Sequans Communications Limited

Sequans Communications Sa

Serdar Sezginer

Hikmet Sari

Yang Liu

Imran Latif

Fabien Buda

Bertrand Muquet

Moussa Abdi

Aymane Hamahmy

Alain Kouioumdjian

Thomas Winiecki

Ioannis Xirouchakis

Guillaume Vivier

Serguei Burykh

Krzysztof Walczak

Weixiao Xu

Van Minh Nguyen

Youssef El Hajj Shehadeh

Youssef El Hajj Shehaden

A method of selecting an intermediate frequency, IF, for use with a low-IF receiver, the method comprising determining a first frequency as the central frequency of the system bandwidth of the communication scheme used by the low-IF receiver, determining a second frequency as the central frequency of the bandwidth of the wanted signal to be received, selecting the sign of the IF to be used based on the first and second frequencies.

Low-IF receiver

A method of configuring an error correction engine, the method comprising determining the frequency of operation of the error correction engine, determining the size of the code to be error corrected, determining the time permitted in which to error correct the code, and based on the determining steps, configuring the number of active error correction processes within the error correction engine to be used to error correct the code.

Flexible error correction

A method of synchronizing uplink between a UE and a cell, the method comprising determining PRACH capabilities of the UE, determining a negative timing offset for use with the transmission of at least one PRACH signal, determining an order for utilizing the negative timing offset, transmitting from the UE, at least one PRACH signal from a group of N PRACH signals, each of the at least one PRACH signals having a predetermined power level and transmitted by the UE at a time based on the negative timing offset, the order, and the PRACH capabilities of the UE.

Range extension of LTE cells

A method of spatially multiplexing data comprising a signal vector, the method comprising selecting first and second modulation schemes for the data transmission wherein the second modulation scheme is an interpolation in the plane of the first modulation scheme; and further wherein the modulation schemes are selected so as to maintain the same minimum Euclidean distance between vectors comprising the first and second modulation schemes as the minimum Euclidean distance within the first and second modulation schemes; and selecting a plurality of antennae, each of the plurality to concurrently transmit respective symbols of the signal vector.

Enhanced spatial multiplexing

A computer implemented method for providing OTDOA timing information comprising defining an FFT window pair for estimating a value of reference signal time difference 'RSTD' for at least one base station and a reference cell, receiving a PRS from the at least one base station and the reference cell, executing an FFT per OFDM symbol of the PRS for each FFT window of the FFT window pair, obtaining a first FFT output vector per OFDM symbol of each FFT window, for each first output vector, descrambling tones corresponding to the known position of the PRS, wherein all other tones are set to zero, combining vectors based on respective first FFT output vectors, executing an iFFT to convert to the time domain; and calculating an estimated value of reference signal time difference 'RSTD' for the at least one base station and the reference cell.

OTDOA in LTE networks

A computer implemented method of providing RSTD data comprising receiving an uncertainty window centered around an expected RSTD value, determining the PDP of each reference OFDM symbol within the uncertainty window, obtaining a main PDP by calculating a parameter indicative of signal quality for each determined PDP, the main PDP having the highest signal quality, obtaining a preceding PDP of the Main PDP, obtaining a succeeding PDP of the Main PDP, determining PDP metrics comprising, determining a channel metric for each of the main, preceding and succeeding PDPs, determining a channel main tap for each of the main, preceding and succeeding PDPs, determining a delay estimate for each of the main, preceding and succeeding PDPs, wherein if the main PDP is a combined PDP, performing coherence testing on the PDP metrics to detect any ambiguity in the delay estimate of the main PDP, and correcting any ambiguity.

Ambiguity resolution in positioning measurements

A method of transmitting data comprising choosing a transmit modulation scheme of the transmission, choosing a transmit parameter of the transmission, transmitting the data stream according to the chosen transmit modulation and transmit parameter such that data of the data stream is transmitted by the modulation scheme and the choice of transmit parameter.

Enhanced modulation

A method and apparatus are provided for cancelling interferences of a received MIMO RF signal. The method includes: receiving a signal y; an initial step of obtaining, from the received signal y, at least one data representative of the received signal, called decoded data; computing the decoded data as a function of at least one predetermined criterion, delivering feedback data and a feedback decision; and, as a function of the feedback decision, at least one iteration of the following steps: constructing a set of feedback symbols from the feedback data; obtaining, from the set of feedback symbols, at least one data representative of a feedback decoded signal, called feedback decoded data; computing the at least one feedback decoded data as a function of the at least one predetermined criterion, delivering the feedback data.

Interference cancellation method with multiple data layer MIMO transmission

A method and apparatus for estimating a transmission channel in a receiver of an OFDMA signal formed by a plurality of carriers modulated by data elements and distributed in the time-frequency domain in successive symbols, the plurality of carriers including pilot carriers, modulated by reference data elements known by receivers. The method includes: receiving a signal comprising a series of n symbols covering at least one resource block; making an initial channel estimation by identifying the pilot carriers included in the series of n symbols; determining diagonal entries of p frequency domain channel matrices Gfor estimating the channel for at least x symbols among the n symbols, the x symbols being pilot symbols; determining, in the frequency domain, at least some non diagonal entries for each frequency domain channel matrix G of the n symbols from the determined diagonal entries of the x frequency domain channel matrices G.

Method for estimating a received signal and corresponding device

A channel estimation treatment method and device for obtaining binary data conveyed in a signal. The method includes: obtaining a current vector of channel estimates, each element of the current vector corresponding to an estimate of a subchannel; detecting, inside the current vector, at least one pilot symbol; splitting the current vector in at least two subvectors, at least one first subvector including channel estimates related to data symbols and/or pilots symbols and at least one second subvector including channel estimates related to null symbols; decoding the at least one first subvector, delivering at least one first treated subvector; modifying the at least one second subvector by assuming presence of pilot symbols in the at least one second subvector, delivering at least one second treated subvector; and calculating a new vector of channel estimates with the at least one first treated subvector and the at least one second treated subvector.

Iterative channel estimation method with compensated MMSE

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 channel estimating method is provided for a signal transmitted in an orthogonal frequency division multiplexing (OFDM) system, wherein an OFDM symbol of the signal has at least one null subcarrier set in its defined bandwidth. The method includes: obtaining at least one initial channel estimate over at least one OFDM symbol of a received signal; processing the at least one initial channel estimate for delivering at least one soft information in a form of a complete matrix; and updating the at least one initial channel estimate by performing a truncated singular value decomposition of a partial FFT matrix. The partial FFT matrix includes only the first Lcolumns and the rows Nof an FFT matrix of the complete matrix, the Nrows corresponding to modulated subcarriers of received signal, including data and pilot symbols and excluding the at least one null subcarrier, delivering an improved channel estimate.

Channel estimation method

An embodiment of a method for transmitting a sequence of symbols through at least a channel in a wireless communication system includes: forming a coding matrix with the sequence of symbols, each component of the coding matrix being a linear combination of two symbols among a first, a second, a third, and a fourth symbol (s, s, s, s), transmitting a first component and a second component of a first column and of a second column of the coding matrix through a first transmit antenna and a second transmit antenna at a first and a second time slot wherein the coding matrix is defined as a, b, c, d being complex numbers of modulus 1.

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