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公开(公告)号：JP2000138652A
公开(公告)日：2000-05-16
申请号：JP23191699
申请日：1999-08-18
Applicant: LUCENT TECHNOLOGIES INC
Inventor： GITLIN RICHARD DENNIS , HUANG HOWARD C , MAILAENDER LAURENCE EUGENE , VALENZUELA REINALDO A
Abstract: PROBLEM TO BE SOLVED: To efficiently increase a system capacity by identifying a high-rate user and reducing the influence of interference only for the high-rate user. SOLUTION: A receiver 400 efficiently gets back a capacity occupied by n-number of high power users by combining an antenna array algorithm 430 and a multi-user detecting algorithm 420. Signals from k-number of users in all are received by antennas 410 to 411. Among the k-number of users, n-number of (k>n) users are the high-rate users and the other (k-n) users are low-rate users. An antenna array algorithm 430, a multi-user detecting algorithm 420 or both of them are applied to only the high-rate users. Namely, concerning the algorithm 430, only ones corresponding to the high-rate user among θ1 to θn are made null and concerning a multi user detecting algorithm 420, only ones corresponding to the high-rate user among signature sequences s1 to sn are utilized.
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公开(公告)号：JPH10327126A
公开(公告)日：1998-12-08
申请号：JP11641298
申请日：1998-04-27
Applicant: LUCENT TECHNOLOGIES INC
Inventor： HUANG HOWARD C , CHIH-LIN I , TEN BRINK STEPHAN , VANNUCCI GIOVANNI
Abstract: PROBLEM TO BE SOLVED: To improve performance by preventing interference to a multipath caused by a pilot signal by removing the pilot signal of multipath component, which causes the interference of base band received signal, by reconstituting it as prescribed and adding/subtracting that signal later. SOLUTION: A signal r0 of path 0 and a signal r1 of path 1 in received decoding signals r(n) are respectively processed by an on-time selector circuit OTS and inputted to RAKE fingers 603 and 604 later. In this case, pilot reconstitution circuits 606 and 607 are reconstituting pilot signals through predicted attenuation, phase and path delay are respectively added to the fingers 603 and 604, the pilot signal from the path 0 is reconstituted, subtracted from the signal of path 1 by an adder 609 and removed. Similarly, the pilot signal reconstituted from the path 1 is subtracted from the signal of path 0 by an adder circuit 608 and removed and afterwards, the signals are respectively exactly demodulated by fingers 0 and 1 and bit-determined or processed by a viterbi decoder 605.
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公开(公告)号：JP2003110474A
公开(公告)日：2003-04-11
申请号：JP2002242781
申请日：2002-08-23
Applicant: LUCENT TECHNOLOGIES INC
Inventor： HUANG HOWARD C , MAILAENDER LAURENCE EUGENE , SANDELL MAGNUS , VISWANATHAN HARISH
IPC: H04J99/00 , H04B1/707 , H04B7/005 , H04B7/06 , H04B7/08 , H04L1/06 , H04L25/02 , H04L25/03 , H04J15/00
Abstract: PROBLEM TO BE SOLVED: To provide a joint minimum average square error (MMSE) equalizer used for reducing a bit error rate floor that is generated by the dispersion of time in an MIMO system for all combinations of each transmission antenna/ reception antenna that are enabled in the MIMO system. SOLUTION: Resultant joint equalization corrects not only the influence of a channel where a transmission antenna and a reception antenna are combined but also the interference of other transmission antennas to any given reception antennas. The joint equalization shows improved performance as compared with simple reproduction of the minimum average square error (MMSE) equalizer in the conventional technique to the combination of each transmission antenna/reception antenna.
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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：JP2002217752A
公开(公告)日：2002-08-02
申请号：JP2001349252
申请日：2001-11-14
Applicant: LUCENT TECHNOLOGIES INC
Inventor： CHUNG SEONG-TAEK , HUANG HOWARD C , LOZANO ANGEL
Abstract: PROBLEM TO BE SOLVED: To attain a substantial improvement in capacity over the case of no feedback by using considerably less bandwidth than is required to feedback the channel estimate or channel statistics in a MIMO(multiple-input multiple- output) system. SOLUTION: An indicator of a rate and/or an indicator of a gain for transmission of a data substream are supplied as feedback for each data substream of an overall data stream. 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. The best performance is achieved if indicators of both the rate and the gain are fed back. The rate and the gain are computed as a function of a channel estimate which is developed at the receiver. The transmitter may employ only one-dimensional data coding for each of the data substreams.
