UniversitÉ Libanaise

UniversitÉ Saint-Esprit De Kaslik

Institut Mines-telecom

Institut Mines-telecom / Telecom Bretagne

Orange

Institut Mines Telecom-imt Atlantique-bretagne-pays De La Loire

Institut Mines-telecom / Telecom

Groupe Des Ecoles Des Telecommunications/ Ecole Nationale Superieure De Telecommunications De Bretagne

Charbel Abdel Nour

Catherine Douillard

Jérémy Nadal

Amer Baghdadi

Marie-Rita Hojeij

Joumana Farah

Hao Lin

Naila Lahbabi

Ronald Edicson Garzon Bohorquez

Rami Klaimi

A device configured to perform a stage of circular convolutions in an Overlap-Save Filtered-Bank Multicarrier Communication (OS-FBMC) or Overlap-Save-Block FBMC (OSB-FBMC) receiver and the corresponding method, the stage of circular convolutions comprising P circular convolutions operated between subsets of input samples and frequency domain responses of a frequency shifted version of a prototype filter associated to an FBMC modulation having Ccoefficients, with P an integer greater than one, the device comprising at least one Finite Impulse Response filter implemented in the form of a transposed direct filter having at least C−1 taps numbered p=−Δ+1 to p=Δ with wherein the multiplier coefficient of each tap p within the set of taps−Δ+1; 0has an equal absolute value to the multiplier coefficient of tap (1−p). An FBMC equalization and demodulation unit or an FBMC receiver comprising the device.

Optimised circular convolutions stage for OS/OSB FBMC receivers

A method for generating a signal, including turbo-coding a set of information symbols delivering, on the one hand, the information symbols and, on the other hand, redundancy symbols. The turbo-coding implementing, to obtain the redundancy symbols: an encoding of the set of information symbols by a first encoder, an interleaving of the set of information symbols, and an encoding of the set of information symbols interleaved by a second encoder. The turbo-coding also implements a bijective transformation of the information symbols, implemented before and/or after the interleaving, the transformation modifying a value of at least two of the information symbols prior to the coding of the information symbols by the first and/or the second coder.

Method for generating a signal by means of a turbo-encoder, and corresponding device and computer program

A method and system for assigning power to sub-bands in a multiple access communications system, where users are assigned iteratively to sub-bands, and at each iteration a provisional partial power budget is determined for the subset of sub-bands comprising the sub-bands to which users have been assigned in the present time slot and the sub-band under consideration in the sequence, where the fraction of the total available power determined as the provisional partial power budget corresponds to the fraction of the number of sub-bands in the subset from the total number of sub-bands to be assigned, and the provisional power allocation for the sub-band under consideration is obtained by performing a waterfilling distribution of the provisional partial power budget amongst the subset of the sub-bands, based on the channel gain of the users already assigned to sub-bands in the present time slot.

Method and apparatus for power distribution to sub-bands in multiple access communications systems

A mechanism is presented for attributing users to one or more of a plurality of sub-bands in a multiple access communications system, wherein in an initial assignment phase, a first user is selected for a sub band, for example on the basis of a user priority. Users having complementary channel gains to that of the first user are identified, and then a second sub-band user maximizing a performance metric reflecting the achieved throughput, and/or fairness across users, is selected to accompany the first user on that sub-band. The initial assignment phase may terminate once all users have been assigned to a sub-band once. After the first phase is complete, the first user for each sub-band may be the user whose achieved total throughput is furthest from a target throughput defined for that user, wherein each user is assigned to the remaining sub-band to which no first user is currently attributed offering the highest channel gain for that user. Mechanisms for determining user priority, making provisional and definitive power allocations, and performance metrics are proposed.

Method and apparatus for user distribution to sub-bands in multiple access communications systems

A method and device to modulate an FBMC/OQAM signal, the device comprising at least one QAM mapper mapping a binary stream into complex symbols, a first and a second transmission chain. Each chain comprises: a precoder transposing respective sets of symbols into frequency domain real/imaginary samples, a phase rotator applying a phase quadrature keying to said samples, an FBMC modulator to modulate the output of the phase rotator into an FBMC symbol. The device further comprises an adder of the output of the first transmission chain with a delayed output of the second transmission chain, and is configured to insert guard interval sequences into the binary stream or into the symbols processed by the precoders. A corresponding radio communication equipment, computer program and readable medium is provided.

Pseudo-guard intervals insertion in an FBMC transmitter

A system and method for assigning users to a particular sub band in a given time slot in a NOMA system, where whichever pair of users corresponds to the smallest 'candidate pair user throughput deviation value', reflecting the aggregate of the respective difference between the average throughput across all users (K) and the known throughput of each of the two users under consideration (kk), and each user attributed to a sub-band other than the selected sub-band. User pairs for consideration may consider all possible pairs, or may be limited to candidate pairs satisfying together, or comprising one or both users who satisfy a criterion such as channel gain, distance to a target, throughput or a combination of some or all of these factors. The power allocated to each sub-band may be attributed by a waterfilling algorithm.

