As a new non-orthogonal multiple access technology for 5G massive machine type communication scenario, the sparse code (SCMA) has greatly improved spectrum efficiency due to high connection density. SCMA combines QAM (Quadrature Amplitude Modulation) modulation and spreading into codebook set obtain forming gain. The user binary bit data is directly mapped multi-dimensional codewords in transmi...

The hybrid power domain sparse code non-orthogonal multiple access (PD-SCMA) scheme multiplexes users on a single resource element (RE) both in and domains, thus achieving superior spectral efficiency. multiplexing performance of such can be enhanced not only through deployment sophisticated allocation schemes low complexity robust multi-user detectors but also prudent multi-dimensional codeboo...

Low-power Wide-Area Network (LPWAN), as a wireless connection technology of the Internet things, has met requirements power consumption network providers and operators, coverage things equipment. As main LPWAN, Long Range (LoRa) entered stage scale deployment. However, in MAC protocol LoRa, multiple end nodes send data to gateway at same time, which will cause serious collision problems. When o...

We examine the range of validity second-order cumulant expansion (CE) for calculation spectral functions, quasiparticle properties, and mobility Holstein polaron. devise an efficient numerical implementation that allows us to make comparisons in a broad interval temperature, electron-phonon coupling, phonon frequency. For benchmark, we use dynamical mean-field theory (DMFT) which gives, as have...

design and optimization of a single crystalline silicon (c-si) solar cell is performed to achieve the maximum light conversion efficiency. various parameters such as doping concentration and thicknesses, and geometrical dimension of surface pyramids are studied. the inverted surface pyramid is used to increase the efficiency of the solar cell, and engineered oxide layer is used as the passivati...