Multiple access over wireline channels using orthogonal signaling

With the emerging high-rate wireline channels, multiple access is inevitable. In this paper the multiple access problem over wireline channels is solved using orthogonal signaling. The 2-D FIR CAP/QAM based line code is extended to a multi-dimensional system to accommodate multiple access topology. Using the well known Orthogonality Division Multiple Access, ODMA, we can achieve better theoretical and practical advantages over Time Division Multiple Access (TDMA) and Frequency Division Multiple Access (FDMA). The problem of increasing the number of dimensions is stated as a minimax optimization problem, then solved using sequential quadratic programming. 3,4, and 6-dimensional systems are introduced to support multiple access applications. The superiority of ODMA over other multiple access techniques is shown in light of the receiver equalizer performance. Computer simulations are carried out to evaluate the performance of the new line code.