver was lower than \(10^{-3}\), and the performance of the smart receiver information recovery ability was stable at the same scenario. Due to the complex working scenarios of coal mine communication systems, communication data loss due to unexpected situations is a problem that needs to be dealt with. Therefore, we specifically considered the end-to-end information recovery performance of the intelligent receiver in case of data loss. The randomly generated 16-bit original information bit stream channel coding using (7, 4) Hamming code and digital modulation method was BPSK. Data loss degrees (ratio of lost data volume to complete data volume) were 1%, 3%, 5%, and 10%. The set Nakagami fading channel coefficient m was 1, and the number of transmitting/receiving antennas was 2. The Eb/No range was 0-10 dB, and step size was 1 dB.