Three-dimensional carrierless AM/PM line code for the unshielded twisted pair cables

The Carrierless AM/PM (CAP) modulation scheme is a viable alternative for high speed digital transmission for the HDSL/ADSL/VHDSL environments. In this paper, the conventional 2-D CAP system is expanded to a 3-D space. A 50% increase in the system throughput is achieved at the expense of added receiver complexity and some performance degradation. The 3-D signaling is obtained through a minimax optimization process to match the characteristics of the original 2-D system and to achieve perfect reconstruction (PR) condition. The 3-D CAP system is simulated over unshielded twisted pair (UTP) cable environment for baud rate of 150 Mbps.