Sum-rate-optimal dual-QoS MIMO multicasting over medium-voltage NB-PLC networks

We propose a multiple-input multiple-output (MIMO) orthogonal frequency-division multiplexing system for narrowband power-line communication applications in multiuser medium-voltage (MV) multicast networks. The 3-phase MV multicast network is modeled as a 2-input / 3-output MIMO spatial channel over the 3-500 kHz frequency band. We optimize the precoder design to maximize the signal-to-interference-plus-noise ratio at each receive node assuming either a matched filter receiver or a minimum mean square error linear receiver. The performance is evaluated in terms of the achievable sum-rate for a group-based multicast network under two different grouping criteria. The first is an equal-priority criterion where the users in each group receive the same message and all network users operate at the same bit error rate. The second criterion is quality-of-service based and guarantees a lower bit error rate to the premium users compared to the standard users. We quantify the sum-rate gains of multicasting over broadcasting where all users are combined in one group.