دانلود رایگان مقاله نرخ مجموع GFDMA ناهمزمان و SC-FDMA برای اتصال بالایی 5G

Abstract

The fifth generation (5G) of mobile communication envisions ultralow latency less than 1 ms for radio interface. To this end, frameless asynchronous multiple access may be needed to allow users to transmit instantly without waiting for the next frame start. In this paper, generalized frequency division multiple-access (GFDMA), one of the promising multiple-access candidates for 5G mobile, is compared with the conventional single-carrier FDMA (SC-FDMA) in terms of the uplink sum rate when both techniques are adapted for the asynchronous scenario. In particular, a waveform windowing technique is applied to both schemes to mitigate the inter-user interference due to non-zero out-of-band emission.

5. Conclusion

In this paper, the PSD and uplink sum rate of SC-FDMA and GFDMA with windowing have been compared in the AWGN channel. Owing to low OOB emission in the GFDM PSD, the uplink sum rate of GFDMA becomes higher than that of SC-FDMA in the scenario where the number of guard band subcarriers is small—i.e., high user density with K > 4— or where the SNR is higher than 15 dB—i.e., ICI dominates noise. Apart from the sum rate, the peak-to-average-power ratio in GFDM, which is an also important performance measure in the uplink, can be reduced significantly as in SC-FDM by employing the DFT spreading technique [5].