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公开(公告)号：BR9903622A
公开(公告)日：2000-09-05
申请号：BR9903622
申请日：1999-08-12
Applicant: LUCENT TECHNOLOGIES INC
Inventor： GITLIN RICHARD DENNIS , MAILAENDER LAWRENCE EUGENE , VALENZUELA REINALDO A , HUANG HOWARD C
Abstract: A method and apparatus for increasing system capacity in a mixed-rate wireless communication are disclosed. Improvements are obtained using multiuser detection or antenna array processing techniques or both to explicitly cancel or attenuate only the high power users. Multiuser detection may be combined with antenna array processing to recover capacity appropriated by the high-power users. By mitigating the interference effects of only the high-powered users, the computational burden is manageable. An antenna array algorithm or a multiuser detection algorithm or both, are applied only to n high rate users (n
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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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公开(公告)号：CA2361886C
公开(公告)日：2011-07-26
申请号：CA2361886
申请日：2001-11-09
Applicant: LUCENT TECHNOLOGIES INC
Inventor： CHUNG SEONG-TAEK , HUANG HOWARD C , LOZANO ANGEL
IPC: H04L12/28 , H04W52/50 , H04B1/04 , H04B7/005 , H04B7/04 , H04B7/06 , H04L1/00 , H04L25/02 , H04W52/26 , H04W72/00
Abstract: In a wireless communication system using multiple antennas at the transmitter and multiple antennas at the receiver, a so called multiple-input multiple- output (MIMO) system, a substantial improvement in capacity over the case of no feedback can be achieved using considerably less bandwidth than is required to feedback the channel estimate or channel statistics, by supplying as feedback for each data substream of an overall data stream an indicator of a rate and/or an indicator of a gain for transmission of that data substream. The indicator of the rate and/or the indicator of the gain may be the rate and/or gain directly or an encoded representation of the rate and/or gain. Typically, the best performance is achieved if indicators of both the rate and the gain are fed back. If the invention is implemented for wireless systems, then typically for each data substream there is a separate, independent antenna. The rate and the gain are computed as a function of a channel estimate which is developed at the receiver. Advantageously, the transmitter may employ only one- dimensional data coding for each of the data substreams.
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公开(公告)号：DE69924197T2
公开(公告)日：2006-03-23
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 , 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：AU4245199A
公开(公告)日：2000-02-24
申请号：AU4245199
申请日：1999-08-03
Applicant: LUCENT TECHNOLOGIES INC
IPC: H04B1/10 , H04B1/7093 , H04B1/7103 , H04B1/7105 , H04B1/7115 , H04J13/04 , H04B7/216
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：BR9902616A
公开(公告)日：2000-01-18
申请号：BR9902616
申请日：1999-06-24
Applicant: LUCENT TECHNOLOGIES INC
Inventor： HUANG HOWARD C , MAILAENDER LAURENCE EUGENE
Abstract: A system, a transceiver, and methods for code division multiple access (CDMA) communication. The system includes first and second code division multiple access transceivers. The first code division multiple access transceiver has a plurality antennas disposed to provide transmission via a plurality of paths and the second code division multiple access transceiver has a rake arrangement for processing a plurality of signals received at the rake arrangement with differing delays or other characteristics. A driving arrangement is provided for causing the first code division multiple access transceiver to use a relative few, e.g., one, of the plurality of antennas. When, however, an indication is obtained that an adequate number of resolvable signals are likely not received at the rake arrangement of the second transceiver, a circuit switches the driving arrangement to cause the first transceiver to use more of the plurality of antennas. In one implementation, the second transceiver sends a feedback signal indicating the number of useful signals being received and the first transceiver responds to the feedback signal by selecting and using a desirable number of transmit antennas. In an implementation suitable for a time-division duplexing (TDD) communication system, the first transceiver obtains the indication by inference from the fact that it is not receiving an adequate plurality of resolvable signals from the second transceiver. When the first transceiver obtains the indication, it drives the increased number of antennas either with respective delays or with different codes of the CDMA type.
