A comparative analysis of CABSINET/ACTS project uplink performance

CABSINET is an ACTS project focused on "last mile" cellular wireless access enabling delivery and use of interactive TV and broadband services. A two layer network (TLN) approach is adopted in the system proposal, the first layer (macrocell level) being devoted to the fixed reception, while the second layer (micro cells) is used for the portable application. The first layer is composed of adjacent macro-cells with a diameter in the order of 1 to 3 km. Each macrocell contains a central transmitter working in the 40 GHz band, and which is supposed to be in direct line of sight of the receiving antennas. The 40 GHz base station transmitters may be fed either by an optical fiber (B-ISDN network), or by a satellite link. The second layer is constituted by a series of broadband 5.8 GHz micro-cells with a diameter of a few hundred metres which fill a macrocell. In both layers the return link channel adopts a TDMA/CDMA combined approach as multiple access control (MAC). In this paper, the performance of the 5.8 GHz return channel is studied. In particular the capacity (number of users per cell) obtained with a classical RAKE receiver and a LMS-MMSE receiver is compared.