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公开(公告)号：CA2313253A1
公开(公告)日：2001-01-15
申请号：CA2313253
申请日：2000-06-29
Applicant: LUCENT TECHNOLOGIES INC
Inventor： WU I-FONG ANTONIO , YU BEE YUN , HUANG CHING YAO , HUANG JOE , WU XIAO CHENG
Abstract: Soft handoffs in an IS-95 CDMA system or other wireless communication syst em are controlled using an enhanced set of soft handoff parameters which allow the system to adapt more readily to changing radio frequency (RF) conditions. In an illustrative embodiment, values for particular ones of the soft handoff parameters are selected in accordance with a set of rules, including rules such as, e.g., select the minimum value of add threshold among the members of an active set of pilots for a given mobile station; select the maximum value of drop threshold among the members of the active set; select the minimum value of drop threshold timer among the members of the active set; and selec t the minimum value of comparison threshold among the members of the active set. A quality measure is then determined for each of the members of the active set, based on one or more of the selected soft handoff parameter values and values of one or more additional parameters, e.g., add intercept, drop intercept and slope parameters, associated with those members. Particular values of the additional parameters are then selected based on th e quality measures. The selected parameter values are then utilized in a soft handoff process, e.g., in a soft handoff process in which the given mobile station is directed to handoff from a primary base station to another base station of the system.
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公开(公告)号：ID25748A
公开(公告)日：2000-11-02
申请号：ID991040
申请日：1999-11-11
Applicant: LUCENT TECHNOLOGIES INC
Inventor： MEYERS MARTIN HOWARD , NALLEPILI S RAMESH , WANG JIAN-REN , WU XIAO CHENG
Abstract: Disclosed is a method for significantly reducing the amount of collisions of access messages on reverse link Random Access Channels (RACH) by multiple mobile-stations attempting to gain system access concurrently, thereby greatly improving access performance in wireless communications system using existing multiple access schemes. The improvement is achieved by transmitting a probe message instead of an access message over the RACH, wherein the probe message is shorter in length than the access message. Transmission of the probe messages utilizes less of the RACH than the longer access messages, thereby reducing the chance of collisions with other probe messages. The access message is subsequently sent on a traffic channel or a control channel designated by a base station receiving the probe message. Alternately, a data burst is transmitted over the designated traffic channel or control channel.
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公开(公告)号：BR9904034A
公开(公告)日：2000-09-12
申请号：BR9904034
申请日：1999-09-02
Applicant: LUCENT TECHNOLOGIES INC
Inventor： BERNSTEIN NEIL E , WU XIAO CHENG
Abstract: A method and system that minimizes pilot signal overlap and radio frequency ("RF") interference by estimating changes in pilot coverage for different traffic channel loading and power conditions. Once base stations are positioned, a terminal for measuring received pilot signal strengths, such as a mobile station or pilot scanner, is used to collect and generate the baseline pilot survey data, which is then stored on a disk or tape. Base station transmit pilot EC/IOs, i.e., traffic channel loads on forward links, are also stored on disk or tape. The invention uses two adjustment factors associated with transmit power and traffic channel loading to optimize for different RF conditions, specifically for different base station transmit power or forward link loading conditions. For each RF condition, the methodology calculates the changes in the baseline pilot survey data. This reflects what EC/IOs a mobile station would receive under the given conditions. The systems engineer collects a set of optimized base station power settings for each of the different traffic channel load conditions. One of these optimized power settings is then selected by the systems engineer for each of the base stations.
