Abstract: A technique is provided including at least obtaining a noise and interference covariance matrix, performing scaling of the noise and interference covariance matrix, determining a sum of diagonal elements of the scaled noise and interference covariance matrix, performing a first spectral shift by the sum to the scaled noise and interference covariance matrix to obtain a first spectral shifted matrix, performing eigenvalue decomposition to the first spectral shifted matrix to obtain an eigenvalue matrix, performing a second spectral shift by the sum to the eigenvalue matrix, limiting the eigenvalue matrix to a diagonal matrix, and obtaining a new noise and interference covariance matrix adding the scaled noise and interference covariance matrix and eigenvalue pairs that are obtained based, at least partly, on the performed eigenvalue decomposition.

Abstract: According to an aspect, there is provided an apparatus for performing beamforming optimization for a MIMO architecture. The apparatus maintains, in a database, channel state information of a plurality of radio channels comprising first and second order statistics. The apparatus calculates, separately for each of two or more remote radio units using an eigenbeamforming scheme, first sets of beamforming weights based on the second order statistics. Then, the apparatus performs, for each terminal device, single-user MIMO optimization between the two or more remote radio units to maximize a pre-defined metric, being a mutual information metric or signal-to-interference-plus-noise, based on first sets of beamforming weights and the first order statistics. The result, for each terminal device, is a second set of beamforming weights. The apparatus causes transmitting data using beams formed by applying both first and second sets of optimized beamforming weights at the two or more remote radio units.

Abstract: A method comprising obtaining a noise and interference covariance matrix, performing scaling of the noise and interference covariance matrix, determining a sum of diagonal elements of the scaled noise and interference covariance matrix, performing a first spectral shift by the sum to the scaled noise and interference covariance matrix to obtain a first spectral shifted matrix, performing eigenvalue decomposition to the first spectral shifted matrix to obtain an eigenvalue matrix, performing a second spectral shift by the sum to the eigenvalue matrix, limiting the eigenvalue matrix to a diagonal matrix, and obtaining a new noise and interference covariance matrix adding the scaled noise and interference covariance matrix and eigenvalue pairs that are obtained based, at least partly, on the performed eigenvalue decomposition.

Abstract: According to an aspect, there is provided an apparatus for performing beamforming optimization for a MIMO architecture. The apparatus maintains, in a database, channel state information of a plurality of radio channels comprising first and second order statistics. The apparatus calculates, separately for each of two or more remote radio units using an eigenbeamforming scheme, first sets of beamforming weights based on the second order statistics. Then, the apparatus performs, for each terminal device, single-user MIMO optimization between the two or more remote radio units to maximize a pre-defined metric, being a mutual information metric or signal-to-interference-plus-noise, based on first sets of beamforming weights and the first order statistics. The result, for each terminal device, is a second set of beamforming weights. The apparatus causes transmitting data using beams formed by applying both first and second sets of optimized beamforming weights at the two or more remote radio units.

Abstract: A method and apparatus is disclosed for determining a signal subspace in a communications system. A remote apparatus obtains signal streams from antenna elements or signal streams from antenna beams. Based on the obtained signal streams, the apparatus selects a signal subspace for a user, the signal sub-space having a dimension M. Based on the selected signal subspace, the apparatus transmits, via an interface to a central apparatus, M streams of post-fast-Fourier-transform data, the interface being capable of transmitting a different sub-space for different frequency bins.

Abstract: A method and corresponding equipment for use by a mobile station and/or a radio access network, for altering one or more characteristics of transmissions of the mobile station to a base transceiver station of the radio access network in respect to power and/or modulation and/or coding of the transmissions, based on monitoring broadcast transmissions from other base transceiver stations of the radio access network and determining an estimate of the likelihood of transmissions by the mobile station interfering with communication between the other base transceiver stations and the mobile stations in communication with those other base transceiver stations.

Abstract: Methods, apparatuses, controllers, systems, and terminals can, in certain embodiments, determine a number and properties of potential interferers in a plurality of available radio channels. The properties of the potential interferers can include modulation methods used by the potential interferers. A network element responsible for channel allocation can perform channel allocation for a terminal and select a modulation method for the allocated channel on the basis of the determination.

Abstract: Methods, apparatuses, controllers, systems, and terminals can, in certain embodiments, determine a number and properties of potential interferers in a plurality of available radio channels. The properties of the potential interferers can include modulation methods used by the potential interferers. A network element responsible for channel allocation can perform channel allocation for a terminal and select a modulation method for the allocated channel on the basis of the determination.

Abstract: A network element, a terminal and a method of allocating a radio channel to a connection between a terminal and a base station in a telecommunication system are provided. The number and properties of potential interferers in a plurality of available radio channels are determined, and channel allocation is performed on the basis of the determination.

Abstract: A frequency error correction scheme applicable in a receiver of a mobile telecommunication system is presented. The present frequency error correction scheme is carried out in a time domain after an equalization process. The present frequency error correction scheme may be applied to a base station receiving signals transmitted according to a single-carrier frequency division multiple access communication scheme. The separation of different received signals for further processing is carried out in the frequency domain before the equalization and the frequency error correction.

