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Title:
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Soft weighted STTD for W-CDMA |
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Author:
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Hottinen, Ari; Wichman, Risto; Rajan, Dinesh
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Type:
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Conference Paper |
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Keywords:
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FDD mode; soft weighted STTD; W-CDMA; transmit antennas; space-time |
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Citation:
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A. Hottinen, R. Wichman and D. Rajan,"Soft weighted STTD for W-CDMA," in Allerton Conference on Communication, Control and Computing,, pp. 204-213. |
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Abstract:
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The transmit diversity concept adopted for teh FDD mode of the third generation WCDMA system in 3G standardization has an open-loop and a closed-loop mode. The open-loop mode applies a space-time block for two transmit antennas. The closed-loop mode has two sub-modes, which both utilize downloink measurements at terminal and subsequent feedback in controlling the phase and/or gain transmit weights in the transmit antennas in order to approximate matched beamforming. These concepts are summarized in this paper for two transmit antennas and they are compared to a soft-weighted transmit diversity concept, proposed here, in which the relative transmit powers of the space-time encoded signals are controlled by feedback signaling. This leasds to a robust feeback mode in which the terminal is simplified in the sense that it does not require dedicated reference/pilot symbols, or weight verification, as opposed to the current feedback modes. |
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Date Published:
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1999-09-20 |
