Multiple pre-Rake filtering based on the predicted channel impulse response in the transmitter and a Rake combiner in the receiver for TDD/DS-CDMA mobile communication systems

Chang Jun Ahn, Iwao Sasase

Research output: Contribution to journalArticle

2 Citations (Scopus)


The pre-Rake system is known as a technique in TDD DS/CDMA system to reduce the mobile complexity and achieve the same BER performance like Rake receiver. The pre-Rake system itself is not optimum, since the channel impulse responses of uplink and downlink are slightly different in TDD system, so the signal-to-noise ratio (SNR) can be maximized with a matched filter based Rake receiver, which has not been considered in the conventional pre-Rake system. Furthermore pre-Rake system is sensitive to the Doppler frequency. Even though the pre-Rake system has the ability to suppress other user interference, it is not efficient to maximize the received signal in high Doppler frequency. However, Rake combiner is utilized for the detection method in our proposed system. So the maximized signal can keep the orthogonality better than the pre-Rake system and our proposed system can compensate the Doppler frequency effect. From these reasons, our system achieves better BER performance than that of the pre-Rake system which increasing the number of users in high Doppler frequency.

Original languageEnglish
Pages (from-to)2282-2291
Number of pages10
JournalIEICE Transactions on Communications
Issue number10
Publication statusPublished - 2002 Oct



  • CDMA
  • Pre-Rake system
  • Rake receiver
  • Time division duplex (TDD)

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Computer Networks and Communications

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