Fluid antenna multiple access (FAMA) is a concept capable of massive connectivity on the same physical channel without the need of precoding or interference cancellation, by exploiting a super-high dimensional received signal in the spatial domain from fluid antenna system (FAS). This letter investigates the use of 5G New Radio (NR) Modulation Coding Scheme (MCS) for FAMA systems to improve its connectivity over block fading channels. In particular, we propose an iterative decoding receiver with iterative interference covariance estimation for the coded FAMA system. Extrinsic information transfer (EXIT) chart is used to analyze the performance of the proposed iterative receiver. Both EXIT chart analysis and numerical results show that the proposed receiver outperforms the one that uses fixed covariance in the block fading channel. Also, the results indicate that coded FAMA can serve 100 user terminals (UTs) at the rate of 0.5 bit/s/Hz under rich scattering.

Compact ultra massive array (CUMA) is a new form of the emerging fluid antenna system (FAS) where a huge number of flexible-position antennas are selected to produce the output signal. By making sure that the in-phase channels (similarly for the quadrature channels) of the desired signal at the selected antenna ports align, it builds an advantage of the desired signal over the interference. It is known that CUMA as a multiple access scheme is able to deal with hundreds of users on the same channel use, in the case of rich scattering, if binary phase shift keying (BPSK) is considered. It is nevertheless unclear if higher-level modulation can bring even greater network rate in this extreme massive connectivity scenario. In this letter, we investigate this situation by presenting the average data rate expression of CUMA when M-ary amplitude shift keying (ASK) is used, assuming a binary symmetric channel. Numerical results reveal that M-ary ASK can indeed raise the rate performance considerably.