System for reducing co-channel interference in cellular mobile radio networks with adjacent radio areas of extremely differing sizes

摘要

In mobile radio systems with cellular radio area division, direct adjacency of radio areas of extremely differing sizes may occur, typically in peripheral zones of built-up areas. If the known seven-frequency distribution plan (honeycomb structure) is taken as a basis, this frequency distribution can no longer be sustained in peripheral zones since the smaller radio areas are so physically close to substantially more powerful transmitters of the large radio areas that co-channel interference in the smaller radio areas assumes unacceptable proportions. It is proposed to implement the radio coverage of large radio areas which are directly adjacent to small radio areas not by means of centrally located radio concentrators with omnidirectional antennas, but to have these areas jointly supplied with the aid of sector antennas which are allocated to the radio concentrators of the small adjacent areas. IMAGE