摘要
In recent years,the demands of high traffic transmission motivate the rapid development of wireless access techniques,and it becomes promising to design the fifth generation(5G)wireless networks.Essential requirements for 5G involve higher traffic volume,indoor or hotspot traffic,and spectrum,energy,and cost efficien-
In recent years, the demands of high traffic trans- .mission motivate the rapid development of wirelessaccess techniques, and it becomes promising to design the fifth generation （5G） wireless networks. Essential re- quirements for 5G involve higher traffic volume, indoor or hotspot traffic, and spectrum, energy, and cost efficien- cy. So compared with the previous four generations, 5G will need to be a paradigm shift that includes very high carrier frequencies with massive bandwidths, extreme base station and device densities and unprecedented numbers of antennas.
