Joint optimization of SIC decoding order

Optimize the NOMA successive-interference-cancellation decoding order jointly with the transmit powers, CPU frequencies, and pinching-antenna configuration in the uplink PASS-NOMA-MEC system.

Background

The uplink NOMA model fixes the successive-interference-cancellation decoding order according to the initial effective channel magnitudes, with users relabeled so that |h_1|2 \geq \cdots \geq |h_K|2. This order is then held fixed throughout the resource-allocation optimization, which preserves smoothness of the rate expressions with respect to the antenna geometry and coupling lengths.

Jointly optimizing the decoding order together with transmit powers, CPU frequencies, and the PASS configuration is identified as future work. Such an extension would remove the fixed-order restriction and address the interaction between decoding-order selection and the other nonconvex design variables.

References

The decoding order is set at the initial configuration, with users relabeled $k=1,\ldots,K$ so that $|h_{1}|2\ge\cdots\ge|h_{K}|2$, and is kept throughout the optimization; the rates~eq:SINR are achievable under any fixed order, and optimizing the order jointly with the other variables is left to future work.

eq:SINR:

γk=pk∣hk∣2∑i=k+1Kpi∣hi∣2+σ2,Rkoff=Blog⁡2(1+γk),\gamma_k=\frac{p_k|h_k|^2}{\sum_{i=k+1}^{K}p_i|h_i|^2+\sigma^2}, \qquad R_k^{\mathrm{off}}=B\log_2(1+\gamma_k),

— Latency-Aware Uplink NOMA-MEC with PASS: A Feasibility-First Resource Allocation Framework  (2610.17949 - Abolhasani et al., 13 Oct 2026) in Section II-B, “Uplink NOMA with Fixed SIC Order”