Cache-Enabled MIMO Power Line Communications With Precoding Design in Smart Grid

Power line communication (PLC) is an attractive approach to provide information transfer services for the smart grid. A crucial issue in PLC networks is how to achieve reliable transmission for rural and remote users against severe fading and impulsive noise in an economic way. To address this problem, we propose a cache-enabled multiple-input and multiple-output (MIMO) PLC network to improve transmission reliability and minimize downloading cost for users. First, we deploy a local cache at each PLC access unit to store popular content requested by users according to a popularity-based data placement. As such, the proposed cache-enabled scheme can not only bring popular data close to users at the edge of PLC networks but also reduce the PLC backhaul burden. Second, in the data delivery stage, we propose a precoding design for each access unit and formulate average downloading price for each user. In particular, we solve optimal precoding vectors to simultaneously meet the target transmission rate and minimize the price of each user through an efficient algorithm. Numerical results corroborate that our cache-enabled MIMO PLC network can guarantee the transmission reliability whilst reducing the downloading price compared with the existing related works.