Efficiency of multiple access options for 5G and 6G cellular networks
Introduction: IMT2020 (5G) networks can significantly improve the performance of previous generation mobile communication systems in terms of improving broadband multiple access (eMBB - enhanced Mobile Broadband) and pro viding ultrareliable low latency communication (ULLRC - Ultra Low Latency Rellable Communication). The purpose of the work is to review and comparative analysis of multiple access technologies for promising mobile communication networks, which are based on OFDM. Result: The general principles of signal generation and processing when using variants of signals with OFDM using various methods of digital filtering of subcarrier frequencies are considered. For those OFDM options where a cyclic prefix may not be used (FBMC, UFMC), the possibility of increasing the information transfer rate is controversial, since the impulse responses of filters, for example, with FBMC, significantly exceed the duration of information signals, which increases inter symbol interference. Practical significance: The analysis of the general principles for constructing devices for generating and processing physical layer signals for OFDM variants with various methods of additional digital filtering of subcarrier frequencies shows that in all cases there is a significant complication of digital algorithms for generating and processing signals with a practical absence or in some cases a small gain (not more than (0.50.8) dB in relation to signal/noise) by the magnitude of the error per information bit. Based on the results of computer simulation, it is shown that OFDM technology and its variants do not allow obtaining breakthrough solutions in the field of physical layer signal characteristics for 5G and 6G networks, and alternative options for building group signal structures should be considered.