Abstract: A technique is provided for estimating time of arrival of a signal transmitted as a pulse and received as a sum of pulses. The received signal is filtered with a novel filter that lowers the early side lobes of the received signal to noise level. A first energy rise point is identified at a point of the main lobe of the filtered received signal, at which the energy is higher than the noise by a predetermined level. Starting from the identification of the first energy rise points, the time of arrival is estimated via curve matching, in which the shape of the filtered received signal is matched to the shape of composed by a sum of one or more reference curves that are shifted both in time and in energy. The reference curves are found by applying to the transmitted signal the same filter applied to the received signal.

Abstract: A multi-stream transmission method and device are provided for transmitting N data streams allocated to K different users. The method is implemented by a transmitter for a multi-user MIMO system having NT transmit antennas and ? k = 1 K ? ? N R k receive antennas associated with K receivers respectively associated with the K users. The method includes: performing a succession of two different iterative algorithms for calculating K precoding matrices of a linear precoder and K decoding matrices of a receiver, the receiver being of the normalized MF type with a Frobenius norm for the first algorithm, and the second iterative algorithm being initialized by a value output by the first iterative algorithm; and before each calculation of precoding matrices, calculating weights for weighting all of the streams.

Abstract: A method and apparatus for simultaneously transmitting K data streams allocated respectively to K different users. The method is implemented by a transmitter for a multi-user MIMO system having NT transmit antennas and N R = ? k = 1 K ? N R k receive antennas associated with K receivers, each associated with a respective user. The method includes, per data stream, at least: jointly calculating a linear pre-coder and a receiver adapted for a multi-user MIMO system using two different iterative algorithms in succession, wherein the second iterative algorithm is initialized with the output value from the first iterative algorithm.

Abstract: A method, system, and apparatus is provided for interference calibration. A second mobile terminal may be configured to send timing information to a network interface in an uplink channel of a second communication system. The network interface may be configured to communicate with a first mobile terminal in a downlink channel in a first communication system; estimate the uplink channel using the timing information to form a channel estimation; and adjust the downlink channel to the first mobile terminal using the channel estimation.

Abstract: A method, system, and apparatus is provided for interference calibration. A second mobile terminal may be configured to send timing information to a network interface in an uplink channel of a second communication system. The network interface may be configured to communicate with a first mobile terminal in a downlink channel in a first communication system; estimate the uplink channel using the timing information to form a channel estimation; and adjust the downlink channel to the first mobile terminal using the channel estimation.

Abstract: A multi-stream transmission method and device are provided for transmitting N data streams allocated to K different users. The method is implemented by a transmitter for a multi-user MIMO system having NT transmit antennas and ? k = 1 K ? ? N R k receive antennas associated with K receivers respectively associated with the K users. The method includes: performing a succession of two different iterative algorithms for calculating K precoding matrices of a linear precoder and K decoding matrices of a receiver, the receiver being of the normalized MF type with a Frobenius norm for the first algorithm, and the second iterative algorithm being initialized by a value output by the first iterative algorithm; and before each calculation of precoding matrices, calculating weights for weighting all of the streams.

Abstract: A method and apparatus for simultaneously transmitting K data streams allocated respectively to K different users. The method is implemented by a transmitter for a multi-user MIMO system having NT transmit antennas and N R = ? k = 1 K ? N R k receive antennas associated with K receivers, each associated with a respective user. The method includes, per data stream, at least: jointly calculating a linear pre-coder and a receiver adapted for a multi-user MIMO system using two different iterative algorithms in succession, wherein the second iterative algorithm is initialized with the output value from the first iterative algorithm.

Abstract: A process for beamforming data to be transmitted in a MU-MIMO communication system comprising a base station and a selected set of User Equipments (UE) communicating with said base station; said data being precoded by said base station in accordance with a beamforming matrix complying with a precoding matrix under the form of: (formula 1) Where—M is the number of transmit antennas—D is a diagonal unitary matrix of the form D=diag (formula 2)—P is a permutation matrix interchanging only the last M?1 rows. —A is a general Hadamard matrix. and that the signaling information transmitted by the base station to the UE comprises at least a first and a second index which are representative of D, P and A.

Abstract: The present invention, generally speaking, accelerates convergence of a fast RLS adaptation algorithm by, following processing of a burst of data, performing postprocessing to remove the effects of prewindowing, fictitious data initialization, or both. This postprocessing is part of a burst mode adaptation strategy in which data (signals) get processed in chunks (bursts). Such a burst mode processing approach is applicable whenever the continuous adaptation of the filter is not possible (algorithmic complexity too high to run in real time) or not required (optimal filter setting varies only slowly with time). Postprocessing consists of a series of “downdating” operations (as opposed to updating) that in effect advance the beginning point of the data window. The beginning point is advanced beyond fictitious data used for initialization and beyond a prewindowing region. In other variations, downdating is applied to data within a prewindowing region only.