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公开(公告)号：DE60037161D1
公开(公告)日：2008-01-03
申请号：DE60037161
申请日：2000-05-09
Applicant: LUCENT TECHNOLOGIES INC
Inventor： KRISHNAMOORTHY RAJEEV , RUPP MARKUS , VISWANATHAN HARISH
Abstract: In a TDMA system a multifunction control channel is employed that carries data used for implementing channel access functionality for users and is also employed at the remote terminals in the performance of modem functionality. In other words, information necessary to accurately receive data on the user traffic channels is obtainable by processing the multifunction control channel. This is achieved by arranging the broadband channel of the TDMA system as a repeating frame having time slots in which at least one time slot is reserved for use as the multifunction control channel, and the data that is transmitted on the multifunction control channel is encoded using a spread spectrum format. To this end the data carried on the multifunction control channel is encoded in a way that uses each symbol of the multifunction control channel as if it were a so-called spread spectrum "chip". At least one of the remaining time slots of the frame, and preferably all of the remaining time slots, which are typically used to carry user traffic arranged as logical channels, are not spread spectrum encoded. With regard to modem functionality, the remote terminals use the received multifunction control channel to a) perform frame synchronization, i.e., frame timing, b) perform frequency offset estimation, c) obtain an estimate of the channel impulse response, and d) estimate the received signal strength for use in gain control.
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公开(公告)号：CA2313818C
公开(公告)日：2007-07-10
申请号：CA2313818
申请日：2000-07-12
Applicant: LUCENT TECHNOLOGIES INC
Inventor： VISWANATHAN HARISH , RUPP MARKUS , NARAYANASWAMY SHANKAR , KRISHNAMOORTHY RAJEEV , LI XIAODONG
Abstract: In a wireless communication system, the constellation mapping scheme employe d may be changed on a per-time-slot basis, i.e., from time slot to time slot, so that the constellation used to encode the symbols of each time slot may be different for each time slot within a single frame and may be different for a particular time slot i n different consecutive frames. In other words, several constellation mapping schemes ar e available, with each providing the ability to transmit a different number of bits per symbol, and the particular constellation mapping scheme employed for any time slot need be selected for that time slot only. The ability to use any particular constellation mapping scheme is dependent on the current channel quality. The particular constellation mappi ng used for the user data of the time slot may be indicated in the preamble of the time slot. To this end, each time slot may have its own preamble that is mapped with a constellation mapping scheme which is a) known à priori, b) may be the same for all time slots, and c) may be different from the constellation mapping scheme used to encode user data in the time slot. A receiver can determine the constellation mapping used for each time slot from solely from the preamble of the time slot.
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公开(公告)号：CA2352010C
公开(公告)日：2005-05-24
申请号：CA2352010
申请日：2001-07-03
Applicant: LUCENT TECHNOLOGIES INC
Inventor： RUPP MARKUS
IPC: H04L27/18 , H04B1/10 , H04B3/06 , H04B7/04 , H04B7/06 , H04B7/08 , H04J11/00 , H04J13/10 , H04L7/00 , H04B1/18 , H04B7/204
Abstract: Orthogonal sequences can be developed and used for use training and synchronizing in CDMA and TDMA systems. In particular, once a sequence is developed that has the length of the product of the channel length and the number of transmit antennas, the sequence is offset by a different amount for each transmit antenna. For example, each sequence could be offset by a multiple of the channel leng th for each transmit antenna, where the multiple ranges from 0 to N-1, where N is the number of transmit antennas. Furthermore, by not using exactly the same amount of offs et shifting for each transmit antenna, e.g., not having each signal offset by the channe l length, but keeping the overall total shifting the same, e.g., the average of each shift is the channel length, it is possible to determine at a receiver from which transmit antenn a a particular signal originated.
