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公开(公告)号：BR0100361A
公开(公告)日：2001-10-02
申请号：BR0100361
申请日：2001-02-05
Applicant: LUCENT TECHNOLOGIES INC
Inventor： LAROIA RAJIV , RANGAN SUNDEEP , UPPALA SATHYADEV VENKATA , LI JUNYI
Abstract: An uplink synchronization and access control system is provided, in which mobile stations transmit certain timing and access signals in dedicated intervals in an uplink stream. Access control is illustratively implemented as a two-stage process, in which a given mobile first transmits a generic uplink access signal, in one of the intervals. If this access is accepted, the base station transmits an access acknowledgment, which contains initial timing and power corrections, along with initial channel assignments, on which the mobile can initiate a call set-up process. For re-synchronization, mobiles transmit timing synchronization signals in the dedicated timing and access intervals. The base station measures the arrival time of the signals, and sends back appropriate timing corrections. The invention thereby ensures that orthogonality between mobiles is maintained.
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公开(公告)号：BR0100359A
公开(公告)日：2001-10-02
申请号：BR0100359
申请日：2001-02-05
Applicant: LUCENT TECHNOLOGIES INC
Inventor： LAROIA RAJIV , RANGAN SUNDEEP , UPPALA SATHYADEV VENKATA , LI JUNYI
Abstract: Timing and access signals, to be transmitted in designated timing and access intervals, are constructed from orthogonal multitone signals. The multitone signals may be similar to multitone signals used in OFDM data transmission, except that a cyclic prefix, which is associated with reception of the signals in a base station, is extended to cover the timing errors of mobile stations not yet synchronized. Design techniques which optimize the time resolvability and peak-to-average ratio of the multitone signals, an efficient fast Fourier transform (FFT) based technique for maximum likelihood timing estimation, and a robust linear filtering technique for averaging timing estimates from different synchronizations, are also provided.
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公开(公告)号：BR0006806A
公开(公告)日：2001-07-24
申请号：BR0006806
申请日：2000-12-15
Applicant: LUCENT TECHNOLOGIES INC
Inventor： LAROIA RAJIV , LI JUNYI , RANGAN SUNDEEP , UPPALA SATHYADEV VENKATA
IPC: H04J11/00 , H04B1/7136 , H04B1/7143 , H04L5/02 , H04Q7/22
Abstract: Tone sequences in a frequency hopping arrangement are generated and assigned by advantageously employing a combination of a sequence generator and a sequence assignor to generate sequences and assign them on a time slot by time slot basis. In a transmitter, the sequence generator and sequence assignor, in combination with a user tone assignor are employed to generate and assign tone sequences to a user on a time slot by time slot basis. In a receiver, the sequence generator and sequence assignor, in combination with a user tone identifier are employed to generate sequences and to identify incoming tone sequences to a user on a time slot by time slot basis. Specifically, the sequence assignment in a time slot is such that a prescribed plurality of sequences is assigned to a particular user. This partitioning of the tasks facilitates the use of a sequence generator that generates sequences with the desirable properties of interference and frequency diversity and, which, leaves the task of properly assigning these sequences among one or more users to the sequence assignor. The sequence assignor functions in such a manner that the interference and frequency diversity properties for the one or more users are preserved, and this is further facilitated by assigning sequences in such a manner that they maximally overlap prior assigned sequences. In one example of the invention, a Latin square based sequence is generated in accordance with a first prescribed process. In an embodiment of the invention, a Latin cube based sequence is generated in accordance with a second prescribed process. In another embodiment of the invention, a Latin hypercube of prescribed dimension based sequence is generated in accordance with a third prescribed process. In still another embodiment of the invention, the principles of the invention are employed to realize frequency band hopping.
