An effective combination of terahertz band NOMA and MIMO system for power efficiency enhancement

Abstract

Terahertz (THz) band communication is extensively used to reach future communication needs for large capacity. Moreover, the multiple input multiple output (MIMO) and Non-orthogonal multiple access (NOMA) approach with multi-antenna enable users to share more data with good spectrum efficiency.Due to its various applications, different research works are done in MIMO and NOMA. But the existing approach used in NOMA-MIMO has a major limitation in power efficiency. Hence, this research work is presented for maximizing power efficiency. The power efficiency is improved effectively using the THz-NOMA-MIMO system in the presented approach. Initially, users are clustered effectively by utilizing the enhanced fuzzy c-means clustering (EFCM) approach. Afterwards, hybrid precoding with threshold orthogonal matching pursuit (TOMP) approach is presented for generating the hybrid precoding vectors. Here, optimal precoding vectors are generated using the geometric distance-based TOMP approach. This process eliminates the interference present in the data communication, thus improving power and spectral efficiency. Finally, the weight-based distributed power efficient algorithm (WDPEA) achieves the finest power allocation. These combinations of effective approaches enhance the power and spectral efficiency. The presented methodology is implemented in the working platform of MATLAB. The performance of the presented approach is examined with the different existing approaches in regards to spectral efficiency, energy efficiency, effective capacity, and the mean squared error. When the users are at 20, the sum spectral efficiency of existing zero forcing (ZF) is 21, regularized zero forcing (RZF) is 54, maximum ratio transmission (MRT) is 71, and the proposed method is 77 bit/s/Hz. When the signal to noise ratio at 25 dB, the energy efficiency of existing time division multiple access (TDMA) is 1.24, digital MIMO is 1.21, orthogonal multiple access (OMA) is 1.23, weighted NOMA is 1.35, and the proposed method is 1.38 bit/joule/Hz. The proposed method gets better results when compared to other methods.

Joint resource allocation and power allocation scheme forMIMOassistedNOMAsystem

“…Terahertz (THz) communication is becoming more popular, providing a high-speed data rate and a frequency range between .1 and 10 THz. 10 The THz band have a magnitude order of 3 to 4, which is much greater than the present WC band. These bands are highly recommended in mobile phones' capability of effectively providing larger bandwidth.…”

“…Terahertz (THz) communication is becoming more popular, providing a high‐speed data rate and a frequency range between .1 and 10 THz 10 . The THz band have a magnitude order of 3 to 4, which is much greater than the present WC band.…”

Performance evaluation of Non‐Orthogonal multiple access system based on outage probability and power consumption

“…The spectrum efficiency of conventional OMA techniques like frequency division multiple access (FDMA) and time division multiple access (TDMA) is low when users with poor channel quality are utilizing the available bandwidth 3 . Nonetheless, users of NOMA systems communicate at the same frequency, time, and code while using different power levels 4 . It has been demonstrated that by using linear superposition coding (SC), one can obtain the capacity region of degraded single input single output (SISO) Gaussian broadcast channels (BCs) 5,6 …”