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Patent Agency Ranking
公开(公告)号：JP2002141865A
公开(公告)日：2002-05-17
申请号：JP2001266662
申请日：2001-09-04
Applicant: LUCENT TECHNOLOGIES INC
Inventor： HUANG HOWARD C , KOGIANTIS ACHILLES GEORGE , HARISH BISUWANASAN
Abstract: PROBLEM TO BE SOLVED: To provide a high quality communication system. SOLUTION: In the radio communication system using plural antennas for transmission, a method is provided for easily distinguishing pilot signals (carrier signals) transmitted from the different antennas. As one example, each of two antennas simultaneously transmits the value of a time slot in data while multiplexing the pilot signal with the data in the time division manner. A pilot signal from the first antenna of two antennas is encoded by a first code like a Walsh code and a pilot signal from the second antenna is encoded by a second code like the other Walsh code. By means of such different codes, a receiver can perform the coherent detection of signals transmitted by both the first and second antennas.
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公开(公告)号：JPH10322312A
公开(公告)日：1998-12-04
申请号：JP11854198
申请日：1998-04-28
Applicant: LUCENT TECHNOLOGIES INC
Inventor： HUANG HOWARD C , CHIH-LIN I
IPC: H04B1/709 , H04B1/7105 , H04B1/7107 , H04B1/7115 , H04B7/26 , H04L7/00 , H04J13/04
Abstract: PROBLEM TO BE SOLVED: To provide a receiver using a pilot interference removal device by permitting an MC-CDMA receiver to receive a complex amplitude modulation replica delayed by the time of a transmitted CDMA signal, forming a multi-path delay prediction value, demodulating a multi-path component, combining results, controlling interference caused by other data and generating a desired demodulation data signal. SOLUTION: This MC-CDMA receiver 103 having a partial de-correlator receives a multi-path coherent radio frequency signal through an antenna 121. Multi-path signals are down-converted by modulators 122 and 123 by using the radio frequency signals. The outputs of the modulators 122 and 123 are filter-processed by anti-aliasing low pass filters LPF 124 and 125, and the I signal and the Q signal of the base band are generated. They, are processed by an MC-CDMA rake receiver 128 and a digital signal processor DSP 129 and an output data signal 130 is generated.
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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：CA2377539A1
公开(公告)日：2001-01-04
申请号：CA2377539
申请日：2000-06-16
Applicant: LUCENT TECHNOLOGIES INC
Inventor： FOSCHINI GERARD JOSEPH , VISWANATHAN HARISH , HUANG HOWARD C
Abstract: High-speed wireless data systems and methods are described for simultaneousl y supporting multiple data users, including flexible mixed-traffic services, using an illustrative CDMA architecture. Embodiments are compatible with current and third generation CDMA systems, while achieving spectral efficiencies that are in some cases an order of magnitude or more higher. Embodiments advantageously employ multiple antennas at the transmitter and receiver and code spreading to realize multiple access systems. Some illustrative receiver embodiments advantageously employ a decorrelating detector, while other features a decorrelating decision-feedback detector. I n typical operation, each of a plurality of high-speed data streams directed t o respective data users is demultiplexed into multiple (G~1) lower rate substreams, which are modulated by a CDMA spreading code and transmitted fro m Mantennas at a base station. A receiver employs Pantennas and multi-user detection to demodulate the Gdata substreams of its associated user. Performance measures for a variety of illustrative transmission and receiver configurations are derived using novel techniques for calculating system level capacities and spectral efficiencies (measured in bits per second per Hertz per sector). System design and configuration tradeoffs are readily made based on such performance determinations.
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公开(公告)号：CA2361886A1
公开(公告)日：2002-05-16
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 , H04B1/04 , H04B7/005 , H04B7/06 , H04L1/00 , H04L25/02 , H04W52/26 , H04W52/50 , H04B7/04 , H04L5/14 , H04Q7/36
Abstract: In a wireless communication system using multiple antennas at the transmitt er 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 feedba ck the channel estimate or channel statistics, by supplying as feedback for each da ta substream of an overall data stream an indicator of a rate and/or an indicat or of a gain for transmission of that data substream. The indicator of the rate and/or th e indicator of the gain may be the rate and/or gain directly or an encoded representatio n 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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