Adaptive Resource Allocation for OFDM Systems using Fuzzy Rule Base System Water-filling Principle and Product Codes

Adaptive resource allocation is one the key characteristics of almost all communication systems nowadays. In this technique, available resources are optimally used to enhance the overall throughput of system while satisfying certain number of constraints. In this paper a similar constrained optimization problem is formulated and a fuzzy, rule based system (FRBS) is designed and used for solution of the problem. The parameters being optimized for the system are practical channel codes, modulation symbol and the transmit power. FRBS suggests how to change coding scheme and modulation symbol while water-filling algorithm suggests the adaptive power according to varying channel state information in Orthogonal Frequency Division Multiplexing (OFDM) channel so that throughput can be maximized. Product codes, Quadrature Amplitude Modulation (QAM) are used as FEC and Modulation scheme respectively. Moreover, a modified iterative algorithm is used for decoding the product codes. Significance of proposed scheme is shown by simulations.