Antenna Sectorization and Macrodiversity in CDPA Wireless Systems

Piazza leonardo Da Vinci, 32 20133 Milano, ITALY fax: +39-2-2399-3413; e-mail: last [email protected] Abstract— Recently, a new method for achieving spectrum reuse in cellular systems, called Capture-Division Packetized Access (CDPA), has been introduced. The method uses a single frequency in all cells, and uses packet switching and packet retransmission as a means to overcome destructive cochannel interference. Since it uses bandwidth only when needed, this technique can present better throughput performance than techniques that use frequency reuse or channel coding to protect against interference. In this paper we analyze two variations of CDPA that apply when the antenna coverage is reduced to 120 degrees. Both variations provide at least three times as much throughput as the basic CDPA, that operates with omnidirectional antennas. Furthermore, one of these variations presents intrinsic macrodiversity, which often allows to overcome the shadowing problem without resorting to handover. The shadowing issue is discussed and the robustness of the technique is evaluated.