Performance Analysis of Coded IFDMA Systems: Maximizing Channel Diversity Order

In this paper, we investigate the use of block spread (BS) and frequency hopping (FH) techniques in coded interleaved frequency division multiple access (IFDMA) systems to achieve maximum channel diversity order. We derive the upper bound on the theoretical bit error rate (BER) that shows the maximum achievable diversity order under maximum likelihood sequence estimation (MLSE). Next, we establish the design criteria for the two different techniques to achieve the maximum diversity order. We also compare the two techniques in terms of their operational complexity and performance. Moreover, we show, through simulation, that the maximum diversity order can be achieved by using a low complexity detector in practical systems instead of the high complexity MLSE.