A novel multipath diversity scheme used in TDD-CDMA systems is presented. A
FIR filter is added in the transmitter, while a RAKE combiner is used in t
he receiver. The optimum FIR. filter problem may be used as an eigenvalue p
roblem. The multiple antennas system is also analyzed. Results show that th
is new scheme can greatly improve the output Signal to Noise Ratio (SNR) co
mpared with conventional RAKE receiver or Pre-RAKE diversity system.