Optimizing Power for Data Transmissions in Uplink Cell-Free Multi-ABSs Communication Systems

A cell-free (CF) technology is gradually asserting its outstanding advantages by many researches, and it is viewed as a viable technology for use in 6G wireless networks. In this correspondence paper, we examine the performance of uplink CF multiple aerial base stations (ABSs) communication systems where ABSs are described as unmanned aerial vehicles (DAVs) mounted base stations. ABSs are configured with multiple antennas and stochastic distribution in a specific area to serve multiple ground users simultaneously. ABSs estimate the channels during the uplink training stage and then detect data symbols based on the estimated channels. To improve the overall performance of the uplink CF multi-ABS system, the optimization method for data transmission power is proposed. Furthermore, the closed-form of uplink achievable rate is derived based on the matched filtering technique and sequence of linear programs for numerical evaluation. The proposed optimization data transmission power is evaluated while changing several system parameters, such as the number of users, the number of ABSs and pilot sequence length. Our simulation findings demonstrate that the performance of the optimized system is superior to that of the non-optimized system.