Abstract
This paper proposes coordinated beamforming (CB) that works over non-orthogonal multiple access (NOMA) scheme integrated with spatial modulation (SM), termed as CB NOMA-SM, to improve capacity and user fairness. User capacity, ergodic sum capacity (ESC), and user fairness of K number of coordinated base stations (BSs) are simulated and analyzed by comparing them with joint transmission coordinated multi-point based NOMA with SM (JT-CoMP NOMA-SM), NOMA, and orthogonal multiple access (OMA). The results show that the proposed system outperforms the other schemes both in ESC and user fairness due to the enhancing CEU while CCU capacity still can be maintained.
Highlights
Non-orthogonal multiple access (NOMA) is one of multiple access candidates in next-generation wireless communications, which provides higher spectral efficiency than orthogonal multiple access (OMA) [1], [2]
Considering the number of center user (CEU) that may be equal to or more/less than cell center user (CCU) in practice, joint transmission coordinated multi-point (CoMP) with virtual user pairing-based NOMA (JT-CoMP VP-NOMA) [16] and joint transmission CoMP works over NOMA integrated with spatial modulation (JT-CoMP NOMA-SM) [17] are proposed to handle multiple CEUs as well as the inter-cell interference (ICI) issue
This paper provides a closed-form solution for ergodic sum capacity (ESC) of the proposed system, which is derived through a mathematical analysis by considering imperfect successive interference cancellation (SIC) and imperfect channel state information (CSI)
Summary
Non-orthogonal multiple access (NOMA) is one of multiple access candidates in next-generation wireless communications, which provides higher spectral efficiency than orthogonal multiple access (OMA) [1], [2]. Considering the number of CEU that may be equal to or more/less than CCUs in practice, joint transmission CoMP with virtual user pairing-based NOMA (JT-CoMP VP-NOMA) [16] and joint transmission CoMP works over NOMA integrated with spatial modulation (JT-CoMP NOMA-SM) [17] are proposed to handle multiple CEUs as well as the ICI issue. Based on the evaluation of JT-CoMP NOMA-SM, a CoMP user gets high data rate because it gets signals from multiple coordinated BSs. Assuming there are K number of coordinated BSs within N number of cells and the number of SM antenna is fixed, a fairness problem occurs when the number of coordinated BS is increased. By considering superiority of SM such as improving capacity, mitigating ICI and handling multiple CEUs [17]–[20], the SM can be implemented in CB NOMA where one transmitting antenna is activated to transmit symbols at a particular time.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