Abstract: An apparatus includes a radio frequency receiver and a timing adjustment unit that contains at least two channel impulse response estimators. The at least two channel impulse response estimators include an on-time estimator and at least one of an early estimator and a late estimator. The apparatus also includes a calculation unit that is configurable to obtain a channel estimate for each measured channel impulse response and to average obtained channel estimates over a plurality of received signal events to determine a timing adjustment in accordance with residual signal power.

Abstract: There is provided a method of clipping a transmission signal. The method comprises: providing a residual signal of a complex envelope clipper based on the transmission signal to be clipped; providing a reference signal respective to the residual signal, the reference signal corresponding to an ideal residual signal; forming a clipping signal on the basis of the residual signal and the reference signal; subtracting the clipping signal from the residual signal for removing higher amplitudes of the residual signal; and subtracting the clipping signal from the reference signal for providing a reference signal respective to the clipped residual signal.

Abstract: A method of reducing the peak-to-mean ratio of a multi-carrier signal includes the steps of: generating a residual signal from the multicarrier signal, the residual signal representing the difference between the multicarrier signal and a hard-clipped multicarrier signal. The method also includes the steps of applying a least squares function to the residual signal for each carrier of the multi-carrier signal, thereby generating a minimized residual signal for each carrier and combining the minimized residual signals and the multicarrier signal.

Abstract: A method, mobile device, network device, system, and software are devised for soft value scaling with a single antenna interference cancellation (SAIC) receiver, or with an interference rejection combining (IRC) receiver, in an unsynchronized network. A signal is received having interference that is caused by a non-synchronized network. A desired power level of that signal is calculated. Then the desired power is compared to a total power of the signal, in order to identify a portion of a received burst having substantial interference. Then that portion of the received burst is weighted, to reduce its importance during decoding.

Abstract: The specification and drawings present a new method, system, apparatus and software product for using a new modified dual symbol rate (MDSR) in an uplink direction in mobile communication systems. The communication between the mobile station and the network element may be performed within evolved GSM/EDGE radio access networks. The MDSR can be for example one and a half times a symbol rate of an uplink speech service, e.g., the current GSM/EDGE symbol rate (13/48 MHz) in the mobile communication system, thus the MDSR may be substantially 13/32 MHz or about 405 kHz. The uplink signal with the MDSR may be modulated, e.g., using a quadrature amplitude modulation (QAM), e.g., 16-QAM with 16 states and/or a quadrature phase-shift keying (QPSK, or ?/4-QPSK) modulation.

Abstract: An indicator of a strength of a signal comprising a training sequence portion received in a radio propagation environment is provided. Samples are taken from the training sequence portion, an energy value of the samples over an estimated channel impulse response is computed and the indicator of the strength of the signal is estimated from the energy value.

Abstract: Embodiments of the invention relate to uplink communication in a GSM/EDGE telecommunication system. A method according to certain embodiments of the invention include at least one wide-band carrier wave in the group of carrier waves being generated in a mobile station by applying linear modulation at a first modulation symbol rate, the first modulation symbol rate being a multiple of a second modulation symbol rate, while preserving a predefined carrier spacing and allowing the at least one wide-band carrier wave to overlap with at least one adjacent carrier wave.

Abstract: The invention relates to a method of estimating a noise and interference covariance matrix and to a receiver. The method comprises: estimating an initial noise and interference covariance matrix on the basis of a received signal; reducing the impact of the background noise of the receiver from the initial noise and interference covariance matrix for obtaining a residual matrix; accepting the obtained residual matrix when the residual matrix is at least approximately positive semidefinite; modifying the obtained residual matrix such that the positive semidefinity of the residual matrix is achieved when the residual matrix is not at least approximately positive semidefinite; and adding the impact of background noise back to the residual matrix for estimating a final noise and interference covariance matrix.

Abstract: A transmitter clips a transmission signal before transmission in order to reduce the strength of at least one peak of the transmission signal exceeding a predetermined threshold. The transmitter includes a clipper having a minimizer, a filter and an adder. The minimizer minimizes of a cost function with respect to an optimization signal, the cost function having weighted terms as a function of the optimization signal. The terms relate to an effective modulation distortion and an effective overshoot exceeding the predetermined threshold. The filter forms a clipping signal by filtering the optimization signal formed as a result of the minimization according to the spectrum emission mask requirements of the radio system. The adder subtracts the clipping signal from the transmission signal.

Abstract: An apparatus includes a radio frequency receiver and a timing adjustment unit that contains at least two channel impulse response estimators. The at least two channel impulse response estimators include an on-time estimator and at least one of an early estimator and a late estimator. The apparatus also includes a calculation unit that is configurable to obtain a channel estimate for each measured channel impulse response and to average obtained channel estimates over a plurality of received signal events to determine a timing adjustment in accordance with residual signal power.