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公开(公告)号：CA2307490C
公开(公告)日：2004-08-10
申请号：CA2307490
申请日：2000-05-04
Applicant: LUCENT TECHNOLOGIES INC
Inventor： RUPP MARKUS , KRISHNAMOORTHY RAJEEV , VISWANATHAN HARISH
IPC: H04B1/7075 , H04B7/26 , H04J3/00 , H04W28/26 , H04W74/02 , H04W74/04 , H04W99/00 , H04B7/212 , H04Q7/36 , H04B1/69
Abstract: In a TDMA system a multifunction control channel is employed that carries data used for implementing channel access functionality for users and is also employed at the remote terminals in the performance of modem functionality. In other words, information necessary to accurately receive data on the user traffic channels is obtainable by processing the multifunction control channel. This is achieved by arranging the broadband channel of the TDMA system as a repeating frame having time slots in which at least one time slot is reserved for use as the multifunction control channel, and the data that is transmitted on the multifunction control channel is encoded using a spread spectrum format. To this end the data carried on the multifunction control channel is encoded in a way that uses each symbol of the multifunction control channel as if it were a so-called spread spectrum "chip". At least one of the remaining time slots of the frame, and preferably all of the remaining time slots, which are typically used to carry user traffic arranged as logical channels, are not spread spectrum encoded. With regard to modem functionality, the remote terminals use the received multifunction control channel to a) perform frame synchronization, i.e., frame timing, b) perform frequency offset estimation, c) obtain an estimate of the channel impulse response, and d) estimate the received signal strength for use in gain control.
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公开(公告)号：AU6355901A
公开(公告)日：2002-03-07
申请号：AU6355901
申请日：2001-08-21
Applicant: LUCENT TECHNOLOGIES INC
Inventor： RUPP MARKUS
IPC: H04L27/01 , H04B1/10 , H04B1/69 , H04B3/10 , H04J13/00 , H04J13/10 , H04J13/12 , H04L25/03 , H04B1/06 , H04L1/02
Abstract: Use of a training sequence having terms that are orthogonal to each other are employed to considerably speed up execution of the LMS algorithm. Such orthogonal sequences are developed for a channel that is described as a finite impulse response (FIR) filter having a length Mnew from the already existing orthogonal training sequences for at least two channels that have respective lengths Mold1 and Mold2 each that is less than Mnew such that the product of Mold1 and Mold2 is equal to Mnew when Mold1 and Mold2 have no common prime number factor. More specifically, a set of initial existing orthogonal training sequences is found, e.g., using those that were known in the prior art or by performing a computer search over known symbol constellations given a channel of length M. Thereafter, an orthogonal training sequence of length Mnew is developed, where the product of Mold1 and Mold2 is equal to Mnew by repeating the training sequence old1 Mold2 number of times to form a first concatenated sequence and repeating the training sequence old2 Mold1 number of times to form a second concatenated sequence, so that both the first concatenated sequence and the second concatenated sequence have the same length. Each term of the first concatenated sequence is multiplied by the correspondingly located term in the second concatenated sequence which is placed in the same location in a new sequence made up of the resulting Mnew products. This new sequence is an orthogonal sequence of length Mnew.
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Patent Agency Ranking
公开(公告)号：BR0002977A
公开(公告)日：2001-03-13
申请号：BR0002977
申请日：2000-07-19
Applicant: LUCENT TECHNOLOGIES INC
Inventor： KRISHNAMOORTHY RAJEEV , VISWANATHAN HARISH , NARAYANASWAMY SHANKAR , RUPP MARKUS
Abstract: In a system in which the modulation scheme employed may change on a per-time-slot basis, a user's available data rate may change even if the user maintains the same number of time slots, because the capacity of the user's time slots may change. If one or more such changes in modulation scheme occurs, the data rate available to the user may no longer match his current data rate needs. Therefore, a method is disclosed for determining the number of time slots to assign to a user as a function of the user's current data rate requirement and the actual current cumulative data rate of the time slots currently assigned to the user. The user data rate requirement may further be a function of a quality of service (QoS) contracted for by the user. Thus, the assignment of the time slots within the frame is made dynamically and the number of time slots employed by a user is increased or decreased according to the user's current data rate requirements and the ability of the time slots already assigned to the user to meet those requirements.
