• Journal of the Korea Society of Computer and Information
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• v.12 no.1 s.45
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• pp.145-154
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• 2007

In this paper, an improved detection method is proposed by supplementing various types of Multi-Path gam for a MMSE Multi-User detecter. This method is proposed to complement the shortcomings of the conventional detection method which is used for multiuser detection in STBC(Space-Time Block Code) CDMA system. We analyzed the improved method in bit error probability viewpoint and compared the result with that of the conventional method. In this result, we showed that the improved method obtains better performance of bit error probability than the conventional method when parameters such as delay, number of user and SNR are changed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.10A
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• pp.1540-1547
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• 2000

In this paper, the performance of the MMSE multiuser detector is compared with the conventional detector with respect to the signal-to-noise ratio, the number of users and the Nakagami parameter under AWGN as well as Nakagami fading channel. The results show that the MMSE multiuser detector is superior to the conventional detector with respect to cancelling the multiple access interference. However, its drawback is the hardware's complexity. To solve this drawback, the advanced MMSE multiuser detector is presented, and its performance is analyzed. The number of taps in the advanced MMSE multiuser are independent of the processing gain. Thus, the system engineer can choose the appropriate number of taps in the detector to achieve a optimal trade-off between the hardware complexity and the performance of system.

• Journal of the Korea Society of Computer and Information
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• v.9 no.2
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• pp.89-96
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• 2004

In this paper, an improved method is proposed by supplementing multi-path gain for detection. This method is proposed to complement the shortcomings of the conventional detection method which is used for multiuser detection in STBC(Space-Time Block Code) CDMA system. We analyzed the improved method in bit error probability viewpoint and compared the result with that of the conventional method. From this result, we showed that bit error probability of the improved method is superior to that of the conventional method when the parameters such as delay, number of user and SNR are increased.

• Journal of Communications and Networks
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• v.8 no.3
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• pp.290-296
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• 2006

In this paper, a generalized blind adaptive algorithm is introduced for multi-user detection of direct sequence code division multiple access (OS-COMA) wireless communication systems. The main property of the proposed algorithm is its ability to resolve the multipath fading channel resulting in inter symbol interference (ISI) as well as multiple access interference (MAI). Other remarkable properties are its low complexity and mitigation to the near-far problem as well as its insensitivity to asynchronous transmission. The proposed system is based on the minimization of the output energy and convergence to the minimum mean square error (MMSE) detector. It is blind in the sense that it needs no knowledge of the other users' signatures, only the intended user signature and timing are required. Furthermore, the convergence of the minimum output energy (MOE) detector to the MMSE detector is analytically proven in case of M-ary PSK. Depicted results show that the performance of the generalized system dominates those previously considered. Further improvements are obtained when multiple input multiple output (MIMO) technique is employed.

• Journal of the Korea Society of Computer and Information
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• v.10 no.2 s.34
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• pp.153-158
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• 2005

In this paper, an improved detection method is Proposed by supplementing multi-path gain for a MMSE detecter. This method is Proposed to complement the shortcomings of the conventional detection method which is used for multiuser detection in STBC CDMA system. We analyzed the improved method in bit error Probability viewpoint and compared the result with that of the conventional method In this result, we showed that the improved method obtains better performance of bit error probability than the conventional method when parameters such as delay, number of user and SNR are increased.