St-ericsson Sa

Ericsson Modems Sa

St-ericsson (france) Sas

Optis Circuit Technology, LLC

Telefonaktiebolaget Lm Ericsson (publ)

Oct Circuit Technologies International Limited

Andrea Ancora

Fabrizio Tomatis

Issam Toufik

Giuseppe Montalbano

Matthew Baker

Pierre Demaj

Laurent Noel

Dominique Brunel

Sébastien Aubert

Ahmet Bastug

Patrick Galili

Laurent Pilot

Sébastien Charpentier

Guiseppe Montalbano

Sébastian Aubert

A method permits a UE receiver to detect and report to the network a scrambling code collision (i.e., two neighbor cells transmitting with the same scrambling code while timing is aligned). The UE receiver decodes the PCCPCH's physical channel with all the associated broadcast information while a scrambling code collision at the UE is present. The UE reports SFN-SFN information to the network, to insure the UE mobility and then prepare the handover to a new detected cell. This process and a respective apparatus are usable in the presence of MIMO and further improve the detection of the scrambling code collision in the presence of MIMO.

P-CPICH scrambling code collision detection

A process selects a Precoding Matrix Index (PMI) in a Multiple In Multiple Out (MIMO) receiver used in a wireless communications system including a base station communicating with User Equipments (UE) through a downlink and uplink channel. The base station applies a precoding on the transmit symbol vector based on a matrix selected from a set of predefined matrices and identified by a PMI index computed by the UE and forwarded to the base station via the uplink. The process includes estimating the MIMO channel matrix H of a given set of resources blocks comprising received symbol vectors, estimating the variance &#x3c3;of the additive noise (AWGN), and computing for each particular matrix comprised within the set of predefined matrices a cost function representative of the orthogonality of the matrix MIMO channel matrix H. The process further includes comparing the values of the cost function and transmitting to the base station the index corresponding to the matrix corresponding to the best conditioned MIMO channel matrix according to the comparison of the values.

Precoding matrix index selection process for a MIMO receiver based on a near-ML detection, and apparatus for doing the same

A radio transceiver including&#x2014;an antenna () switch having a control lead (); &#x2014;a RF and front end circuit () coupled to said antenna switch and operating in at least one 2G mode and at least one 3G mode; &#x2014;a RF transceiver () coupled to said RF front end and operating in at least a first 2G and a second 3G mode; &#x2014;a baseband () communicating with a set of peripherals and external devices; The radio transceiver is characterized by the fact that it includes: &#x2014;control means () for controlling said antenna switch () in a isolated mode; &#x2014;an programmable adaptive filter controlled by said control means for the purpose of introducing at least one notch for eliminating one corresponding spur. The radio transceiver preferably includes means () for performing, under control of said control means () a FFT computation for the purpose of elaborating a representation, in the time domain, of the different spurs and/or jammers spoiling the received signal when in isolated mode.

Process for achieving spur mitigation in an integrated circuit including a wide band receiver

A Process for achieving slot synchronization of the P-SCH sequence in a UMTS communication system, involving the step of receiving () said signal including a synchronization sequence (P-SCH); performing a correlation () of each received sample with a known synchronization sequence (P-SCH) in order to generate a correlation profile; determining () the level of noise and computing a first threshold; suppressing () any peaks within said correlation profile having a magnitude inferior to said first threshold; detecting () the persistent local maximum peaks over a period of N slots; applying a predetermined mask positioned with respect to said persistent peaks and associated to at least one second threshold value distinctive from said first threshold.

Process for slot synchronization of the P-SCH sequence in a UMTS communication system and a receiver for the same

Process for canceling Intercarrier Interference in a OFDM receiver receiving OFDM blocks in presence of Doppler, comprising the steps of: receiving a OFDM block comprising N samples; applying a FFT for the purpose of generating N frequency domain representations composing the received signal (R); multiplying said received signal (R) by the hermitian value of the channel (H), with H being the channel estimate; applying on said received signal a preconditioned conjugate gradient algorithm based on a N&#xd7;N P preconditioner matrix; Characterized in that said preconditioner matrix is computed at follows: Formula (19) and formula (20), where formula (I) is a L&#xd7;PN selection matrix obtained by extracting a predetermined number (L) of rows from the identity matrix I, LFIR being a predetermined integer inferior to PN, with p corresponding to the basis expansion order chosen and N is the FFT size; formula (II) is equal to HF, with H being the frequency-domain channel matrix and F being the N&#xd7;N discrete-Fourier transform unitary matrix F; formula (III) is the N&#xd7;N identity matrix; formula (IV) is the varience of the noise; formula (V) is being the 1&#xd7;N vector containing 1 in n-th position and 0 elsewhere. 

Process for suppressing intercarrier interference in a OFDM receiver

A process for decoding a signal being representative of a Space Time or Frequency Block coding during two signaling periods (STBC) or two parallel channels (SFBC) is provided. The process receives an OFDM signal received from at least one antenna. The process also performs an OFDM demodulation in order to generate N frequency domain representations of the received signal. Then the process performs a decoding process on said OFDM demodulated signal and groups the received signal in word code, Y=(y, y), to represent the signal that was received during two signaling periods (STBC) or two parallel channels (SFBC). The word code is then decoded into a matrix after which a lattice reduction algorithm is applied to the matrix in order to transform the matrix into a reduced matrix having a near orthogonal vector. Then it performs a detection process on the reduced matrix to improve noise and interference immunity.

