Asynchronous Multiple-Access for Low-Latency Communications and Related Waveforms

Abstract

For fulfilling the requirements of real-time communications, wireless communication system has to have ultra-low latency performance, namely latency less than 1ms. However, current cellular network with synchronous multiple-access, such as Long-Term Evolution(LTE), has fundamental limits to accomplish the requirement. In this thesis, asynchronous multiple-access, and related waveform, generalized frequency division multiplexing(GFDM), are studied as one of the alternatives. In the numerical analysis, GFDM and conventional modulation methods, such as single carrier frequency-division multiple-access(SC-FDMA) and orthogonal frequency-division multiplexing(OFDM) modulations, are compared in the asynchronous uplink multiple-access environment with both link-level simulation(LLS) and system-level simulation(SLS). In the comparison, GFDM shows greater performance in the high signal-to-noise ratio(SNR) regime due to the better out-of-band emission performance than conventional modulation methods.