Xiao Dong Wu

US Patent:

6496531, Dec 17, 2002

Filed:

Sep 2, 1999

Appl. No.:

09/389080

Inventors:

Raafat Edward Kamel - Westfield NJ
Wen-Yi Kuo - Morganville NJ
Martin Howard Meyers - Montclair NJ
Carl Francis Weaver - Hanover Township NJ
Xiao Cheng Wu - Parsippany NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H04B 1713

US Classification:

375130, 455442, 455450

Abstract:

A method and system for controlling down link 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.

US Patent:

6504827, Jan 7, 2003

Filed:

Dec 18, 1998

Appl. No.:

09/215437

Inventors:

Wen-Yi Kuo - Parsippany NJ
Martin Howard Meyers - Montclair NJ
Xiao Cheng Wu - Parsippany NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H04Q 700

US Classification:

370329, 370345, 370468

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.

US Patent:

6590873, Jul 8, 2003

Filed:

Feb 5, 1999

Appl. No.:

09/245204

Inventors:

Quinn Li - Madison NJ
Martin Howard Meyers - Montclair NJ
John Minkoff - Englewood NJ
Xiao Cheng Wu - Parsippany NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H04B 7185

US Classification:

370318, 370491, 370500

Abstract:

The invention is a method for controlling power on multiple forward link communication channels by using multiple power control sub-channels, wherein each power control sub-channel is associated with a forward link communication channel to be power controlled. A fundamental power control sub-channel and a supplemental power control sub-channel are time multiplexed onto a reverse pilot channel. Transmitted over the fundamental power control sub-channel is a fundamental power control bit for indicating to a base station to increase or decrease its transmission power over a corresponding forward fundamental channel. Transmitted over the supplemental power control sub-channel is a supplemental power control bit for indicating to a base station to increase or decrease its transmission power over a corresponding forward supplemental channel. The pilot sub-channels are preferably separated by the fundamental and supplemental power control sub-channels for time diversity purposes.

US Patent:

6594243, Jul 15, 2003

Filed:

Jul 15, 1999

Appl. No.:

09/354220

Inventors:

Ching Yao Huang - Randolph NJ
Joe Huang - Parsippany NJ
I-Fong Antonio Wu - Randolph NJ
Xiao Cheng Wu - Parsippany NJ
Bee Yun Yu - Morristown NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H04Q 700

US Classification:

370332, 455442

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.

US Patent:

6628957, Sep 30, 2003

Filed:

Jul 16, 1999

Appl. No.:

09/354696

Inventors:

Carl Francis Weaver - Hanover Township, Morris County NJ
Xiao Cheng Wu - Parsippany NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H04B 700

US Classification:

455522, 455442, 370331

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 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 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 pilots power level. The threshold power level can be adjustable or fixed. In the case where the threshold power level is fixed, each base station is programmed with the fixed threshold power level, and each base station decides how to adjust its transmit power level locally based 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.

US Patent:

6628958, Sep 30, 2003

Filed:

Sep 15, 1999

Appl. No.:

09/396947

Inventors:

Raafat Edward Kamel - Westfield NJ
Martin Howard Meyers - Montclair NJ
Carl Francis Weaver - Hanover Township, Morris County NJ
Xiao Cheng Wu - Parsippany NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H04Q 720

US Classification:

455522, 455437, 4552451, 370331

Abstract:

A base station in a soft handoff adjusts its transmit power level by a first amount if the base station is participating in a soft handoff and by a second amount if the base station is not participating in the soft handoff, i. e. in simplex mode. The first and second amounts are different. In one embodiment of the invention, the adjustment is performed by using a down-step size that is larger in magnitude than an up-step size when the base station is in soft handoff. The transmit power level is then adjusted by the smaller up and larger down step sizes when the base station receives an indication to adjust the transmit power level. The step sizes used when the base station is in simplex mode is larger than the up-step size and smaller than the down step size. In another embodiment, when the base station is in soft handoff, the adjustment is performed by adjusting the transmit power level by the same step size as used during simplex mode when the base station receives an indication to adjust the transmit power level and then reducing the result by a reduction amount. The order of these two steps can be reversed, and the transmit power level can be first reduced by the reduction amount and then adjusted by the same step sizes as used during simplex mode.

US Patent:

6671127, Dec 30, 2003

Filed:

Jul 25, 2001

Appl. No.:

09/916094

Inventors:

Yimin Hsu - Sunnyvale CA
Andreas Moser - San Jose CA
Hemantha K. Wickramasinghe - San Jose CA
Xiao Z. Wu - San Jose CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G11B 5147

US Classification:

360123

Abstract:

A thermally-assisted magnetic recording (TAMR) write head simultaneously generates heat and a magnetic write field to the recording layer on a magnetic recording disk. The write head is located on the trailing face of a head carrier in a TAMR disk drive and comprises a single turn coil, part of which is a current strip having an edge located at the disk-facing surface of the head carrier. When write current is passed through the current strip heat is generated at the edge of the strip and a magnetic write field is induced at the disk surface. The strip edge has a predetermined width that substantially corresponds to the desired track width of the data bits. Because both heat and the magnetic write field are generated by the same element, the heat gradient and the magnetic write field gradient are co-located on the spot where the data bit is written.

US Patent:

6697343, Feb 24, 2004

Filed:

Aug 26, 1999

Appl. No.:

09/383233

Inventors:

Raafat Edward Kamel - Westfield NJ
Wen-Yi Kuo - Parsippany NJ
Martin Howard Meyers - Montclair NJ
Carl Francis Weaver - Hanover Township NJ
Xiao Cheng Wu - Parsippany NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

G08C 1700

US Classification:

370311, 370278, 370332, 370470, 455 69, 455522, 455574, 704221, 714701, 714704

Abstract:

A base station assembles a frame including information bits at a vocoding rate for downlink transmission over a traffic channel as channel bits at a channel rate. The base station places at least one rate-indicating bit at a beginning of the frame for indicating the vocoding rate. The mobile station evaluates the downlink transmission with consideration of the vocoding rate indicated by the at least one rate-indicating bit. The mobile station can determine the vocoding rate by decoding the beginning of the frame to permit power control in less than one frame duration from initial receipt of the frame at the mobile station.