公开(公告)号：AU5191201A

公开(公告)日：2001-12-20

申请号：AU5191201

申请日：2001-06-14

Applicant: LUCENT TECHNOLOGIES INC

Inventor： LAROIA RAJIV ,  LI JUNYI ,  UPPALA SATHYADEV VENKATA

IPC: H04W24/00 ,  H04W28/04 ,  H04W68/00 ,  H04W72/04 ,  H04W74/00 ,  H04Q7/22 ,  H04Q7/30 ,  H04Q7/32 ,  H04Q7/26

Abstract: In a wireless communication system, mobile unit and base station access request and page transmissions are addressed by employing an efficient unified approach for the transmission and detection of both access requests from a mobile unit and pages from a base station. To this end, a mobile unit monitors for access requests and monitors a prescribed resource to detect if a page has been received. Upon detection of an access request, a corresponding request message is generated and transmitting substantially immediately to a base station, thereby minimizing latency in the access process. Concurrently, a base station monitors to determine if a page indication has been received and monitors a prescribed resource to determine if an access request message has been received. In this process, the processing of request messages takes precedence over the processing of pages. Upon detecting a received request message a request response message is generated and transmitted substantially immediately to the mobile unit, thereby also minimizing latency in the access process.

公开(公告)号：CA2330776A1

公开(公告)日：2001-08-11

申请号：CA2330776

申请日：2001-01-12

Applicant: LUCENT TECHNOLOGIES INC

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

IPC: H04J11/00 ,  H04B7/26 ,  H04J3/06 ,  H04L5/02 ,  H04L7/10 ,  H04L27/26 ,  H04Q7/36

Abstract: Signal construction, detection and estimation techniques for use in uplink timing synchronization and access control in an orthogonal frequency division multiplexed (OFDM) wireless system or other type of wireless communication system. In accordanc e with an illustrative embodiment of the invention, 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 associated with reception of the signals in a ba se station is extended to cover the timing errors of mobile stations not yet synchronized. The invention also provides design techniques which optimize the time resolvability and pe ak- 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 techniqu e for averaging timing estimates from different synchronizations.

公开(公告)号：AU7229800A

公开(公告)日：2001-06-28

申请号：AU7229800

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 ,  H04J13/02

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.