公开(公告)号：DE60000096T2

公开(公告)日：2002-10-31

申请号：DE60000096

申请日：2000-02-28

Applicant: LUCENT TECHNOLOGIES INC

Inventor： LAROIA RAJIV ,  LI JUNYI ,  VANDERVEEN MICHAELA CATALINA

IPC: H04J11/00 ,  H04L5/02 ,  H04Q7/38

Abstract: In an orthogonal frequency division multiplexing (OFDM) based spread spectrum multiple access system the entire bandwidth is divided into orthogonal tones, and all of the orthogonal tones are reused in each cell. To reduce peak-to-average ratio at the mobile transmitter, each voice user is allocated preferably a single one, but no more than a very small number, of the orthogonal tones for use in communicating with the base station. Data users are similarly allocated tones for data communication, however, the number of tones assigned for each particular data user is a function of the data rate for that user. The tone assignment for a given user is not always the same within the available band, but instead the tones assigned to each user are hopped over time. More specifically, in the downlink, the tones assigned to each user are change relatively rapidly, e.g., from symbol to symbol, i.e., the user fast "hops" from one tone to another. However, in the uplink, preferably slow hopping is employed to allow efficient modulation of the uplink signal which necessitates the employing of additional techniques, such as interleaving, to compensate for the reduction in the intercell interference averaging effect. For data communication power control is employed in the uplink and/or downlink so that the transmission rate is increased, e.g., by increasing the number of symbols transmitted per tone per unit time or the coding rate, as a function of allocated power per tone and the corresponding channel attenuation.

公开(公告)号：DE60000193D1

公开(公告)日：2002-07-11

申请号：DE60000193

申请日：2000-02-28

Applicant: LUCENT TECHNOLOGIES INC

Inventor： LAROIA RAJIV ,  LI JUNYI ,  VANDERVEEN MICHAELA CATALINA

IPC: H04J11/00 ,  H04J13/00 ,  H04L5/02 ,  H04Q7/36

Abstract: A base station within a cell of an orthogonal frequency division multiplexing (OFDM) based spread spectrum multiple access system employs sectorization as a way to reduce the intercell interference. The cell is sectorized from a transmission point of view by the directionality of the downlink antenna, and the OFDM tone set employed in each cell is correspondingly sectorized, i.e., each sector in the cell is allocated a set of tones within a sub-band of the available frequency bandwidth for use when transmitting into that sector. The sub-bands assigned to each sector are periodically changed, or "hopped", among the available sub-bands within the totally available bandwidth. Such sub-band hopping is a so-called "slow" hopping, in that it is not performed on a symbol-by-symbol basis but instead occurs only after more than one symbol has been transmitted in a sector on tones within the sub-band. Each sector employs its own pilot signal, which is assigned one or more tones within the sub-band currently employed by that sector. Similarly, for the uplink, the base station may employ a directional receiver antenna. Preferably, the mobile terminal only transmits on a tone that is within a sub-band that is allocated to the sector in which the mobile terminal is located. This, sub-band, however, need not correspond to the same location within the bandwidth as the sub-band used by the downlink to communicate with the mobile terminal.

公开(公告)号：CA2366253A1

公开(公告)日：2002-07-08

申请号：CA2366253

申请日：2001-12-27

Applicant: LUCENT TECHNOLOGIES INC

Inventor： UPPALA SATHYADEV VENKATA ,  LAROIA RAJIV ,  LI JUNYI

IPC: H04J3/00 ,  H04W68/00 ,  H04Q7/34 ,  H04Q7/36

Abstract: An unique arrangement including a so-called timing control order and timing control signals is employed to identify whether wireless terminals ar e reachable within a base station cell coverage area in a wireless communications system. To this end, detection of a particular wireless terminal being alive and well, and within the cell coverage area associated with a base station is effected by the base station transmitting a timing control order in a timing control time slot reserved for the particular wireless terminal. If the particular wireless terminal receives the timing control order, it transmits a prescribed timing control message at a prescribed time. If the base station does not receive the timing contro l message, it is an indication that communication with the particular wireless terminal has been lost.

