Patents by Inventor Nidham Ben Rached

Nidham Ben Rached has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7197023
    Abstract: The blocks to be sent on one or more physical channels for packet mode transmission pertain to several temporary block flows to terminals. The terminals are distributed into several subscription classes corresponding to various priority levels and each associated with a throughput restriction parameter. Transmission throug hputs allocated to the flows as a function of transmission throughputs respectively requested during the creation of the flows and restriction parameters associated with the subscription classes are determined. At least one traffic channel supported by a physical channel is allotted to each new flow created. For each send period on a physical channel, a flow to which a traffic channel supported by this physical channel is allotted, is selected with the aid of the values of the transmission throughputs allocated, so as to send a block of the selected flow in the course of said period.
    Type: Grant
    Filed: May 30, 2002
    Date of Patent: March 27, 2007
    Assignee: Nortel Networks Limited
    Inventors: Nidham Ben Rached, Jean-Louis Dornstetter
  • Patent number: 6904107
    Abstract: A method of estimating a communication path formed of a plurality of channels, the method necessitating an estimate of the impulse response C1, C2, . . . , Cn of the channels, including the following steps of (1) acquiring a space statistic of the transmission path, and (2) establishing a corrected impulse response (C1, C2, . . . , Cn) at least by weighting the impulse responce estimates (C1, C2, . . . , Cn) by the space statistic and an estimate of the additive noise (N01, N02, . . . , N0n) of the channels.
    Type: Grant
    Filed: April 10, 1998
    Date of Patent: June 7, 2005
    Assignee: Nortel Matra Cellular
    Inventors: Nidham Ben Rached, Jean-Louis Dornstetter
  • Publication number: 20050118993
    Abstract: A cellular network infrastructure has radio network controllers and fixed transceivers serving respective cells. The proposed method of controlling radio resources assigned to a communication between a mobile terminal and such infrastructure comprises measuring parameters of respective propagation channels between the mobile terminal and a number of fixed transceivers. Report messages indicating at least some of the measured parameters are transmitted to the radio network controller to be processed. The measured parameters indicated in the report messages for at least one fixed transceiver include data representing a time variability of a power level received on the channel between the mobile terminal and this fixed transceiver.
    Type: Application
    Filed: February 18, 2003
    Publication date: June 2, 2005
    Inventors: Pierre Roux, Thierry Lucidarme, Nidham Ben Rached
  • Patent number: 6850562
    Abstract: For processing samples of a signal received via a channel represented by an impulse response of W?1 coefficients, the method comprises: determining the W roots of the Z-transform of the channel impulse response; producing an intermediate signal by equalizing the received signal by a zero-forcing method or the like based on an impulse response whose Z-transform is a Z?1 polynomial of degree W-p having as roots those of the W roots which are furthest from the unit circle of the complex plane; and then obtaining estimations of the transmitted signal symbols by applying a Viterbi-type equalization method or the like based on an impulse response whose Z-transform is a Z?1 polynomial of degree p having as roots those of the W roots which are nearest to the unit circle.
    Type: Grant
    Filed: September 2, 1999
    Date of Patent: February 1, 2005
    Assignee: Nortel Networks S.A.
    Inventors: Jean-Louis Dornstetter, Nidham Ben Rached, Corinne Bonhomme
  • Publication number: 20050002476
    Abstract: Data blocks to be received each comprise a header and a data field including respectively first and second codes for error detection. The decoding of a signal segment received having first and second portions corresponding respectively to the header and to the data field of a block gave rise to a verification of the first code in the first portion. If the first code is correct, a check is made to verify whether the second portion of the decoded signal has a second correct code. A data block is considered to be detected either in the presence of first and second correct codes, or in the presence only of a first correct code when a data likelihood criterion, evaluated during the decoding of the second portion of the signal, is fulfilled.
    Type: Application
    Filed: April 22, 2004
    Publication date: January 6, 2005
    Inventors: Nidham Ben Rached, Stephane Cayla, Arnaud De Lannoy
  • Publication number: 20040266472
    Abstract: The radio network controller estimates respective attenuation ratios of radio signals received by a terminal from transmitters of an active set.
    Type: Application
    Filed: June 3, 2004
    Publication date: December 30, 2004
    Applicant: NORTEL NETWORKS LIMITED
    Inventors: Nidham Ben Rached, Thierry Lucidarme
  • Publication number: 20040247053
    Abstract: The method seeks detection of a signal burst transmitted on the initiative of a sender on a radio channel listened to by a receiver system. The burst transmitted represents a predetermined digital sequence. Channel parameters representing a statistical behaviour of the radio channel are estimated and a detection magnitude is evaluated on the basis of the estimated channel parameters and of a correlation between a signal received at the receiver system and the predetermined digital sequence. The detection magnitude is compared with an adaptive detection threshold to decide whether the signal burst is detected.