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公开(公告)号：CA2279626A1
公开(公告)日：2000-03-08
申请号：CA2279626
申请日：1999-08-04
Applicant: LUCENT TECHNOLOGIES INC
Inventor： WU XIAO CHENG , BERNSTEIN NEIL E
Abstract: A method and system that minimizes pilot signal overlap and radio frequency ("RF") interference by estimating changes in pilot coverage for different traffic channel loading and ower conditions. Once base stations are positioned, a terminal for measuring received pilot signal strengths, such as a mobile station or pilot scanner, is used to collect and generate the baseline pilot survey data, which is then stored on a disk or tape. Base station transmit pilot Ec/I o s, i.e., traffic channel loads on forward links, are also stored on disk or tape. The invention uses two adjustment factors associated with transmit power and traffic channel loading to optimize for different RF conditions, specifically for different base station transmit power or forward link loading conditions. For each RF condition, the methodology calculates the changes in the baseline pilot survey data. This reflects what Ec/I o s a mobile station would receive under the given conditions. The systems engineer collects a set of optimized base station power settings for each of the different traffic channel load conditions. One of these optimized power settings is then selected by the systems engineer for each of the base stations.
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公开(公告)号：BR9901113A
公开(公告)日：2000-01-11
申请号：BR9901113
申请日：1999-03-19
Applicant: LUCENT TECHNOLOGIES INC
Inventor： BERNSTEIN NEIL E , KUO WEN-YI , MEYERS MARTIN HOWARD , WANG XIAO , WEAVER CARL FRANCIS , WU XIAO CHENG
Abstract: Inter-frequency handoffs in a CDMA or other wireless communication system are controlled using a noise-limited coverage trigger metric which is able to distinguish between same-frequency cell boundaries and other-frequency cell boundaries in the system. The trigger metric may be generated as a function of an average signal-to-noise measure for pilot signals received at a mobile station of the system and a linear sum of the signal-to-noise measures. The signal-to-noise measures may be generated in the mobile station and included in messages transmitted from the mobile station to one or more base stations of the system. The trigger metric is used to control a handoff from a current frequency to a new frequency in an ongoing call. The trigger metric may alternatively be based on a measure of mobile receive power alone. Other aspects of the invention reduce unnecessary searching for a new frequency and decrease the likelihood of "ping-ponging" from a current frequency to a new frequency by providing additional checks in the handoff process. For example, receive power and pilot signal-to-noise measures may be generated at a mobile station for both current and new frequencies. The mobile station then continues to operate at the current frequency as long as certain predetermined threshold conditions based on the measures are satisfied.
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Patent Agency Ranking
公开(公告)号：DE60026457T2
公开(公告)日：2006-09-14
申请号：DE60026457
申请日：2000-07-03
Applicant: LUCENT TECHNOLOGIES INC
Inventor： HUANG CHING YAO , HUANG JOE , WU I-FONG ANTONIO , WU XIAO CHENG , YU BEE YUN
Abstract: Soft handoffs in an IS-95 CDMA system or other wireless communication system are controlled using an enhanced set of soft handoff parameters which allow the system to adapt more readily to changing radio frequency (RF) conditions. In an illustrative embodiment, values for particular ones of the soft handoff parameters are selected in accordance with a set of rules, including rules such as, e.g., select the minimum value of add threshold among the members of an active set of pilots for a given mobile station; select the maximum value of drop threshold among the members of the active set; select the minimum value of drop threshold timer among the members of the active set; and select the minimum value of comparison threshold among the members of the active set. A quality measure is then determined for each of the members of the active set, based on one or more of the selected soft handoff parameter values and values of one or more additional parameters, e.g., add intercept, drop intercept and slope parameters, associated with those members. Particular values of the additional parameters are then selected based on the quality measures. The selected parameter values are then utilized in a soft handoff process, e.g., in a soft handoff process in which the given mobile station is directed to handoff from a primary base station to another base station of the system.
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公开(公告)号：DE69923927T2
公开(公告)日：2005-12-29
申请号：DE69923927
申请日：1999-12-07
Applicant: LUCENT TECHNOLOGIES INC
Inventor： KUO WEN-YI , MEYERS MARTIN HOWARD , WU XIAO CHENG
Abstract: The present invention is a method for efficiently utilizing spectrum resources belonging to a wireless communications system in the presence of data channels through a discontinuous data transmission technique. The discontinuous data transmission technique involves the transmission of a flag over a control channel (or some other communication channel) in frame f, wherein the flag would indicate to an intended recipient that a transmitter has a data frame to transmit to the recipient in some future frame f+q. In an embodiment, the transmitter would subsequently transmit the data frame over a data channel (or some other communication channel) in frame f+q if the flag indicated that the data frame was ready to be transmitted. In another embodiment, the transmitter would not transmit the data frame unless the recipient has indicated (via another flag) that the recipient is ready to receive the frame of data from the transmitter.
