Simulation of uplink and downlink macrodiversity schemes in a cellular network

Mobile radio communications experience multiple impairments due to various effects (masks, multipath fading, interferences, ...). Bit error rate (BER) values on a radio link are often greater or equal to 10/sup -4/ (against less than 10/sup -8/ on fixed links). Numerous methods are designed in order to reduce or to overcome these radio problems: coding, equalisation, etc. In this paper, we focus on the diversity methods and more precisely on the macrodiversity schemes. These consist in maintaining several communication links (physical or logical links) between a mobile station and the fixed network. Macrodiversity techniques should allow, apart from keeping the communication quality over a certain threshold (especially during a handover), to minimize the global radio spectrum usage. Several macrodiversity techniques have already been investigated in the literature. We have simulated some of them in an urban high traffic density mobile radio cellular environment. The mobile radio channel model used in this paper takes into account mask and multipath effects attenuations.