Juniper Networks, Inc.

Sequans Communications Limited

Alcatel

Fabien Buda

Hikmet Sari

Ambroise Popper

Emmanuel Lemois

Bertrand Debray

Serdar Sezginer

Bertrand Muquet

Juing Fang

Cyril Bertrand

Josephine Hus

Weixiao Xu

Amélie Duchesne

Jo&euml;l Richard

Joséphine Hus

A cell search method in a multiple carrier wireless network includes a step of trying to select, among a list of candidate couples [carrier frequency; bandwidth], at least one candidate associated with at least one cell of the multiple carrier wireless network. The cell search method includes: a step of obtaining and ordering an initial list of possible candidate couples [carrier frequency; bandwidth] according to the multiple carrier wireless network; a step of reducing the initial list, delivering a reduced list, the reduced list including only candidates compatible with a predetermined communication mode of the multiple carrier wireless network, through a differential cross correlation of the candidate couples [carrier frequency; bandwidth] of the initial list; a cell search step in which a cross-correlation is performed by testing all time/frequency hypothesis for at least one candidate of the reduced list of candidates, delivering synchronisation information.

Cell search method for a downlink channel of an OFDMA transmission system

A method of canceling co-channel interference of a signal received by a mobile station having at least two receiving antennas, in a cellular OFDMA-TDD communication network having a serving base station and at least one interfering base station. The signal is a result of a serving signal transmitted by the serving base station which is distorted by at least one interfering signal transmitted by the interfering base station. The serving signal is transmitted with a first modulation scheme and the interfering signal is transmitted with a second modulation scheme. The method includes: a channel estimation phase delivering channel estimations of the serving signal and the interfering signal; and a MIMO detecting phase, detecting symbols by using the channel estimations of the serving signal and the interfering signal. The MIMO detection phase is realized using a non-linear method which uses the first modulation scheme and the second modulation scheme.

Method of exploitation of co-channel interference, apparatus and computer program

An embodiment of a method for transmitting data through at least a channel in a wireless communication system, the method comprising at least the steps of:

Method for transmitting a sequence of symbols for exploiting transmit diversity

A method and apparatus are provided for allocating and transmitting groups of subcarriers, called tiles, between a plurality of transceiver antennas. The method includes receiving at least one downlink signal by a subscriber station transceiver through at least one of the plurality of subscriber station antennas, characterizing a received signal of at least one downlink signal over multiple subcarriers, and allocating tiles for uplink transmission through at least one of the plurality of transceiver antennas. The tiles allocation is based on the characterized received signal of the at least one downlink signal over multiple subcarriers and is based on a required power Ptx for uplink transmission compared with a maximum power P that each of the plurality of the transceiver antennas can emit.

Tile allocation method

The TDMA receiver comprises a control unit for allocating to each of a plurality of transmitters time intervals during which the transmitter is allowed to transmit signals towards the TDMA receiver, a receiving unit for receiving an incoming signal resulting from the multiplexing of different signals which are output by the plurality of transmitters during the allocated time intervals and in the predetermined frequency band, the incoming signal thus consisting, in the predetermined frequency band, of a TDM signal, a processing unit for extracting and processing the TDM signal, and a spectrum determination unit for determining the spectrum of the incoming signal. The control unit is designed to synchronize the operation of the spectrum determination unit as a function of the time intervals allocated to the transmitters for the determination of the spectrum of the incoming signal in the predetermined frequency band.

TDMA receiver

The present invention teaches a compact and highly integrated multiple-channel digital tuner and receiver architecture, suitable for widespread field deployment, wherein each receiver demodulator channel may be remotely, automatically, dynamically, and economically configured for a particular cable, carrier frequency, and signaling baud-rate, from an option universe that includes a plurality of input cables, a plurality of carrier frequencies, and a plurality of available baud-rates. A multiple coax input, multiple channel output, digital tuner is partitioned into a multiple coax input digitizer portion and a multiple channel output front-end portion. The digitizer portion consists of N digitizers and accepts input signals from N coax cables and digitizes them with respective A/D converters. The front-end portion consists of M front-ends and provides M channel outputs suitable for subsequent processing by M respective digital demodulators. In a first clock domain, a fixed predetermined A/D sampling rate is chosen to provide oversampling of the inputs by a common integer multiple of all the symbol rates of interest. A plurality other clock domains operate at selectable sub-multiples of the first domain as required to deliver a constant number of symbol samples at the output of each front-end. At the input to each of the M front-ends is a respective input selector coupled to each of the N streams of digitized input data followed by a digital signal scaler that dynamically scales the selected incoming stream of digitized input data as a function of the signal power of the channel's associated carrier.

Multiple input, multiple output channel, digital receiver tuner

The invention provides a device (D) for reducing ingress noise in a digital signal, comprising a noise predictor () for predicting an amount of ingress noise in the digital signal (s) based on past samples of the ingress noise, and a subtractor () for subtracting the predicted amount of ingress noise from the digital signal. Channel distortion is compensated for by a noise-independent equalizer (), such as a ZF equalizer, placed upstream of the noise predictor (). The device (D) may be incorporated, for example, in a cable modem termination system (CMTS) of an hybrid fiber/coax (HFC) network.

Ingress noise reduction in a digital receiver

The invention provides a device for reducing ingress noise in a digital signal, comprising a noise predictor for predicting an amount of ingress noise in the digital signal based on past samples of the ingress noise, and a subtractor for subtracting the predicted amount of ingress noise from the digital signal. Channel distortion is compensated for by a noise-independent equalizer, such as a ZF equalizer, placed upstream of the noise predictor. The device may be incorporated, for example, in a cable modem termination system (CMTS) of an hybrid fiber/coax (HFC) network.

A method of synchronizing a base station of a wireless communication system and a subscriber communication equipment located in the coverage area of the base station by compensating a sampling frequency offset in the subscriber equipment by interpolating input and/or output signals of a radio frequency part of the communication equipment to generate samples corresponding to the original symbol timing of the base station, and compensating the carrier frequency offset from the estimate of the sampling clock error.

Method and system for synchronizing a base station of a wireless communication system and a subscriber communication equipment

The invention provides a spread-spectrum transmission system with multiple carrier modulation in which the signals for transmission over each of the subcarriers are filtered prior to being transmitted over the subcarrier, thereby making it possible on reception to synchronize the various subcarriers in time, and in which each subcarrier carries a plurality of chips that result from spreading a single symbol. With coherent modulation, the number of chips resulting from spreading a single symbol and transmitted over each subcarrier is selected so as to enable the various subcarriers to be put into phase alignment by recombining the chips coming from the same symbol on each subcarrier. With differential modulation, the transmission over each subcarrier of chips resulting from spreading a single symbol provides resistance to jamming by limiting recombination losses because of the differential modulation.

Spread-spectrum transmission system with filtered multi-carrier modulation

A method of soft input to soft output decoding of a word of a block linear code of dimension k and length n received from a transmission channel is provided, including generating a list of firm words ( ) of the code close to the received code word ( ) by coding a list of k-tuplets obtained by firmly approximating components of the received word and changing the least likely components, and calculating the j component of the output soft word as the difference between the metrics of the closest generated code word and the closest generated code word having an opposite j component, or, failing this, the farthest generated code word. Also provided is a method of iterative decoding of a product code word received on a transmission channel using the soft input to soft output decoding method. It rapidly and efficiently decodes product code words without an algebraic decoder.

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Paris, France

Fabien Buda