Adaptive coding for OFDM based systems using generalized concatenated codes

Orthogonal frequency division multiplexing (OFDM) is considered to be a promising candidate for future high-speed wireless communication systems. We present an adaptive coding scheme for OFDM based systems using generalized concatenated codes. We study the performance of HIPERLAN/2 after encoding with the proposed coding scheme and compare it to the standard convolutional coding scheme currently used. The criterion of our study is the optimization of the throughput. Through the adaptive scheme, we propose a modulation selection based on the average quality of the channel, and a code assigning method for the different sub-channels that adapts to the channel conditions. We argue that the proposed scheme protects the information better than the ones in conventional systems, since the latter do not take advantage of the individual sub-channel condition. Our simulations show that a lower packet error rate can be accomplished for even higher throughput.