Adaptive OFDMa scheme for spectrum and power allocation

The paper presents a new approach of optimal spectrum and power allocation for orthogonal frequency-division multiplexing (OFDM) modulation schemes. The algorithm is implemented using a parallel processing method, where each transmitted bit will minimize its cost functions, by choosing the spectrum and powers that suit better the interference pattern. The optimization problem is treated as a constrained problem, for which the optimal spectrum and power are designed based on modified gradient approach. The convergence of the algorithm was discussed. A conventional correlator implemented at the receiver part will provide immunity to perturbing interference for the optimal spectrum and power allocation. The validity of our system was confirmed by simulation.