Capacity Enhancement by Using a Multi-User Detector on Uplink Synchronous Mode

The Uplink Synchronous Transmission\udScheme [1], is a technique used by operators, that exploit\udthe uplink orthogonality, to reduce multiple access\udinterferences in uplink direction and consequently to\udincrease uplink capacity. The USTS gives better\udperformances when we have an ideal case presented by\udno channelization code restrictions per scrambling code.\udIn reality, channelization codes are limited. To resolve\udthis problem, several scrambling codes are used to admit\udmore users in the cell. However, the use of different\udscrambling codes increases the multiple access\udinterference and consequently decreases uplink capacity\udgain, since signals transmitted by users under different\udscrambling codes are non-orthogonal. To obtain more\udperformances and therefore to increase the uplink\udcapacity gain, we will study the introduction of a multiuser\uddetector for interferences cancellation, in uplink\udsynchronous mode. For that, two values of interference\udcancellation efficiency\ud\udof the multi-user detector are\udconsidered. In this study, only the multiple access\udinterference is reduced. To show the effect of other-cell\udinterferences on uplink synchronous mode capacity, two\udscenarios are considered: an isolated cell and a multiple\udcell networ