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公开(公告)号：DE69940183D1
公开(公告)日：2009-02-12
申请号：DE69940183
申请日：1999-06-23
Applicant: LUCENT TECHNOLOGIES INC
Inventor： HUANG HOWARD C , MAILAENDER LAURENCE EUGENE , VANNUCCI GIOVANNI
Abstract: A system, a transceiver, and methods for code division multiple access (CDMA) communication. The system includes first and second code division multiple access transceivers. The first code division multiple access transceiver has a plurality antennas disposed to provide transmission via a plurality of paths and the second code division multiple access transceiver has a rake arrangement for processing a plurality of signals received at the rake arrangement with differing delays or other characteristics. A driving arrangement is provided for causing the first code division multiple access transceiver to use a relative few, e.g., one, of the plurality of antennas. When, however, an indication is obtained that an adequate number of resolvable signals are likely not received at the rake arrangement of the second transceiver, a circuit switches the driving arrangement to cause the first transceiver to use more of the plurality of antennas. In one implementation, the second transceiver sends a feedback signal indicating the number of useful signals being received and the first transceiver responds to the feedback signal by selecting and using a desirable number of transmit antennas. In an implementation suitable for a time-division duplexing (TDD) communication system, the first transceiver obtains the indication by inference from the fact that it is not receiving an adequate plurality of resolvable signals from the second transceiver. When the first transceiver obtains the indication, it drives the increased number of antennas either with respective delays or with different codes of the CDMA type.
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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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19.发明专利
公开(公告)号：CA2308902C
公开(公告)日：2003-12-02
申请号：CA2308902
申请日：2000-05-19
Applicant: LUCENT TECHNOLOGIES INC
Abstract: Multiple microcell base stations are located within a macrocell having a single macrocell base station in an hierarchical architecture, and microcell users (.mu.-users) and macrocell users (M-users) communicate respectively with the .mu.-base and the M-base using the same frequency band, by appropriately (a) selecting the ratio of the radius r of each .mu. cell and the average distance d from the M-base (r and d are measured by the "radio distance", which includes the effects of shadowing), and (b) controlling the power level with which uplink (mobile to base) and downlink (base to mobile) messages are communicated. Typically, .mu.-cell size and location are chosen such that d/r > 10. With respect to uplink communications, the transmit powers of the .mu. -users in a .mu.-cell are controlled so that the total received power at the nearest M-base is equivalent to the received power from C M-users, where C is usually set to unity. As a result, the M-cell basically loses C users worth of capacity, but the total number of users is increased by virtue of the additional .mu.-users. With respect to downlink communications, as long as the microbase and the macrobase are coordinated systems, the .mu.-base transmit power is controlled so that at the point of handoff between a .mu.-base and M-base,the received power at a user from the two bases is equivalent, and the received power at the bases from this user is also equivalent. With this arrangement, the .mu.-base transmit power is increased as r grows and d decreases in order for this balance to occur. Where the M-base and .mu.-base have no knowledge of each other and handoffs are not allowed between the two base types, a family of I/Q short codes which are quasi-orthogonal to the existing short (pilot) codes are generated, and these codes are used to distinguish between the M-base and .mu.-base signals.
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20.发明专利
公开(公告)号：CA2308902A1
公开(公告)日：2000-11-28
申请号：CA2308902
申请日：2000-05-19
Applicant: LUCENT TECHNOLOGIES INC
Abstract: Multiple microcell base stations are located within a macrocell having a single macrocell base station in an hierarchical architecture, and microcell users (.mu.-users) and macrocell users (M-users) communicate respectively with the .mu.-base and the M-base using the same frequency band, by appropriately (a) selecting the ratio of the radius r of each .mu. cell and the average distance d from the M-base (r and d are measured by the "radio distance", which includes the effects of shadowing), and (b) controlling the power level with which uplink (mobile to base) and downlink (base to mobile) messages are communicated. Typically, .mu.-cell size and location are chosen such that d/r > 10. With respect to uplink communications, the transmit powers of the .mu. -users in a .mu.-cell are controlled so that the total received power at the nearest M-base is equivalent to the received power from C M-users, where C is usually set to unity. As a result, the M-cell basically loses C users worth of capacity, but the total number of users is increased by virtue of the additional .mu.-users. With respect to downlink communications, as long as the microbase and the macrobase are coordinated systems, the .mu.-base transmit power is controlled so that at the point of handoff between a .mu.-base and M-base, the received power at a user from the two bases is equivalent, and the received power at the bases from this user is also equivalent. With this arrangement, the .mu.-base transmit power is increased as r grows and d decreases in order for this balance to occur. Where the M-base and .mu.-base have no knowledge of each other and handoffs are not allowed between the two base types, a family of I/Q short codes which are quasi-orthogonal to the existing short (pilot) codes are generated, and these codes are used to distinguish between the M-base and .mu.-base signals.
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