Abstract
Sparse code multiple access (SCMA) is one of the promising candidates for new radio access interface. The new generation communication system is expected to support massive user access with high capacity. However, there are numerous problems and barriers to achieve optimal performance, e.g., the multiuser interference and high power consumption. In this paper, we present optimization methods to enhance the spectral and energy efficiency for SCMA with individual rate requirements. The proposed method has shown a better network mapping matrix based on power allocation and codebook assignment. Moreover, the proposed method is compared with orthogonal frequency division multiple access (OFDMA) and code division multiple access (CDMA) in terms of spectral efficiency (SE) and energy efficiency (EE) respectively. Simulation results show that SCMA performs better than OFDMA and CDMA both in SE and EE.
Highlights
In the history of mobile communication network development [1], multiple access technique has evolved from frequency division multiple access (FDMA), time division multiple access (TDMA) and code division multiple access (CDMA) to orthogonal frequency division multiple access (OFDMA), where a fundamental cornerstone is the orthogonality of resource block (RB)
It is found that Sparse code multiple access (SCMA) perfoms better than CDMA and OFDMA both in spectral efficiency (SE) and EE
OFDMA had a better spectral efficiency performance comparing to CDMA at roughly 50 base station (BS), where CDMA spectral efficiency remains stable; OFDMA supports higher modulation and coding leading to a better spectral efficiency, enhancement of reachability and provides a significant improvement in spectral usage comparing to CDMA technology performance
Summary
In the history of mobile communication network development [1], multiple access technique has evolved from frequency division multiple access (FDMA), time division multiple access (TDMA) and code division multiple access (CDMA) to orthogonal frequency division multiple access (OFDMA), where a fundamental cornerstone is the orthogonality of resource block (RB). In the generation of mobile communication system, the demand for massive connection, low latency, high spectral efficiency and energy efficiency has become a vital necessity. This scenario may make a turning point from orthogonality to non-orthogonality [2], [3]. The author in [4] discussed the energy efficiency in CDMA networks for M-QAM (Quadrature Amplitude Modulation) modulation using a game-theoretic framework, taking into consideration of the constellation size that maximizes the EE while satisfying the (QoS) constraint. [7] addressed the problem of efficient utility based power control with convex pricing in uplink CDMA network, taking into consideration of satisfying QoS prerequisites. An efficient power allocation obtained via using a game theoretical framework with convex pricing of users transmission power, results in analytically a Pareto efficiency
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