Interleaved Orthogonal Frequency Division Multiple Access with Variable Data Rates

Multicarrier transmission systems with a specific subcarrier allocation such as equidistantly interleaved OFDMA or Interleaved Frequency Division Multiple Access (IFDMA) are promising candidates for future mobile radio systems, because they provide many advantages such as high flexibility, good performance and low computational complexity. In this paper, a new method for accommodation of different data rates per user is introduced. It keeps the orthogonality of different users’ signals and at the same time maintains an equidistant subcarrier allocation. It is shown that the performance of equidistantly interleaved OFDMA and of IFDMA for coded transmission over a frequency selective mobile radio channel improves with increasing data rate.