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公开(公告)号：AU4869700A
公开(公告)日：2001-02-08
申请号：AU4869700
申请日：2000-07-19
Applicant: LUCENT TECHNOLOGIES INC
Inventor： KRISHNAMOORTHY RAJEEV , NARAYANASWAMY SHANKAR , RUPP MARKUS , VISWANATHAN HARISH
IPC: H04B7/24 , H04L1/00 , H04L12/56 , H04W24/00 , H04W28/22 , H04W72/04 , H04W74/04 , H04B7/204 , H04L12/00
Abstract: In a system in which the modulation scheme employed may change on a per-time-slot basis, a user's available data rate may change even if the user maintains the same number of time slots, because the capacity of the user's time slots may change. If one or more such changes in modulation scheme occurs, the data rate available to the user may no longer match his current data rate needs. Therefore, a method is disclosed for determining the number of time slots to assign to a user as a function of the user's current data rate requirement and the actual current cumulative data rate of the time slots currently assigned to the user. The user data rate requirement may further be a function of a quality of service (QoS) contracted for by the user. Thus, the assignment of the time slots within the frame is made dynamically and the number of time slots employed by a user is increased or decreased according to the user's current data rate requirements and the ability of the time slots already assigned to the user to meet those requirements.
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公开(公告)号：CA2314032A1
公开(公告)日：2001-01-27
申请号：CA2314032
申请日：2000-07-13
Applicant: LUCENT TECHNOLOGIES INC
Inventor： RUPP MARKUS , VISWANATHAN HARISH , NARAYANASWAMY SHANKAR , KRISHNAMOORTHY RAJEEV
Abstract: In a system in which the modulation scheme employed may change on a per-time - slot basis, a user's available data rate may change even if the user maintains th e same number of time slots, because the capacity of the user's time slots may change. If one or more such changes in modulation scheme occurs, the data rate available to th e user may no longer match his current data rate needs. Therefore, a method is disclose d for determining the number of time slots to assign to a user as a function of th e user's current data rate requirement and the actual current cumulative data rate of the tim e slots currently assigned to the user. The user data rate requirement may further b e a function of a quality of service (QoS) contracted for by the user. Thus, the assignment of the time slots within the frame is made dynamically and the number of time slots employed by a user is increased or decreased according to the user's current data rate requirements and the ability of the time slots already assigned to the user to meet those requirements.
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公开(公告)号：CA2260528A1
公开(公告)日：1999-08-26
申请号：CA2260528
申请日：1999-01-28
Applicant: LUCENT TECHNOLOGIES INC
Inventor： RUPP MARKUS
Abstract: An effective receiver is achieved for situations where the receiver is mobile, and may be traveling at relatively high speed, and where the receiver's internal demodulation oscillator causes a frequency offset, with processing that shares a common algorithm for both frequency offset and channel characteristics estimations. Specifically, the commonly employed algorithm, such as the LMS algorithm, computes an estimate of the frequency offset, and that very same algorithm is also used to estimate the channel characteristics. When the LMS algorithm is used, a frequency offset estimate can be derived from signals derived in the course of executing the LMS algorithm. A frequency compensation factor is then developed and applied to the incoming signal to create a signal that that not have an appreciable frequency offset. That signal is then applied to a process that also employs the LMS algorithm, in combination with a detection algorithm, such as, for example, the Viterbi algorithm, to recover from the incoming signal the information signals that had been encoded into the incoming signals.
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公开(公告)号：DE60036837D1
公开(公告)日：2007-12-06
申请号：DE60036837
申请日：2000-07-17
Applicant: LUCENT TECHNOLOGIES INC
Inventor： KRISHNAMOORTHY RAJEEV , NARAYANASWAMY SHANKAR , RUPP MARKUS , VISWANATHAN HARISH
Abstract: In a system in which the modulation scheme employed may change on a per-time-slot basis, a user's available data rate may change even if the user maintains the same number of time slots, because the capacity of the user's time slots may change. If one or more such changes in modulation scheme occurs, the data rate available to the user may no longer match his current data rate needs. Therefore, a method is disclosed for determining the number of time slots to assign to a user as a function of the user's current data rate requirement and the actual current cumulative data rate of the time slots currently assigned to the user. The user data rate requirement may further be a function of a quality of service (QoS) contracted for by the user. Thus, the assignment of the time slots within the frame is made dynamically and the number of time slots employed by a user is increased or decreased according to the user's current data rate requirements and the ability of the time slots already assigned to the user to meet those requirements.
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