Non-Orthogonal Multiple Access (NOMA) is very useful in 6G network system requirements, also a solution to improve spectral efficiency and user fairness. NOMA gives a new dimension that increases spectral efficiency, massive connectivity, low transmission latency, and cost of signalling. Hence, NOMA as multiple access schemes can solve user problems from scarce time or frequency domain resources. 6G data traffic reduction by storing the most popular contents in advance at the network edge whereas content caching restricts duplicate of multiple data transmission. The most concerning problem would be the impact of a few subcarriers on the PAPR reduction in NOMA systems is needed to avoid signal degradation. The objectives of this research are to reduce the PAPR. The method applied is by using the Huffrith algorithm with the APSK modulation technique in the NOMA system. The results were obtained by comparing the contribution method with variations of the coding technique, which is the Huffman, Arithmetic, and Huffrith algorithms. Huffrith algorithm is the higher improvement using 512 subcarriers with 8.6 % and PAPR values of 8.5 dB. For 1024 subcarriers get 8.7 dB and 12.12% percentage of improvement.

In this paper, the high-rate Quasi-Cyclic Low-Density Parity -Check (QC-LDPC) as an error correction code is contributed for Non-orthogonal Multiple Access (NOMA) systems with high-frequency spectrum efficiency. High PAPR will affect the signal degradation and all the methods applied in the NOMA system are solving the problem of scarce time or frequency domain resources. The objectives of this paper are achieved by reducing the PAPR using Huffrith algorithms with QC-LDPC in the NOMA system. Huffrith algorithm combined with QC-LDPC to reduce the peak-to-peak average ratio in the 6G network. This method simulates using the 512 APSK modulation technique. The results were obtained by differentiating the contribution method with four types of coding techniques, which are an original data signal, Huffman, Huffrith, and Arithmetic algorithms. Besides, also differentiate three scenarios without error correction codes, LDPC codes, and QC-LDPC codes to compare which is better and more suitable using the NOMA system. Compared with different multiple access shows results that NOMA systems get highest percentage of improvement is 16.95% and 9.8 dB. Next results, seems QC-LDPC is better by getting the highest percentage of improvement is 22.31% and 9.40 dB compare with others.