A simple proportional fair scheduling for downlink power domain non-orthogonal multiple access systems

Abstract

Currently, non-orthogonal multiple access technologies have gained high relevance in wireless multi-user broadband communications. Many papers have shown that non-orthogonal multiplexing can significantly increase the capacity of the system. Despite this, it technology is still far from practical implementation due to unresolved issues. One such issue is radio resource scheduling in communication systems using non-orthogonal multiple access which poses a high computational complexity and turns out to be a problem for a base station with a large number of users it serves. In our paper, we propose our own resource scheduling method for systems with non-orthogonal multiplexing using proportional fair strategy. This method allows for simultaneous resource scheduling in two segments – an orthogonal segment (time-frequency domain) and a non-orthogonal segment (power domain). To assess the effectiveness of the proposed method, we use the developed simulation model of resource scheduling for a communication system with a single cell. The effectiveness of the proposed scheduling method is confirmed by the simulation result, and its use allows achieving the proportional fair strategy implementation. In the final part, we use iterative simulation to compare the throughput of systems with orthogonal and non-orthogonal multiplexing using proposed proportional fair scheduler. The result of comparison showed that using the proposed proportional fair scheduling can increase the system capacity by an average of 28%. The results can be applied to create communication systems with different non-orthogonal multiple access implementations.

Symbol Error-Rate Analytical Expressions for a Two-User PD-NOMA System with Square QAM

“…Now, we need to obtain the probabilities for the corner, inside, and outside symbols, using (14), and put them in (12). Firstly, we obtain the expression for finding the correct decoding probability for x ins .…”

“…The decoding area O ins is limited by two sides in the real and imaginary regions (Figure 1) equally, so, using (13), we have ρ(x ins s ins ) = ρ(R s ins ∈ O ins ) 2 . In turn, ρ( s ins ∈ O ins ) is obtained by (14). As we can see, it is enough to find ρ x ins +y n ∈ O ins and substitute it to (14).…”

“…In turn, ρ( s ins ∈ O ins ) is obtained by (14). As we can see, it is enough to find ρ x ins +y n ∈ O ins and substitute it to (14).…”

“…There is a significant number of PD-NOMA articles; most of them are aimed at the design of new analytical resource scheduling [9][10][11][12][13][14][15] and research of system gains in comparison to OMA systems [16,17]. Mostly, these results are based on the Shannon-Hartley theorem [18] and do not take into account bit error rate (BER) and symbol error rate (SER) performances, which are different from OMA systems.…”

Implementation of scheduling in hybrid power domain non‐orthogonal multiple access system considering adaptive modulation and coding schemes selection

“…There is a set of works devoted to resource scheduling in PD-NOMA. For example, works [16][17][18] consider PF scheduling; in the literature [19], subcarrier and power allocation problems are studied, and we introduce our own approach to ER scheduling in the literature [20]. The significant number of papers is devoted to the power allocation issue and its optimization without considering the time-frequency allocation.…”