公开(公告)号：BR0104819A

公开(公告)日：2002-07-02

申请号：BR0104819

申请日：2001-10-25

Applicant: LUCENT TECHNOLOGIES INC

Inventor： LAROIA RAJIV ,  UPPALA SATHYADEV VENKATA ,  LI JUNYI

IPC: H04B7/26 ,  H04L12/18 ,  H04L12/28 ,  H04W68/00 ,  H04W74/00 ,  H04Q7/38

Abstract: In a wireless communications system, multicast messages are transported to groups of wireless terminals by employing a common control channel to transmit 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, the essential information transmitted in the common control channel is the identifier of the 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：CA2351971A1

公开(公告)日：2002-02-16

申请号：CA2351971

申请日：2001-06-29

Applicant: LUCENT TECHNOLOGIES INC

Inventor： LI JUNYI ,  UPPALA SATHYADEV VENKATA ,  LAROIA RAJIV

IPC: H04J11/00 ,  H04L5/02 ,  H04W36/00 ,  H04Q7/36 ,  H04Q7/38

Abstract: Uplink traffic channel allocation is realized by utilizing a dedicated contr ol channel in which a prescribed portion of the control channel resource, for example, frequency, time slot or the like, is reserved for transporting the uplink traffic channel requests. Both the base station and the particular mobile unit know the prescribed portion of the control channel resource a priori. Consequently, when the particular mobile unit transmits an uplink traffic channel request via the prescribed portion of the control channel resource there is no need for adding any control header information, thereby minimizing overhead. Furthermore, the length of the uplink traffic channel requests can be optimally chosen without constraints imposed by other contro l message schemes. Reduced overhead coupled with the prescribed portion of the control channel resource arriving quite frequently reduces latency in the particular mobile unit acquiring an uplink traffic channel. In one example, delivery of adequate uplink traffic channel request information to the base station, while minimizing the adverse impact of losing requests, is ensured by persistently transmitting t he requests. Specifically, after the mobile unit transmits a first request, it transmits a second or even a third request instead of waiting to receive a response message from t he base station and/or waiting for a timer to time out. By the mobile unit using suc h a persistent request transmission scheme, the base station can readily determi ne the true value of the received request by eliminating the transmission loop delay effect, thereby allowing a sensible assignment decision to be made.

公开(公告)号：CA2344839A1

公开(公告)日：2001-12-19

申请号：CA2344839

申请日：2001-04-23

Applicant: LUCENT TECHNOLOGIES INC

Inventor： LAROIA RAJIV ,  UPPALA SATHYADEV VENKATA ,  LI JUNYI

IPC: H04L12/28 ,  H04W72/04 ,  H04W72/14 ,  H04Q7/36

Abstract: Access request transmissions are effected in a wireless communications syst em 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 ba se 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 reques t response message.

公开(公告)号：AU3517501A

公开(公告)日：2001-10-25

申请号：AU3517501

申请日：2001-04-12

Applicant: LUCENT TECHNOLOGIES INC

Inventor： LAROIA RAJIV ,  VISWANATH PRAMOD ,  RANGAN SUNDEEP ,  LI JUNYI

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

Abstract: A base station having the strongest downlink signal is identified by utilizing a unique slope of a pilot tone hopping sequence being transmitted by a base station. Specifically, base station identification is realized by determining the slope of the strongest received pilot signal, i.e., the received pilot signal having the maximum energy. In an embodiment of the invention, the pilot tone hopping sequence is based on a Latin Squares sequence. With a Latin Squares based pilot tone hopping sequence, all a mobile user unit needs is to locate the frequency of the pilot tones at one time because the pilot tone locations at subsequent times can be determined from the slope of the Latin Squares pilot tone hopping sequence. The slope and initial frequency shift of the pilot tone hopping sequence with the strongest received power is determined by employing a unique maximum energy detector. In one embodiment, the slope and initial frequency shift of the pilot signal having the strongest received power is determined by finding the slope and initial frequency shift of a predicted set of pilot tone locations having the maximum received energy. In another embodiment, the frequency shift of the pilot signal with the strongest, i.e., maximum, received power is estimated at each of times "t". These frequency shifts are employed in accordance with a prescribed relationship to determine the unknown slope and the initial frequency shift of the pilot signal.

