An intelligent link adaptation scheme for OFDM based hyperlans

Adaptive communication is becoming requirement of every communication system for effective utilization of available radio resources. In this approach the transmission parameters like code rate, modulation size and available power are dynamically chosen so that the overall system throughput is maximized while certain constraints like bit error rate are satisfied. In this paper a similar constrained optimization problem is solved by optimally choosing the said parameters with the help of Differential Evolution algorithm with a Fuzzy Rule Based System (DE-FRBS) in an OFDM environment, in this proposal the FRBS is used to adapt the code rate and the modulation scheme according to channel state information (CSI) and desired quality of service (QoS) while DE is employed to find the optimum power vector (OPV) to be transmitted over OFDM subcarriers. Product codes and Quadrature Amplitude Modulation (QAM) are used as coding and modulation schemes respectively. Product codes are considered much powerful in terms of error correction capability. Significance of the proposed scheme is shown by the simulations.