A method of determining a performance metric for a selection of a first user and a second user among a set of candidate users for attribution to a sub-band in a multiple access communications system based on Non-Orthogonal Multiple Access (NOMA), is provided wherein the first user (k) and the second user (k) are selected as the pair of candidate users corresponding to an extremum of the ratio between a first term reflecting the total throughput achievable by any pair of the candidate users assigned to the sub-band (s) under consideration, and a second term reflecting the known throughput achieved by that same pair of candidate users over a predetermined preceding period. Implementations include a method of determining a performance metric is presented for attributing users to one or more of a plurality of sub-bands in a multiple access communications system, wherein in an initial assignment phase for a specific sub-band, a first user is selected for that band on the basis of one or more criteria such as user priority. Then a second sub-band user maximizing or minimizing the performance metric.

User distribution to sub-bands in multiple access communications systems

An FBMC equalization and demodulation unit and corresponding method to process an FBMC signal includes FBMC symbols, each FBMC symbol comprising data mapped over M subcarriers, oversampled by a factor K, filtered by a prototype filter and transposed in the time-domain, comprising: a frequency domain transposition unit, configured to transpose a block of P*KM samples comprising at least one FBMC symbol into frequency domain samples, where P is an integer greater than one, an equalizer unit configured to multiply the frequency domain samples by one or more coefficients computed from a propagation channel estimate, at least one circular convolution unit, configured to perform P circular convolutions between subsets of the equalized samples and a frequency domain response of a frequency shifted version of the prototype filter, and adders, to sum corresponding outputs of each of the P circular convolutions.

Overlap-save FBMC receiver

An encoder architecture for UF-OFDM is provided, in which samples are first processed sub-band wise, and then resorted for sub-carrier-wise processing. The sub-carrier processing may comprise separate processing for the two extremity parts of the base band signal corresponding to the transient state of the UF-OFDM data stream and for a core part of the base band signal corresponding to the non-transient state of the UF-OFDM data stream, and then concatenated to obtain a UF-OFDM data stream. In certain embodiments a first extremity part of the base band signal corresponding to the transient state of the UF-OFDM data stream is calculated directly, and the other extremity part inferred from the core part and the first extremity part. The core and extremity part processors may be implemented with filters adapted to multiply each sample by a respective filter coefficient. Modifying these coefficients can introduce a frequency shift or convert the encoder for OFDM encoding.

Digital encoder and method of encoding

A mechanism for attributing users to a plurality of sub bands in a time slot t in a multiple access communications system, said method comprising assigning a combination of users to a sub band on a Proportional Fairness basis, that is to say whichever combination of users maximizes a Proportional Fairness performance metric for that channel, where the performance metric is weighted by a weighting factor reflecting the difference for that user between a target throughput and a projected throughput.

Method and apparatus for user distribution to sub bands in NOMA systems

A method for generating a multicarrier signal formed by a temporal succession of multicarrier symbols, implementing the following steps for generating at least one block of multicarrier symbols: coding a set of information elements delivering a set of coded elements; puncturing a first sub-set of coded elements of the set of coded elements, according to a first puncturing pattern, delivering a first sub-set of punctured coded elements; puncturing a second sub-set of coded elements of the set of coded elements, complementary to the first sub-set, according to a second puncturing pattern, delivering a second sub-set of punctured coded elements; mapping, onto at least one complex symbol, of the punctured coded elements of the first and second sub-sets of punctured coded elements; and generating the block of multicarrier symbols from said at least one complex symbol.

Method for producing a multi-carrier signal, device, and corresponding computer program

A receiver for Filter Bank Multicarrier frequency spread signals such as FBMC, FBMC/OQAM, OFDM, comprises a linear phase rotation module adapted to introduce a linear phase rotation to a received time domain signal, a discrete Fourier transform and a Finite Impulse response digital filter. The coefficients of the digital filter define a shift of the frequency response of the prototype filter of the receiver, and the coefficients of the digital filter are fixed so as to compensate the linear phase rotation introduced by the filter. The frequency shift introduced may be equal to the reciprocal of a power of two of the modulation sub carrier spacing.

Receiver architecture for linear modulation based communication systems

Power allocation in NOMA systems for example on the basis Proportional Fairness calculations depends on knowledge of user throughput on a specified sub-band, which implies that users have already been allocated to particular sub-bands. Meanwhile, maximum throughput can generally be achieved where there is the greatest possible difference in transmission power for the users on a given sub-band, so that optimal allocation of users to sub-bands requires knowledge of the power available for each user. A mechanism is proposed based on iteratively applying a waterfilling algorithm to distribute power across a progressive subset of sub-bands to provisionally distribute the power budget across that subset of sub-bands, where at each iteration the water filling algorithm is carried out for each possible combination of users assignable to the newly considered sub-band using a floor for that sub band proportional to the reciprocal of the square of the highest channel gain value of any user in that combination, and calculating a throughput for that combination with the corresponding power attribution, whereby the combination retained for the next iteration (with an additional sub-band) is whichever gives the highest throughput. This process is thus repeated until users are assigned to all sub-bands, whereupon power allocations from the last iteration are definitive.

Method and apparatus for power and user distribution to sub-bands in NOMA systems

A method of designing a digital filter for example for use in an FBMC/OQAM telecommunications system, with a target overlapping factor and meeting a specified signal to interference ratio is described, whereby a candidate filter design defined by an impulse response, satisfying the Nyquist criterion and having an overlapping factor higher than the target is selected, and the time and frequency coefficients of its impulse response inverted to define a new filter design; and truncating the impulse response defining said new filter design to the minimum number of coefficients achieving said specified signal to interference ratio.

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Brest, France

Charbel Abdel Nour