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公开(公告)号：BR0000988A
公开(公告)日：2000-10-17
申请号：BR0000988
申请日：2000-03-01
Applicant: LUCENT TECHNOLOGIES INC
Inventor： LAROIA RAJIV , LI JUNYI , VANDERVEEN MICHAELA C
Abstract: An orthogonal frequency division multiplexing (OFDM) based spread spectrum multiple access system using offsetting between cells, and in particular, the use of tone offsetting and time offsetting, is disclosed. More specifically, frequencies that define the tone set of one cell is offset from the frequencies that define the tone set of at least one adjacent cell. In other words, if a first base station is using tones F1, F2, ..., FN within a frequency band, then a second base station adjacent to the first base station uses tones F1+ DELTA f, F2+ DELTA f ..., FN+ DELTA f within the same frequency band. Furthermore, the symbol timing of the base-station of one cell may be offset from the symbol timing of the base-station of an adjacent cell. Thus, if a first base station starts successive symbols at times T1, T2, and T3, then a second base station adjacent to the first base station starts its respective corresponding successive symbols at times T1+ DELTA t, T2+ DELTA t, and T3+ DELTA t. For example, in a cellular system with hexagonally shaped cells, the tone sets of two adjacent cells are offset by 1/3 of the spacing between adjacent tones, and the symbol timings of two adjacent cells are offset by 1/3 of a symbol period. Advantageously, the intercell interference is more uniformly distributed among users in a cell.
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公开(公告)号：AU1956600A
公开(公告)日：2000-09-14
申请号：AU1956600
申请日：2000-03-01
Applicant: LUCENT TECHNOLOGIES INC
Inventor： LAROIA RAJIV , LI JUNYI , VANDERVEEN MICHAELA C
Abstract: An orthogonal frequency division multiplexing (OFDM) based spread spectrum multiple access system using offsetting between cells, and in particular, the use of tone offsetting and time offsetting, is disclosed. More specifically, frequencies that define the tone set of one cell is offset from the frequencies that define the tone set of at least one adjacent cell. In other words, if a first base station is using tones F1, F2, ..., FN within a frequency band, then a second base station adjacent to the first base station uses tones F1+ DELTA f, F2+ DELTA f ..., FN+ DELTA f within the same frequency band. Furthermore, the symbol timing of the base-station of one cell may be offset from the symbol timing of the base-station of an adjacent cell. Thus, if a first base station starts successive symbols at times T1, T2, and T3, then a second base station adjacent to the first base station starts its respective corresponding successive symbols at times T1+ DELTA t, T2+ DELTA t, and T3+ DELTA t. For example, in a cellular system with hexagonally shaped cells, the tone sets of two adjacent cells are offset by 1/3 of the spacing between adjacent tones, and the symbol timings of two adjacent cells are offset by 1/3 of a symbol period. Advantageously, the intercell interference is more uniformly distributed among users in a cell.
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Patent Agency Ranking
公开(公告)号：DE60130820D1
公开(公告)日：2007-11-22
申请号：DE60130820
申请日：2001-01-29
Applicant: LUCENT TECHNOLOGIES INC
Inventor： LAROIA RAJIV , LI JUNYI , RANGAN SUNDEEP , UPPALA SATHYADEV VENKATA
Abstract: An uplink synchronization and access control system is provided, in which mobile stations transmit certain timing and access signals in dedicated intervals in an uplink stream. Access control is illustratively implemented as a two-stage process, in which a given mobile first transmits a generic uplink access signal, in one of the intervals. If this access is accepted, the base station transmits an access acknowledgment, which contains initial timing and power corrections, along with initial channel assignments, on which the mobile can initiate a call set-up process. For re-synchronization, mobiles transmit timing synchronization signals in the dedicated timing and access intervals. The base station measures the arrival time of the signals, and sends back appropriate timing corrections. The invention thereby ensures that orthogonality between mobiles is maintained.
