## 6 Conclusion and Future Work  
In this article, we propose a new modulation which enables high data rate with low complexity for efficient communications toward 5G and beyond. To make the proposal feasible for the 5G communication network, we take into consideration both the receiver and carrier signal to improve the  
Figure 11: 4-QAM 4-SSB shadow applied in orthogonal frequency division multiplexing Guard Interval (OFDM-GI) compared to the relevant modulation schemes in Rayleigh Channel environment. Figure 10: 4-QAM 4-SSB shadow in correlated MIMO compared to the relevant modulation schemes in uncoded system under Rayleigh Channel environment. overall system performance. For this goal, we investigate various modulation schemes and identify the best modulation and transmission scheme using 4-SSB by analyzing the system BER performances under different subcarrier settings to verify the feasibility of the system design. Firstly, we transmit the signal through the uncoded system to minimize the effect of ISI in AWGN and fading multipath channel. The approach of 4-SSB using shadow equalizer can efficiently decrease the complexity of receiver by removing the iterative turbo equalization and decoding process required in a traditional 4-SSB SISO equalizer. In addition, we apply the proposal using turbo coded transport channels with the interleaver parameters as suggested by the V5 GTF's 5G specification regarding multiplexing and channel coding to verify the efficiency and enable the feasibility of the proposal at the same time. Next, we apply the 4-SSB in massive MIMO to serve the huge demand of the user and enable data rate in the 5G network. The evaluation results demonstrated that the proposed system performs well in the case of \(64\times 64\) MIMO and \(32\times 32\) MIMO under the AWGN and Rayleigh channels. We also apply the correlation Rayleigh to realize a realistic scenario in the ideal case toward 5G communications. Typically, we show the improved performance of the proposal over 64-QAM with coding rate 2/3 when using Turbo code for the coded environments. Besides, we achieve the lowest value of SNR in OFDM-GI. To enable a complete modulation scheme in various environments toward 5G, handling the Doppler effect and mobility will be our focus points in future work. Also, besides turbo code, we have the plan to conduct the proposed 4-SSB modulation scheme with other promising source coding techniques for 5G implementation, including Polar code with successive cancelation list and linear BLOCK error correction code, and low-density parity-check code (LDPC) with sum-product and linear error correction code. In addition, we will conduct the evaluations using sensors to verify the efficiency of the proposal for the feasible network deployment as a practical fulfillment of massive machine-type communications over MIMO for the next-generation wireless communication systems. Also, as the collected data at all sensor nodes can be interleaved, the effect of fading between the access points and each modulated sensor node can be diminished with increased data rate for various radio applications in IoT sensor-enabled communications. Conceptualization, M.M.A., Q.N.N., and G.-I.O. ; Data curation, M.M.A. ; Formal analysis, M.M.A. and Q.N.N. ; Investigation, M.M.A., Q.N.N., and G.-I.O. ; Methodology, M.M.A. and Q.N.N. ; Project administration, T.S. and Q.N.N. ; Resources, M.M.A. ; Software, M.M.A. ; Supervision, T.S. ; Validation, M.M.A. and Q.N.N. ; Visualization, M.M.A. and Q.N.N. ; Writing--original draft, M.M.A. and Q.N.N. ; Review and Editing, Q.N.N. and M.M.A. [PERSON]'s work has been supported by the Waseda University Grant for Special Research Projects under Grant number 2019C-174. We would like to thank all the reviewers and editors for their valuable comments and suggestions that helped improve this research study.