Non-orthogonal multiple access (NOMA) will play an imperative part in an advanced 5G radio arrangement, owing to its numerous benefits such as improved spectrum adeptness, fast data rate, truncated spectrum leakage, and, so on. So far, NOMA undergoes from peak to average power ratio (PAPR) problem, which shrinks the throughput of the scheme. In this article, we propose a hybrid method, centered on the combination of advanced Partial transmission sequence (PTS), Selective mapping (SLM), and bacteria foraging optimization (BFO), known as PTS-BFO and SLM-PTS. PTS and SLM are utilized at the sender side and divide the NOMA into several sub-blocks. An optimal phase factor is achieved by the BFA and combined with the NOMA sub-block, where a low peak power value is obtained. Further, we estimate the bit error rate (BER) and PAPR of BFA in the SLM and PTS technique. The simulation outputs reveal that the PTS-BFO outperforms the traditional peak power minimization approaches and moderates the complexity of the system. It is concluded that the proposed algorithm is not explored for the NOMA waveform.

Orthogonal frequency division multiplexing (OFDM) is currently employed in 4G radio, but it is not considered for the 5G radio system due to its several disadvantages mentioned in [

The PAPR is among the few obstacles to its regularization. PAPR hampers the exhibition of the framework because the usage of the OFDM transmission conspires at the sender of the framework PAPR is regarded as one of the significant concerns in designing the FBMC framework. An escalation in PAPR decreases the excellence of the system by increasing the PAPR and bit error rate (BER) of FBMC. The design of FBMC is built in filters; Inverse Fast Fourier transforms (IFFTs) and, FFTs. The cluster of filters reduces the spectrum outflow and improves the bandwidth shaping [

In [

In this work, we integrate PTS-BFO and SLM-BFO. Initially, PTS and SLM are applied to the NOMA, and subsequently the BFO phase elements are multiplied by the PTS and SLM-OMA symbols. The diverse combinations of phase factors and sub-blocks are applied to decrease the PAPR of the structure.

The schematic of NOMA is given in

The NOMA signal can be represented as [

where

where

From,

where

Traditionally, PAPR is defined in terms of dB:

To analyze the effect of the reduction method, it is imperative to evaluate the complementary cumulative distribution function (CCDF) of PAPR. The CCDF of NOMA waveform is presented every bit:

BFA is extensively employed as a novel optimization technique. It is based on the nature of

In the proposed algorithm, the main concern is to find the ideal value of the phase factor which can be multiplied by the NOMA symbols for an optimal peak power [

The objective of the projected work is attained in dualistic phases. In the first stage, the advanced SLM and PTS are used for the NOMA signal. It pursues the division of all sub-blocks. SLM and PTS also upsurge the computational intricacy due to the use of IFFTS. In the second phase, we use a BFA to identify an enhanced phase element for SLM, which reduces the PAPR and system complexity.

The NOMA may be represented by equation [

where

A cluster of the filter is applied on

Now, the BFA is applied to obtain an optimal phase sequence for SLM and PTS. The composite phase aspect is expressed as:

where

The NOMA symbol

The preeminent

From

The present work is analyzed by using Matlab-2014. The constraints used in the model are shown in

Scheme | NOMA |
---|---|

Modulation schemes | QAM-256 |

Bandwidth | 16 MHz |

Transmitter and Receiver | Super Coding and Successive Interference cancellation |

Subcarriers | 1024 |

In the presented simulation, we have selected ^{2} V + 8V^{2}), where N is total sub-carriers and

The CCDF for NOMA PAPR is illustrated in the

The BER curve is shown in

To analyze the throughput of the OFDM and NOMA waveform, the BER performance estimation is shown in ^{−3} dB. It indicates that the NOMA obtained a gain of 2.5 dB as compared to the OFDM structure [

The conventional OFDM and proposed NOMA waveform schemes are examined to calculate the peak power performance, indicated in ^{−3} is obtained at the SNR of 10.5 dB and 13.5 dB for the OFDM and NOMA waveform. Hence, it is concluded that the peak power efficiency of NOMA is better than the conventional OFDM structure.

The Power spectrum density (PSD) of NOMA is demonstrated in

In this work, the hybrid PAPR algorithms are implemented for the 256-QAM-NOMA structure. PTS and SLM are regarded as one of the most dynamic methods to decrease the PAPR of the waveforms. It also prompts high computational intricacy. Further, a BFO is implemented to find a suitable phase element for which an optimal PAPR is attained. The conclusions of the simulation reveal that the NOMA with SLM-BFO and PTS-BFO performed better than the traditional PAPR procedures and in particular reduced the complexity of the NOMA structure. In the future, BFA can be combined with a number of advanced PAPR methods for 5G waveform.