The Effect of Imperfect Phase Estimation on the Performance of MMSE Receiver Based CDMA Systems
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چکیده
This paper investigates the effect of phase offsets, due to inaccurate estimation of the desired user fading process, in the performance of minimum mean-squared error (MMSE) receiver-based direct-sequence (DS) codedivision multiple access (CDMA) systems in terms of bit error rate (BER). We compared the performance of QPSK and 16-QAM modulation formats with different system loads and phase offsets by derived theoretical bounds for BER. It is shown in this paper that multiuser interference and inaccurate phase estimation of the desired user fading are major factor in choosing the suitable modulation format. For the same channel bandwidth, 16-QAM is more successful in compacting multiuser interference while less successful in compacting the phase offsets due to inaccurate estimation of the desired user fading process.
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تاریخ انتشار 2003