Low Complex and High Reliable Resource Allocation for Multiuser OFDM System

This paper deals with our investigations into improving the performance of orthogonal frequency division multiple access (OFDMA) system with low computational complexity. In the proposed scheme, by taking attribute of a user channel like channel capacity decrease rate, subcarriers are allocated depending on the individual users' priority. This scheme is high reliable technique by ordering the capacity decrease rate and allocating subcarriers to users depending on the proposed user' priority. Also we apply error-based bit allocation scheme according to channel condition. And to reduce the computational complexity and iterations until reaching a final allocation, simplified adaptation based on bit error rate (BER) is suggested and compared with original algorithm. As the channel evaluation parameter, signal to noise ratio (SNR) estimation method is used. Our proposed scheme is simulated in comparison with a conventional resource allocation scheme. It is shown that proposed method demonstrates better results than the simulated schemes.