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公开(公告)号：CA2313555C
公开(公告)日：2004-04-20
申请号：CA2313555
申请日：2000-07-06
Applicant: LUCENT TECHNOLOGIES INC
Inventor： WU XIAO CHENG , WEAVER CARL FRANCIS
Abstract: Base station in a soft handoff programmed to have a threshold power level to control the power transmitted by the base station on the forward link. When the threshold power level is a minimum-threshold power level, each base station (312, 314, 316, 612, 614, 616) maintains its transmit power level at or above the minimum-threshold power level. When the threshold power level is a maximum-threshold power level, each base station (31 Z, 314, 316, 612, 614, 616) maintains its transmit power level at or below the maximum- threshold power level. Preferably, all power levels are expressed in decibels (dB) relative to the pilot's power level. The threshold power level can be adjustable or fixed. In the case whe re the threshold power level is fixed, each base station is programmed with the fixed thresho ld power level, and each base station decides how to adjust its transmit power level locally bas ed on the fixed threshold power level without input from other base stations. In the case where the threshold power level is adjustable, the threshold power level is adjusted by a threshold step size responsive to the transmit power level being substantially equal to the threshold power level for at least a predetermined percentage of a time period. There are two alternatives on how each base station decides how to adjust its transmit power level. In one alternative, each base station (312, 314, 316) participating in a soft handoff sends its power control information to a processor (328) which adjusts the threshold power level and notifies each ba se station of the new adjusted threshold power level. In the meantime, each base station uses its current threshold power level to locally adjust its transmit power level. In the oth er alternative, each base station (612, 614, 616) adjusts the threshold power level locally witho ut input from other base stations, and uses the threshold power level to adjust its transmit pow er level. Figure 5A.
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公开(公告)号：CA2317142C
公开(公告)日：2004-04-13
申请号：CA2317142
申请日：2000-08-30
Applicant: LUCENT TECHNOLOGIES INC
Inventor： WU XIAO CHENG , KUO WEN-YI , KAMEL RAAFAT EDWARD , MEYERS MARTIN HOWARD , WEAVER CARL FRANCIS
IPC: H04B1/04 , H04B7/005 , H04B7/26 , H04W52/12 , H04W52/14 , H04W52/40 , H04W52/50 , H04Q7/36 , H04Q7/38
Abstract: A method and system for controlling downlink transmit power during a soft hand-off in a spread-spectrum wireless system supports independent power control of multiple forward channels to reduce fading. For a soft hand-off, a mobile switching center determines if a forward control channel is transmitted from different sectors of base stations than a forward data channel is. The base stations preferably adjust transmit powers of the forward channels grouped into different physical channels by receiving power control data over the allocated reverse power control channels to compensate for fading of the forward channels during a soft hand-off.
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公开(公告)号：CA2317142A1
公开(公告)日：2001-03-02
申请号：CA2317142
申请日：2000-08-30
Applicant: LUCENT TECHNOLOGIES INC
Inventor： WEAVER CARL FRANCIS , WU XIAO CHENG , MEYERS MARTIN HOWARD , KAMEL RAAFAT EDWARD , KUO WEN-YI
IPC: H04B1/04 , H04B7/005 , H04B7/26 , H04W52/12 , H04W52/14 , H04W52/40 , H04W52/50 , H04Q7/36 , H04Q7/38
Abstract: A method and system for controlling downlink transmit power during a soft hand-off in a spread-spectrum wireless system supports independent power control of multiple forward channels to reduce fading. For a soft hand-off, a mobile switching center determines if a forward control channel is transmitted from different sectors of base stations than a forward data channel is. The base stations preferably adjust transmit powers of the forward channels grouped into different physical channels by receiving power control data over the allocated reverse power control channels to compensate for fading of the forward channels during a soft hand-off.
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