    Type: Application
    Filed: November 21, 2003
    Publication date: December 9, 2004
    Applicant: NORTEL NETWORKS LIMITED
    Inventors: Nidham Ben Rached, Thierry Lucidarme
  • Publication number: 20040196793
    Abstract: Parameters for the propagation channels between each mobile terminal (14, 14A, 14B) and several fixed transceivers (13) are measured and a report message transmitted to a radio network controller (12), indicating at least one part of the measured parameters. The ratio network controller processes the report messages. The parameters measured for each fixed transceiver are a propagation profile, including at least one propagation path associated with a reception energy and the parameters given in the report messages for at least one transceiver, comprise data on the energetic distribution in the propagation profile, taken into account by the radio network controller in processing.
    Type: Application
    Filed: January 5, 2004
    Publication date: October 7, 2004
    Inventors: Thierry Lucidarme, Nidham Ben Rached, Pierre Roux
  • Publication number: 20040179578
    Abstract: In a spread spectrum digital radiocommunication receiver, a first estimate of a symbol transmitted by a sender is calculated by applying to a radio signal received a processing taking into account a number N of propagation paths from the sender, a parameter of reliability of the first estimate is evaluated, and when the reliability parameter evaluated does not satisfy a confidence criterion, a second estimate of the symbol is calculated by taking into account at least one (N+1)-th propagation path from the sender in the processing applied to the radio signal received.
    Type: Application
    Filed: February 9, 2004
    Publication date: September 16, 2004
    Applicant: NORTEL NETWORKS LIMITED
    Inventors: Nidham Ben Rached, Thierry Lucidarme
  • Publication number: 20040137850
    Abstract: The method seeks a high-performance detection of a signal burst transmitted on the initiative of a sender on a radio channel listened to by a receiver system. The transmitted burst represents a predetermined digital sequence, serving for example to request access to a radio system or to ensure the synchronization of a radio interface. Channel parameters representing a statistical behavior of the radio channel are estimated and a detection magnitude is evaluated on the basis of the estimated channel parameters and of a correlation between a signal received at the receiver system and the predetermined digital sequence. The estimated channel parameters comprise moments of order greater than 2 of the gain on the radio channel.
    Type: Application
    Filed: November 20, 2003
    Publication date: July 15, 2004
    Applicant: NORTEL NETWORKS LIMITED
    Inventors: Thierry Lucidarme, Nidham Ben Rached
  • Publication number: 20040127175
    Abstract: Several versions of the radio signal are transmitted with different polarizations from a first station to a second station. The respective transmission powers of these versions of the radio signal are adaptively controlled according to measurements carried out by the first station on signals transmitted by the second station.
    Type: Application
    Filed: August 21, 2003
    Publication date: July 1, 2004
    Applicant: NORTEL NETWORKS LIMITED.
    Inventors: Thierry Lucidarme, Nidham Ben Rached
  • Patent number: 6757339
    Abstract: A method of estimating the sequence of transmitted symbols in a digital communication system is provided. By assuming that the transmitted symbols have a zero mean and a covariance matrix given by an identity matrix, as is the case in an EDGE communication system, the solution to the minimization of the expectation value of ∥{circumflex over (s)}−s∥2 always allows a lower triangular matrix to be found through Cholesky decomposition. The lower triangular matrix allows an efficient block decision-feedback sequence estimation to be carried out. The method is no more complex than the zero-forcing block decision-feedback sequence estimation technique, yet a solution always exists and performance is improved over the zero-forcing method.
    Type: Grant
    Filed: July 24, 2000
    Date of Patent: June 29, 2004
    Assignee: Nortel Networks Limited
    Inventors: Tharmalingam Ratnarajah, Radde Majeed, Nidham Ben Rached
  • Patent number: 6754264
    Abstract: Discrete symbols of transmitted signals, forming part of the components of a vector D of size N, are estimated from a vector Y of L digital samples of a received signal. The vector Y may be broken down into Y=AD+YN, where A is a matrix of size L×N previously determined from measurements of at least one transmission channel reply and YN represents a vector of L noise samples. The method includes determining an upper triangular matrix T of size N×N and a vector Z of size N such that the quadratic criteria ∥TX−Z∥2 and ∥AX−Y∥2 are minimal for the same vector X of size N, and dividing the vector Z and the matrix T into blocks so as to operate a minimisation of the quadratic criterion block by block along the diagonal of matrix T.
    Type: Grant
    Filed: September 12, 2000
    Date of Patent: June 22, 2004
    Assignee: Nortel Matra Cellular
    Inventors: Nidham Ben Rached, Sarah Boumendil
  • Publication number: 20040097196
    Abstract: The invention concerns a method for evaluating the energy level of a signal received via a radio interface between radiocommunication stations which consists in obtaining successive measuring samples (Ck) depending on the signal energy, and in calculating an average (C) of said samples. The averaging of the measuring samples is carried out with an averaging duration (T) depending on a service in the context of which the received signal is inscribed, and preferably also an estimation of the moving speed (v) of one of the stations.
