公开(公告)号：AU3517701A

公开(公告)日：2001-10-25

申请号：AU3517701

申请日：2001-04-12

Applicant: LUCENT TECHNOLOGIES INC

Inventor： LAROIA RAJIV ,  UPPALA SATHYADEV VENKATA ,  LI JUNYI

IPC: H04J11/00 ,  H04B1/7143 ,  H04B1/7156 ,  H04B1/76 ,  H04B7/26 ,  H04L5/02 ,  H04L27/26 ,  H04Q7/20 ,  H04B1/713 ,  H04B7/216 ,  H04J13/06 ,  H04Q7/30

Abstract: Base station identification and downlink synchronization are realized by employing pilots including known symbols transmitted at prescribed frequency tones in individual ones of prescribed time intervals. Specifically, the symbols used in the pilots are uniquely located in a time- frequency grid, where the locations are specified by periodic pilot tone hopping sequences. In a specific embodiment of the invention, a period of a pilot tone hopping sequence is constructed by starting with a Latin-square based hopping sequence, truncating it over time, and possibly offsetting and permuting it over frequency. Particular examples of pilot tone hopping sequences are parallel slope hopping sequences in which the periodicity of the sequences is chosen to be a prime number of symbol time intervals. In another embodiment of the invention, a notion of phantom pilots is employed to facilitate use of various system parameters while accommodating the above noted pilot tone hopping sequences. That is, based on system considerations the frequency range of the above generated pilot tone hopping sequences exceeds the available bandwidth of a particular system, which would be a problem. This problem is overcome by truncating the pilot tone hopping sequences whenever the tone frequency exceeds the bandwidth, that is, designating these tones as phantom pilot tones and not transmitting them.

公开(公告)号：CA2339515A1

公开(公告)日：2001-10-18

申请号：CA2339515

申请日：2001-03-05

Applicant: LUCENT TECHNOLOGIES INC

Inventor： UPPALA SATHYADEV VENKATA ,  LI JUNYI ,  LAROIA RAJIV

IPC: H04J11/00 ,  H04B1/7143 ,  H04B1/7156 ,  H04B1/76 ,  H04B7/26 ,  H04L5/02 ,  H04L27/26 ,  H04B1/713 ,  H04B7/208

Abstract: Base station identification and downlink synchronization are realized b y employing pilots including known symbols transmitted at prescribed frequency tones in individual ones of prescribed time intervals. Specifically, the symbols used in the pilots are uniquely located in a time- frequency grid, where the locations are specified by periodic pilot tone hopping sequences. In a specific embodiment of the invention, a period of a pilot tone hopping sequence is constructed by starting with a Latin-square based hopping sequence, truncating it over time, and possibly offsetting and permuting it over frequency. Particular examples of pilot tone hopping sequences are parallel slope hopping sequences in which the periodicity of the sequences is chosen to be a prime number of symbol time intervals. In another embodiment of the invention, a notion of phantom pilots is employed to facilitate use of various system parameters while accommodating the above noted pilot tone hopping sequences. That is, based o n system considerations the frequency range of the above generated pilot tone hopping sequences exceeds the available bandwidth of a particular system, which would be a problem. This problem is overcome by truncating the pilot tone hopping sequences whenever the tone frequency exceeds the bandwidth,that is, designating these tones as phantom pilot tones and not transmitting them.

公开(公告)号：CA2331225A1

公开(公告)日：2001-08-11

申请号：CA2331225

申请日：2001-01-12

Applicant: LUCENT TECHNOLOGIES INC

Inventor： LAROIA RAJIV ,  LI JUNYI ,  RANGAN SUNDEEP ,  UPPALA SATHYADEV VENKATA

IPC: H04J11/00 ,  H04B7/26 ,  H04L5/02 ,  H04L7/00 ,  H04L27/26 ,  H04Q7/36

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.

公开(公告)号：CA2327980A1

公开(公告)日：2001-06-23

申请号：CA2327980

申请日：2000-12-08

Applicant: LUCENT TECHNOLOGIES INC

Inventor： LAROIA RAJIV ,  LI JUNYI ,  UPPALA SATHYADEV VENKATA ,  RANGAN SUNDEEP

IPC: H04J11/00 ,  H04B1/7136 ,  H04B1/7143 ,  H04L5/02

Abstract: Tone sequences in a frequency hopping arrangement are generated and assign ed 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 wi th a user tone assignor are employed to generate and assign tone sequences to a user o n 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 a nd 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 prescrib ed 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 sequen ce 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 embodiment of the invention, a Latin square based sequence is generated in accordance with a first prescribed process. In a second embodiment of the invention, a Latin cube based sequence is generated in accordance with a second prescribed process. In a third embodiment of the invention, a Latin hypercub e 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.

公开(公告)号：DE69703233D1

公开(公告)日：2000-11-09

申请号：DE69703233

申请日：1997-12-02

Applicant: LUCENT TECHNOLOGIES INC

Inventor： LAROIA RAJIV ,  YEO BOON-LOCK

IPC: G10L19/04 ,  G10L19/02 ,  G10L19/06 ,  H03M7/30 ,  H04B14/04 ,  G10L101/20

Abstract: Coding systems that provide a perceptually improved approximation of the short-term characteristics of speech signals compared to typical coding techniques such as linear predictive analysis while maintaining enhanced coding efficiency. The invention advantageously employs a non-linear transformation and/or a spectral warping process to enhance particular short-term spectral characteristic information for respective voiced intervals of a speech signal. The non-linear transformed and/or warped spectral characteristic information is then coded, such as by linear predictive analysis to produce a corresponding coded speech signal. The use of the non-linear transformation and/or spectral warping operation of the particular spectral information advantageously causes more coding resources to be used for those spectral components that contribute greater to the perceptible quality of the corresponding synthesized speech. It is possible to employ this coding technique in a variety of speech coding techniques including, for example, vocoder and analysis-by-synthesis coding systems.

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

IPC: H04J11/00 ,  H04L27/26 ,  H04B7/26 ,  H04L5/02 ,  H04L7/00

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.

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

IPC: H04J11/00 ,  H04B7/26 ,  H04L5/02 ,  H04L7/00 ,  H04L27/26 ,  H04Q7/36

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.

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

IPC: H04B7/26 ,  H04L12/18 ,  H04L12/28 ,  H04W68/00 ,  H04W74/00 ,  H04Q7/36 ,  H04B7/204

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.

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

IPC: H04J11/00 ,  H04J3/00 ,  H04W52/02 ,  H04W68/02 ,  H04Q7/38

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.

公开(公告)号：DE60101022T2

公开(公告)日：2004-07-08

申请号：DE60101022

申请日：2001-06-11

Applicant: LUCENT TECHNOLOGIES INC

Inventor： LAROIA RAJIV ,  JUNYL LI ,  UPPALA SANTHYADEV VENKATA

IPC: H04L12/28 ,  H04W72/04 ,  H04W72/14 ,  H04Q7/38 ,  H04L12/56

Abstract: Access request transmissions are effected in a wireless communications system by assigning each mobile unit a unique dedicated uplink resource. Specifically, each mobile unit is assigned channel segments with distinct time slot indices and/or waveform indices, where waveforms with distinct indices are orthogonal. A base station can identify the mobile that has made an access request from the dedicated uplink resource. Therefore, no mobile identification number is needed in the uplink request message. Then, the base station can transmit a request response message on a shared downlink resource that may include the identification number of the requesting mobile unit to acknowledge reception of the request. The mobile unit may transmit on a shared uplink resource an acknowledgment of reception of the downlink request response message.