Development in the cellular system using power division multiple access-PDMA

The model proposed is to develop a system, which handles heavy subscriber traffic in a highly efficient manner as compared to the existing CDMA (IS-95) system. To attain the afore-mentioned, the system incorporates a unique PDMA system along with IS-95. The system proposed is to be implemented in the MAC layer using a protocol. The coverage area of the base station is divided into concentric quantized power levels. Each quantized level is assigned a unique code (q-codes). Every mobile when activated recognizes the quantization level it is in and transmits it to the base station through the control channel. The concatenation of the orthogonal code and q-code is used to distinctly identify every subscriber in the cell. The system supports soft and hard hand-offs without any blips. The concept of neural networks has been employed to handle heavy traffic densities hence resulting in an optimal system. Simulations show a healthy improvement in the overall handling of the subscriber density. The allocation of q-codes increases the number of users in a cell by a factor of n (n = number of the quantization levels) and hence the proposed system has an edge over the conventional CDMA system. In contrast to frequency reuse in GSM, code reuse has been made possible in PDMA.