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公开(公告)号：JP2001016185A
公开(公告)日：2001-01-19
申请号：JP2000166157
申请日：2000-06-02
Applicant: LUCENT TECHNOLOGIES INC
Abstract: PROBLEM TO BE SOLVED: To reduce all interference between wireless terminals by allocating codes to plural wireless terminals based on decided plural channel characteristics. SOLUTION: A combined signal is transmitted to a simultaneous channel estimator 114 and a space-time matched filter 116. The simultaneous channel estimator 114 receives a base band signal and decides characteristics κpk of a wireless channel where the signal is received. A base station 102 has a code optimizer 118 for allocating a code to a wireless terminal. A processing set is initialized with respect to one of the wireless terminals. A target wireless terminal is selected from the processing set. When there is only one wireless terminal in the processing set, the wireless terminal is selected as the target wireless terminal. Regarding the wireless terminal selected as the target, random code search is executed.
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公开(公告)号：JP2000209137A
公开(公告)日：2000-07-28
申请号：JP36813499
申请日：1999-12-24
Applicant: LUCENT TECHNOLOGIES INC
Abstract: PROBLEM TO BE SOLVED: To achieve diversity merits without receiving demerits so much by transmitting respective data symbol sets to the respective users of a user group by the form plural mutually different signal sequences which are the linear connection of spreading code sequences belonging to a corresponding code group. SOLUTION: An antenna 1 (25.1) transmits signals (1/21/2) (b1c1+b2c2) and the antenna 2 (25.2) transmits the signals (1/21/2) (b2c1-b1c2). In such a manner, while only two pieces of spreading codes are used, the two codes are used for a data symbol to the user (20.1) and also the two codes are used for the data symbol to the user (20.2) as well. Thus, at the time of using plural transmitter antennas, a system for sufficiently achieving the diversity merits without receiving the demerits in the number of the codes required to be allocated per user so much, is realized.
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公开(公告)号：JP2002009735A
公开(公告)日：2002-01-11
申请号：JP2001138083
申请日：2001-05-09
Applicant: LUCENT TECHNOLOGIES INC
Inventor： LI XIADONG , PAPADIAS CONSTANTINOS BASIL , VISWANATHAN HARISH
Abstract: PROBLEM TO BE SOLVED: To provide an orthogonal frequency division multiplexing transmission diversity system that can be used for a frequency selective fading channel in wireless communication. SOLUTION: A control system selector 205 supplies a signal Y0 to an even OFDM interval and a signal Y'1 in an odd number OFDM interval as an output supplied to a cyclic prefix unit 209 under the control of a selection input 217. The cyclic prefix unit 209 has a cyclic prefix prepositioned to each OFDM interval, that is each symbol period. A digital/analog converter 210 converts the signals Y0, Y'1 into analog signals, which are fed to an RF transmitter 211 for the transmission through an antenna 212, that is an antenna 0.
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公开(公告)号：JP2000115028A
公开(公告)日：2000-04-21
申请号：JP22036999
申请日：1999-08-03
Applicant: LUCENT TECHNOLOGIES INC
IPC: H04B1/10 , H04B1/7093 , H04B1/7103 , H04B1/7105 , H04B1/7115 , H04B1/707 , H04J13/04
Abstract: PROBLEM TO BE SOLVED: To improve detector performance and also increase a system capacity by using an adaptive detector by means of considering unknown interference. SOLUTION: A linear coupler is used and multi-access interference is considered in a multi-user space time rake receiver. A real part operator is used before the linear coupler in the first version of the detector. In this case, a linear coupler processor 20 comprises the bank of the real part operator and the linear coupler after it and respective components 1411-14K are slicers for judging an estimation symbol being most close to the input. An unknown interference source is considered in this way so that detector performance is improved and also the system capacity is increased. For example, interference from an buried micro-cell can be considered in a base station receiver. In the meantime, interference from a signal which is not demodulated can be considered in a hand-set receiver.
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公开(公告)号：CA2279471A1
公开(公告)日：2000-02-04
申请号：CA2279471
申请日：1999-07-30
Applicant: LUCENT TECHNOLOGIES INC
IPC: H04B1/10 , H04B1/7093 , H04B1/7103 , H04B1/7105 , H04B1/7115 , H04B1/707 , H04B1/16
Abstract: Linear space-time multiuser detectors are described that combine array processing, rake detection, and multiuser detection and that satisfy a minimum mean-squared error criteria. Both embodiments can be implemented adaptively so as to account for unknown sources of interference. The adaptive implementation of the first embodiment of a linear space-time detector requires explicit estimates of the channel coefficients. On the other hand, the adaptive implementation of the second embodiment does not require these estimates since they can be adaptively obtained. Both of these detectors provide significant performance advantages over single-user space-time detectors and over multiuser detectors which do not account for CDMA interference from unknown sources.