公开(公告)号：BR0000966A

公开(公告)日：2000-12-05

申请号：BR0000966

申请日：2000-02-28

Applicant: LUCENT TECHNOLOGIES INC

Inventor： LAROIA RAJIV ,  LI JNYI ,  VANDERVEEN MICHAELA C

IPC: H04J11/00 ,  H04J13/00 ,  H04L5/02 ,  H04Q7/36 ,  H04B1/713 ,  H04Q7/30

Abstract: A base station within a cell of an orthogonal frequency division multiplexing (OFDM) based spread spectrum multiple access system employs sectorization as a way to reduce the intercell interference. The cell is sectorized from a transmission point of view by the directionality of the downlink antenna, and the OFDM tone set employed in each cell is correspondingly sectorized, i.e., each sector in the cell is allocated a set of tones within a sub-band of the available frequency bandwidth for use when transmitting into that sector. The sub-bands assigned to each sector are periodically changed, or "hopped", among the available sub-bands within the totally available bandwidth. Such sub-band hopping is a so-called "slow" hopping, in that it is not performed on a symbol-by-symbol basis but instead occurs only after more than one symbol has been transmitted in a sector on tones within the sub-band. Each sector employs its own pilot signal, which is assigned one or more tones within the sub-band currently employed by that sector. Similarly, for the uplink, the base station may employ a directional receiver antenna. Preferably, the mobile terminal only transmits on a tone that is within a sub-band that is allocated to the sector in which the mobile terminal is located. This, sub-band, however, need not correspond to the same location within the bandwidth as the sub-band used by the downlink to communicate with the mobile terminal.

公开(公告)号：BR0000965A

公开(公告)日：2000-12-05

申请号：BR0000965

申请日：2000-02-28

Applicant: LUCENT TECHNOLOGIES INC

Inventor： LAROIA RAJIV ,  LI JUNYI ,  VANDERVEEN MICHAELA C

IPC: H04J11/00

公开(公告)号：AU2063600A

公开(公告)日：2000-09-14

申请号：AU2063600

申请日：2000-03-03

Applicant: LUCENT TECHNOLOGIES INC

Inventor： LAROIA RAJIV ,  LI JUNYI ,  VANDERVEEN MICHAELA C

IPC: H04J11/00 ,  H04J13/00 ,  H04L5/02 ,  H04Q7/36 ,  H04B7/216 ,  H04B7/26 ,  H04J13/02

Abstract: A base station within a cell of an orthogonal frequency division multiplexing (OFDM) based spread spectrum multiple access system employs sectorization as a way to reduce the intercell interference. The cell is sectorized from a transmission point of view by the directionality of the downlink antenna, and the OFDM tone set employed in each cell is correspondingly sectorized, i.e., each sector in the cell is allocated a set of tones within a sub-band of the available frequency bandwidth for use when transmitting into that sector. The sub-bands assigned to each sector are periodically changed, or "hopped", among the available sub-bands within the totally available bandwidth. Such sub-band hopping is a so-called "slow" hopping, in that it is not performed on a symbol-by-symbol basis but instead occurs only after more than one symbol has been transmitted in a sector on tones within the sub-band. Each sector employs its own pilot signal, which is assigned one or more tones within the sub-band currently employed by that sector. Similarly, for the uplink, the base station may employ a directional receiver antenna. Preferably, the mobile terminal only transmits on a tone that is within a sub-band that is allocated to the sector in which the mobile terminal is located. This, sub-band, however, need not correspond to the same location within the bandwidth as the sub-band used by the downlink to communicate with the mobile terminal.