IFDMA: A Scheme Combining the Advantages of OFDMA and CDMA

Future mobile radio systems must fulfill challenging requirements. Some requirements are met by single-carrier-based multiple access (MA) schemes such as CDMA and others by multi-carrier-based MA schemes like OFDMA. MA schemes integrating the characteristics of both are receiving more and more attention. In this article, candidate MA schemes based on the idea of integration are summarized and classified using a new framework. Moreover, interleaved frequency division multiple access (IFDMA) is shown to be a scheme that combines the advantages of both CDMA and OFDMA and is a promising candidate MA scheme, especially for non-adaptive transmission in the uplink of future mobile radio systems.