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Patent Agency Ranking
公开(公告)号：DE69924197D1
公开(公告)日：2005-04-21
申请号：DE69924197
申请日：1999-07-26
Applicant: LUCENT TECHNOLOGIES INC
IPC: H04B1/10 , H04B1/7093 , H04B1/7103 , H04B1/7105 , H04B1/7115 , H04B1/707 , H04B7/08
Abstract: Linear space-time multiuser detectors are described that combine array processing, rake detection, and multiuser detection and that satisfy a minimum mean-squared error criteria. Both embodiments can be implemented adaptively so as to account for unknown sources of interference. The adaptive implementation of the first embodiment of a linear space-time detector requires explicit estimates of the channel coefficients. On the other hand, the adaptive implementation of the second embodiment does not require these estimates since they can be adaptively obtained. Both of these detectors provide significant performance advantages over single-user space-time detectors and over multiuser detectors which do not account for CDMA interference from unknown sources.
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公开(公告)号：DE60008040D1
公开(公告)日：2004-03-11
申请号：DE60008040
申请日：2000-05-23
Applicant: LUCENT TECHNOLOGIES INC
Abstract: A CDMA wireless communication system for communicating with wireless terminals (110) comprises a channel estimator (114) for determining characteristics of the wireless channels of the wireless terminals. The channel characteristics are used by a code optimizer (118) to assign spreading codes to the wireless terminals. In one embodiment, the code optimizer utilizes an iterative code optimization algorithm and maintains a processing set of wireless terminals. The code optimizer (118) chooses target wireless terminals and performs a random code search in order to find an improved code for the target wireless terminal. The improved code found in the random code search is further improved by performing a gradient search of codes in the signal space in the vicinity of the improved code and by performing a gradient search of transmission delays. The improved codes are transmitted to the wireless terminals (110) for use in reverse link communication.
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公开(公告)号：CA2279471C
公开(公告)日：2004-03-02
申请号：CA2279471
申请日：1999-07-30
Applicant: LUCENT TECHNOLOGIES INC
IPC: H04B1/10 , H04B1/7093 , H04B1/7103 , H04B1/7105 , H04B1/7115 , H04B1/707 , H04B1/16
Abstract: Linear space-time multiuser detectors are described that combine array processing, rake detection, and multiuser detection and that satisfy a minim um mean-squared error criteria. Both embodiments can be implemented adaptively so as to account for unknown sources of interference. The adaptive implementation of the firs t embodiment of a linear space-time detector requires explicit estimates of the channel coefficients. On the other hand, the adaptive implementation of the second embodiment does no t require these estimates since they can be adaptively obtained. Both of these detecto rs provide significant performance advantages over single-user space-time detectors and over multiuser detectors which do not account for CDMA interference from unknown sources.
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公开(公告)号：BR0002525A
公开(公告)日：2001-03-13
申请号：BR0002525
申请日：2000-05-30
Applicant: LUCENT TECHNOLOGIES INC
Abstract: A CDMA wireless communication system for communicating with wireless terminals (110) comprises a channel estimator (114) for determining characteristics of the wireless channels of the wireless terminals. The channel characteristics are used by a code optimizer (118) to assign spreading codes to the wireless terminals. In one embodiment, the code optimizer utilizes an iterative code optimization algorithm and maintains a processing set of wireless terminals. The code optimizer (118) chooses target wireless terminals and performs a random code search in order to find an improved code for the target wireless terminal. The improved code found in the random code search is further improved by performing a gradient search of codes in the signal space in the vicinity of the improved code and by performing a gradient search of transmission delays. The improved codes are transmitted to the wireless terminals (110) for use in reverse link communication.
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公开(公告)号：CA2310175A1
公开(公告)日：2000-12-04
申请号：CA2310175
申请日：2000-05-29
Applicant: LUCENT TECHNOLOGIES INC
Abstract: A CDMA wireless communication system for communicating with wireless terminals. The system comprises a channel estimator for determining characteristics of the wireless channels of the wireless terminals. The channel characteristics are used by a code optimizer to assign spreading codes to the wireless terminals. In one embodiment, the code optimizer utilizes an iterative code optimization algorithm and maintains a processing set of wireless terminals. The code optimizer chooses target wireless terminals and performs a random code search in order to find an improved code for the target wireless terminal. The improved code found in the random code search is further improved by performing a gradient search of codes in the signal space in the vicinity of the improved code and by performing a gradient search of transmission delays. The improved codes are transmitted to the wireless terminals for use in reverse link communication.
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