A study of wireless access networks architecture using multi-level modulation methods

A new type of wireless access network architecture using the 5 GHz frequency band is proposed. In the proposed network, several multi-level modulation methods such as QPSK, 16 QAM and 256 QAM are combined and applied to the access links in order to efficiently enlarge the system capacity within the 5 GHz frequency band. The accommodation number of user terminals and the width of the service area are theoretically analyzed considering the antenna directivity and the reuse number of identical frequency. Some numerical results show that the proposed architecture can obtain about 240 terminals improvement in the accommodation of user terminals and about 20% improvement in the radius of service area compared with conventional architecture where only the QPSK method is used.