Low Complexity Multi Carrier Multiple Access with Cyclic Delay Diversity

In this paper, the performance of Discrete Fourier Transform (DFT) precoded Orthogonal Frequency Division Multiple Access (OFDMA) schemes with interleaved and with blockwise subcarrier allocation is investigated and compared. Transmission with one transmit antenna is compared to transmission with multiple transmit antennas using Cyclic Delay Diversity (CDD). It is shown that the investigated DFT precoded OFDMA schemes with CDD provide low computational complexity and good power efficiency due to low envelope fluctuations of the transmit signal at each transmit antenna. Moreover, it is shown that, depending on the data rate, for one transmit antenna interleaved subcarrier allocation results in a significant performance gain compared to block allocation, whereas for multiple antennas this gain reduces. However, it is shown that even for high data rates DFT precoded OFDMA with interleaved subcarrier allocation is shown to outperform the scheme with block allocation.