COMPARISON OF CDMA AND OFDM SYSTEMS FOR BROADBAND DOWNSTREAM COMMUNICATIONS ON LOW VOLTAGE POWER GRID

This paper provides a fair comparison between DS-CDMA (Direct Sequence Code Division Multiple Access) and OFDM (Orthogonal Frequency Division Multiplexing) systems for broadband downstream Power Lines Communications (PLCs). Considered schemes seem particularly suitable for high bit rate broadcast flexible communications on low voltage grid in order to guarantee "last mile" access network. Proposed systems performance is expressed in terms of Bit Error Rate (BER), derived by simulations under the assumptions of frequency-selective multipath fading channel and additive colored gaussian noise according to the in-building networks model, under the same overall working conditions of bandwidth occupation, transmitted power and global data rate.