    Type: Application
    Filed: May 8, 2003
    Publication date: May 20, 2004
    Inventors: Nidham Ben Rached, Thierry Lucidarme, Arnaud De Lannoy
  • Publication number: 20040087343
    Abstract: Method of allocating communication codes to channels set up in respect of mobile terminals in communication in a cell of a radiocommunication system, in which the cell is served by a fixed station having means of adjustment of send/receive parameters defining a respective antenna pattern in respect of each mobile terminal in the cell, in which the allocated communication codes form part of a set of codes some at least of which are mutually orthogonal. In response to channel setup or reconfiguration request in respect of a first mobile terminal in the cell, the allocation to the said channel of a code nonorthogonal to at least one code of the set already allocated to another channel set up in respect of a second mobile terminal in the cell is conditionally admitted, as a function of a comparison between the send/receive parameters determined in respect of the first and second terminals.
    Type: Application
    Filed: September 3, 2003
    Publication date: May 6, 2004
    Applicant: NORTEL NETWORKS LIMITED
    Inventors: Thierry Lucidarme, Nidham Ben Rached
  • Publication number: 20040028155
    Abstract: The invention concerns a method for treating a baseband digital signal at the output of an adapted filter (9) and at the input of a channel equalizer (13), which consists in subjecting said signal to a whitening filter (10) whereof the coefficients for each signal block are estimated taking into account the interfering signals in the frequency band of the useful signal and in one or several adjacent bands. That process consists in projecting an autocorrelation vector calculated from the signal block received from different directions corresponding to predetermined correlation vectors related to the useful signal, to signals possibly present in the adjacent bands and to thermal noise. The whitening filter coefficients are then deduced from the sum of projected vectors, taking into account the useful signal energy if the latter has not been removed before calculating the autocorrelations.
    Type: Application
    Filed: August 8, 2003
    Publication date: February 12, 2004
    Inventors: Jean-Louis Dornstetter, Nidham Ben Rached
  • Publication number: 20040014444
    Abstract: Radio links support signals, representing data blocks composed of symbols, transmitted between base stations and mobile stations by applying a transmission errors protection scheme selected from several specified protection schemes. Some at least of said stations communicate to a control unit measurement values relating to errors observed in the reception of symbols transmitted, and the control unit consults at least one lookup table to adaptively select the protection scheme applied to each radio link as a function of the measurement values communicated in relation to said link. For at least one of the protection schemes, statistical parameters relating to errors observed in the reception of blocks transmitted by applying said protection scheme are estimated. The estimated statistical parameters are processed so as to update the lookup table.
    Type: Application
    Filed: May 30, 2003
    Publication date: January 22, 2004
    Applicant: Nortel Networks Limited
    Inventors: Nidham Ben Rached, Stephane Cayla
  • Patent number: 6671313
    Abstract: The invention relates to a method of estimating a transmission channel from a signal (S) received by that channel. The received signal corresponds to a transmitted training sequence, and the method includes the following steps: acquiring a statistic of the transmission channel, establishing an estimate (Xp) of the impulse response of the channel weighted by the statistic of the channel of the received signal (S).
    Type: Grant
    Filed: February 14, 2000
    Date of Patent: December 30, 2003
    Assignee: Nortel Matra Cellular
    Inventors: Nidham Ben Rached, Jean-Louis Dornstetter
  • Publication number: 20030138064
    Abstract: The invention concerns a method for estimating an offset between a radio frequency used by a receiver to form a baseband signal from a radio signal segment received through a communication channel and a carrier frequency of the radio signal of the segment. The radio signal segment is produced by a transmitter from a block of modulating symbols including at least two sequences of predefined symbols separated by information symbols. It consists in generating a frequency offset estimate on the basis of at least two sequences of baseband signal samples corresponding to two sequences of the block predefined symbols.
    Type: Application
    Filed: October 22, 2002
    Publication date: July 24, 2003
    Inventors: Zied Malouche, Nidham Ben Rached
  • Publication number: 20030026204
    Abstract: The blocks to be sent on one or more physical channels for packet mode transmission pertain to several temporary block flows to terminals. The terminals are distributed into several subscription classes corresponding to various priority levels and each associated with a throughput restriction parameter. Transmission throughputs allocated to the flows as a function of transmission throughputs respectively requested during the creation of the flows and restriction parameters associated with the subscription classes are determined. At least one traffic channel supported by a physical channel is allotted to each new flow created. For each send period on a physical channel, a flow to which a traffic channel supported by this physical channel is allotted, is selected with the aid of the values of the transmission throughputs allocated, so as to send a block of the selected flow in the course of said period.
    Type: Application
    Filed: May 30, 2002
    Publication date: February 6, 2003
    Inventors: Nidham Ben Rached, Jean-Louis Dornstetter