Device for joint detection of cdma codes for multipath downlink

摘要

A conjoint detection device for UMTS/TDD mobile radio telephone terminal receiver processes a received signal having symbols coded in accordance with K CDMA codes and having passed through a propagation channel with Lt multiple paths. The device has two channels each imposing Lt/2 respective delays and each having K filtering branches. Each filtering branch correlates Lt/2 delayed sample sequences to a respective code and to Lt/2 estimated path coefficients in order to sum Lt/2 coefficients correlated in this way sampled at the symbol period. 2K equalization filters then equalize linearly the 2K correlated signals, depending on an associated code, before they are summed at the output of the two channels. Thanks to the division into two channels, there are sufficient degrees of freedom to cancel the interference out exactly for a finite depth of the 2K equalization filters greater than twice the duration of the propagation channel.