An efficient spectrum assignment for spatial division multiple access in millimeter wave cellular network

The use of millimeter-wave band is a promisq canddate for improvq performance of 5th generation mobile communication systems because of the vast amounts of available radio resources. However, in the veIy near future, data traffic is also expected to rapidly increase, due to the explosion of various multimeda services via. mobile communication. In this scenario, spectral efficiency enhancement will become impodant. In this study, a spectm utilization for spatial dvision multiple access is proposed. In the system, the base station uses beamforming antenna may to radiate signal in a pdcular direction to the desired user for the downlink. Reversely in uplmk, a beam is generated toward the desired user to receive the wanted signal as well as to reject the interference. As a resulf the base station can serve multiple users separately in the space domain. In this approach, the base station assigm the users whch do not interfere with each other in the same rado resource. On the other hand if users cannot be spatially separated they will be assigned the dsparate channels. The proposed scheme is expected to significantly enhance overall capacity of the network compared to the traditional schemes.