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27.发明专利
公开(公告)号：CA2331225C
公开(公告)日：2005-11-01
申请号：CA2331225
申请日：2001-01-12
Applicant: LUCENT TECHNOLOGIES INC
Inventor： UPPALA SATHYADEV VENKATA , LI JUNYI , LAROIA RAJIV , RANGAN SUNDEEP
Abstract: Improved timing synchronization and access control techniques for use in an orthogonal frequency division multiplexed (OFDM) wireless system or other ty pe of wireless communication system. In accordance with the invention, an uplink synchronization and access control system is provided in which mobile statio ns transmit certain timing and access signals in dedicated intervals in an uplink stream . Access control is illustratively implemented as a two-stage process in which a given mobile first transmits a generic uplink access signal in one of the intervals. If this access is accepted, the base station transmits an access acknowledgment containing initial timing and pow er corrections, along with initial channel assignments on which the mobile can initiate a ca ll set-up process. For re-synchronization, mobiles transmit timing synchronization signals in t he dedicated timing and access intervals. The base station measures the arrival time of t he signals, and sends back appropriate timing corrections. The invention thereby ensures tha t orthogonality between mobiles is maintained.
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公开(公告)号：CA2359514C
公开(公告)日：2005-07-12
申请号：CA2359514
申请日：2001-10-22
Applicant: LUCENT TECHNOLOGIES INC
Inventor： LI JUNYI , UPPALA SATHYADEV VENKATA , LAROIA RAJIV
Abstract: In a wireless communications system, multicast messages are transported to groups of wireless terminals by employing a common control channel to transm it a multicast paging message indicating that multicast traffic data is to be transmitted to a particular group of wireless terminals. In an embodiment of the invention, t he essential information transmitted in the common control channel is the identifier of t he group of wireless terminals intended to receive the multicast traffic data and the location of a traffic channel on which the multicast traffic is to be transported in a channel resource which may include a representation of bandwidth and time interval. In accordance with an aspect of the invention, the common control channel is associated with a traffic channel in a prescribed fixed manner. Further, the traffic channel used for the purpose of multicast can be the same traffic channel used for the normal point-to- point transmission of traffic data.
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公开(公告)号：CA2366343C
公开(公告)日：2005-06-28
申请号：CA2366343
申请日：2001-12-27
Applicant: LUCENT TECHNOLOGIES INC
Inventor： UPPALA SATHYADEV VENKATA , LAROIA RAJIV , LI JUNYI
Abstract: In a unique paging time slot format, each of the allocated paging time slo ts occurs periodically and is split into several prescribed paging time slots including at least one first type paging time slot having a relatively short duration and at least one second type paging time slot having a longer duration. The at leas t one first type paging time slots is of relatively short duration and transports an indication whether a particular associated wireless terminal was paged. The second type paging time slot is of longer duration than the first type time slot and transports the entire paging message. Specifically, a wireless terminal that is normally in a standby mode only has to enter a monitor mode, i.e., "wake up" , to monitor the relatively short first type paging time slot to determine whethe r it has been paged. If it has been paged, the wireless terminal then monitors the longer second type paging time slot to determine if it is transporting a valid pagi ng message for the paged wireless terminal. If no valid paged indication is detected in the first type paging time slot or no valid paging message is detected in the second type paging time slot, the wireless terminal returns to the standby mode, i.e., returns to a "sleep" state, and waits for the next periodic occurrence of its assigned paging time slot.
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公开(公告)号：DE60100534T2
公开(公告)日：2004-05-27
申请号：DE60100534
申请日：2001-08-20
Applicant: LUCENT TECHNOLOGIES INC
Inventor： LAROIA RAJIV , LI JUNYI , UPPALA SATHYADEV VENKATA
Abstract: Latency in receiving and detecting paging messages at a wireless terminal is reduced by employing a unique "super" paging time slot format. A paging super time slot includes a plurality of prescribed time slots. Each wireless terminal is associated with cyclically recurring super time slots. A super slot is associated with one or more wireless terminals. A base station always selects the first available time slot in a super time slot to transmit a paging message to a wireless terminal that is associated with the super time slot. Each wireless terminal monitors every time slot in the associated super time slot until either detecting reception of its associated paging message or detecting an empty time slot. In another embodiment of the invention, a unique partially overlapping super time slot format is employed in which a super time slot has at least one time slot common to its adjacent super time slots. This allows wireless terminals associated with adjacent super time slots to share the common at least one time slot. In turn, this results in balanced traffic loads, smoothed traffic fluctuation and reduced congestion.
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