Secure Sum-Rate-Optimal MIMO Multicasting over Medium-Voltage NB-PLC Networks

We propose a multiple-input multiple-output orthogonal frequency-division multiplexing transceiver for narrowband power-line communication applications in multi-user medium-voltage multicasting networks. The 3-phase medium-voltage multicasting network is modeled as a 2-input/3-output multiple-input multiple-output frequency-selective channel over the 3-500 kHz frequency band. We design the optimal spatial precoder, spatial power allocation, and frequency bit loading profile which maximize the sum-rate of the multicasting groups. In addition, we propose two schemes to secure data transmission through the two-group multicasting network. The first scheme secures the network when the eavesdropper is a user in one of the two multicasting groups and, hence, its channel state information is known at the transmitter. The second scheme secures the multicasting network from external passive eavesdroppers and, hence, the channels between the transmitter and the eavesdroppers are assumed to be unknown at the transmitter. The secrecy rate is evaluated for both scenarios.