Process for decoding ALAMOUTI block code in an OFDM system, and receiver for the same

A process for cancelling inter-cell interference between neighboring cells in a synchronized OFDM communication system allowing communication between one User Equipment (UE) fitted with at least two antennas and one serving base station is provided. The process allows multi-antenna mobile receiver in a UE to receive downlink information from a base station that includes both information relating to proper communication with the base station and additional information that was received by the base station from a neighboring base station that provides interference data about another UE. The multi-antenna UE is adapted to use the downlink information in its receiver circuitry to cancel the interference from the other UE.

Process for inter-cell interference cancellation in a synchronized OFDM system, and apparatus for the same

A Method for estimating the channel in a Long Term Evolution (LTE) communication system, said method involving the step of extracting a Primary Synchronization Signal (PSS) from a received signal and further involving the step of spanning said PSS based Least Square (LS) channel estimation on the 64 sub-carriers so as to facilitate the MMSE channel estimation. Preferably, the spanning is performed by means of an interpolation of the particular sub-carriers which are not allocated to said PSS (#-32, d.c.) The method involves the steps of: &#x2014;Perform LS channel estimation on the 62 sub-carriers containing the PSS () &#x2014;reconstruct the LS channel estimation on the 64 central sub-carriers by interpolating () on subcarriers not allocated to said PSS; &#x2014;Apply () an Inverse DFT or Inverse Fast Fourrier Transform &#x2014;Extract () the L first samples, with L corresponding to the length of the channel; &#x2014;multiply () by (FF+&#x3c3;C)&#x2014;Zero-pad () the resulting signal to length 64; &#x2014;Apply () a DFT or an FFT.

Process for estimating the channel from the PSS signal in a LTE communication network, and receiver for the same

A process and receiver for canceling interference generated by a set interference base stations in a synchronized OFDM communication system and receiver in a User Equipment comprising a set of Nrx antennas. The process and receiver that cancels interference generated by a set of base stations performs OFDM demodulation on a receiver signal for each antenna of a user equipment (UE). The process and receiver also monitors each UE antenna for pilot signals generated by nearby base stations. Then the process or receiver extracts the pilot signals and establishes a list of existing base station antennas. The channel power of any interfering antennas is measured and then the Nrx-N most powerful antenna is selected. The process or receiver then performs a joint detection of the N useful Data Symbols (UDS), together with the (Nrx-N) Interfering Data Symbols (IDS) that are demodulated by demodulation blocks. Thus, after being detected, the Nrx-N most powerful IDSs can be encoded and re-injected into a cancellation loop.

Process and receiver for interference cancellation of interfering base stations in a synchronized OFDM system

A method for conditionally stopping execution of a turbo decoder is proposed. The decoder has elementary decoders. Each elementary decoder performs a sequence of decoding operations and is arranged to receive an input from at least one other elementary decoder. The method determines for each specific decoding operation if the sequence of elementary decoding operations of the specific elementary decoder has substantially converged or substantially diverged. The method terminates the execution of decoding operations if a number of sequences has substantially converged or substantially diverged.

Method and system for stopping execution of a turbo decoder

A process for computing Log-Likelihood-ratios (LLRs) in a detector of a wireless communication receiver is disclosed, with the, LLRs being used by a channel decoder. A signal is received from a telecom front end, the signal corresponding to data belonging to a finite set of constellation symbols, each constellation symbol being arranged in a lattice constellation impaired by additive noise and a multiplicative channel. A limited set of distances representative of Euclidian distances between the received signal and a finite set of predetermined constellation symbols are computed, possibly multiplied by the channel. A set of soft decision LLRs are derived from the computed set of distances under the constraint of a limited length of the list of distances. The derived LLRs are completed by clipping values read from a look-up table which is simultaneously addressed by the values of the SNR and a bit index.

Process for performing log-likelihood-ratio clipping in a soft-decision near-ML detector, and detector for doing the same

Process for equalizing a signal received in a receiver of a Terminal Equipment in a wireless communication system, said process comprises the steps of:&#x2014;receiving a signal r&#x2014;applying an iterative algorithm based on a sequence of varying preconditionners in accordance with the following formula: based on a sequence of preconditioning matrices P, each matrix depending on H, the variance of the noise, and the precedent matrices Pwithin said sequence.

Low complexity MMSE equalization process and equalizer for doing the same

To detect a cell-specific synchronization signal, a modified correlation approach is used, which removes the need for channel estimation.

Process for blind detection of a synchronization signal for LTE

A MIMO receiver for processing N data streams received by N antennas for a direct-sequence spread-spectrum wireless communication system comprising a linear equalizer operating at the chip level for performing linear chip level Inter-Chip Interference and all Inter-Stream Interference cancellation of said N data streams, and generating N output chip level data streams; de-spreading blocks for separately de-spreading the N outputs of the linear equalizer; and a non linear detector for performing spatial equalization and multi-stream detection.

Process for processing MIMO data streams in a 3GPP HSDPA receiver, and receiver for doing the same

A transmitting station (TS), for transmitting a plurality of symbols of a data signal in a communication system, comprises a process module (PM) arranged for adding subset of the symbols of the data signal to symbols of a predetermined signal prior to proceed to transmission of the data signal.

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Nice, France

Andrea Ancora