Abstract: A computer-implemented method for artificial intelligence (AI) based risk/value assessment of a geographic area includes performing feature engineering to contextually enrich collected data. Three datasets are generated from the contextually enriched data, where a first dataset is generated by combining positive samples of the contextually enriched collected data with hard negative samples of the contextually enriched data, a second dataset is generated by combining the positive samples with soft negative samples of the contextually enriched data, and a third dataset is generated by combining the positive samples, hard negative samples, and soft negative samples. A machine learning model is trained to generate three different types of predictions for the risk/value assessment of the geographic area based on the three generated datasets.

Abstract: This invention provides a relay precoder selection method for two-way amplify-and-forward multiple-input multiple-output (MIMO) relay systems and communication devices using the selection method or the selected relay precoder. According to the relationship between a relay precoder and the singular values of the effective MIMO channels, a set of candidate relay precoders are constructed based on the singular vector subspaces of cascaded MIMO channels, and one of them is selected for meeting a specific design criterion, such as the minimum sum of mean-squared errors, the maximum sum of channel capacities, and the minimum or maximum sum of condition numbers, where the condition number is defined as the ratio of the largest to the smallest singular value of a MIMO channel. As compared with the iterative design methods with the best performance, this invention achieves close performance while requiring much lower computational complexity.

Abstract: This invention provides a relay precoder selection method for two-way amplify-and-forward multiple-input multiple-output (MIMO) relay systems and communication devices using the selection method or the selected relay precoder. According to the relationship between a relay precoder and the singular values of the effective MIMO channels, a set of candidate relay precoders are constructed based on the singular vector subspaces of cascaded MIMO channels, and one of them is selected for meeting a specific design criterion, such as the minimum sum of mean-squared errors, the maximum sum of channel capacities, and the minimum or maximum sum of condition numbers, where the condition number is defined as the ratio of the largest to the smallest singular value of a MIMO channel. As compared with the iterative design methods with the best performance, this invention achieves close performance while requiring much lower computational complexity.