Reducing frequency reuse distance in cellular communications using trelliscoded modulation

Co-channel interference is of great concern when planning modern cellular c ommunication systems, The commonly used seven-cell frequency reuse pattern is based on the fact that the carrier to interference ratio (C/I) should be higher than 18dB, which is based on subjective tests (W.C.Y. Lee, 1995). A scheme based on trellis coded modulation (TCM) is proposed which enables t he system to perform satisfactorily even at reduced levels of C/I The propo sed scheme gives the flexibility to use four or three cell repeat patterns, thus substantially increasing the spectral efficiency of the system. The s cheme proposes the use of different TCMs in the different co-channel cells. Simulation results have shown that for a four-cell repeat pattern the prop osed scheme resulted in a bit error rate of 10(-5) or better, with an outag e probability of 0.86%.