Abstract: A method and apparatus are provided for generating and transmitting a multicarrier signal representing data symbols, where the multicarrier signal is a linear combination of subcarriers. The apparatus modulates base signals with the data symbols, where each one of the base signals is a weighted sum of the subcarriers, whereby each one of the subcarriers is weighted by an element of a weighting vector residing in a nullspace of a constraint matrix. The constraint matrix represents constraints limiting a magnitude of the multicarrier signal's Fourier transform at frequencies outside a designated bandwidth.

Abstract: A method is provided for generating and allocating time-frequency mapping pattern (TFP) in a communication system. A set of orthogonal TFPs is generated from a TFP. And a TFP from the set of orthogonal TFPs is allocated to a user equipment in a transmission time interval, TTI, within a cell of the communication system. Also provided are a transmitter, a base station, and a user equipment.

Abstract: A method for generating and transmitting a multicarrier signal representing data symbols, where the multicarrier signal is a linear combination of subcarriers, is disclosed, as well as a transmission entity. The generation and transmission is characterized by modulation of base signals with the data symbols, wherein each one of the base signals is a weighted sum of the subcarriers, whereby each one of the subcarriers is weighted by an element of a weighting vector residing in a nullspace of a constraint matrix, wherein the constraint matrix represents constraints limiting a magnitude of the multicarrier signal's Fourier transform at frequencies outside a designated bandwidth.

Abstract: A method and apparatus for multiplexing communication resources to multiple users in a communication system is provided. A generic time-frequency (T-F) mapping pattern (TFPgeneric) and a set of orthogonal T-F mapping patterns (TFPs) comprising TFPgeneric is generated. In each transmission time interval (TTI), the set of TFPs is cyclically offset by a random variable and the offset TFPs are allocated to one or more users and/or traffic channels.

Abstract: Methods for transmission and detection, as well as a transmitter and a receiver for performing the methods are disclosed. An example transmission method according to an aspect of the invention includes determining of a modulation vector for an information symbol vector and modulating subcarriers with elements of the modulation vector. Example resulting out-of-band signal power emission improvements over prior art are demonstrated.

Abstract: Carrier aggregation in a radio communication system is disclosed, in which at least two Orthogonal Frequency Division Multiplexing (OFDM) carriers are aggregated, each of the at least two OFDM carriers comprising subcarriers being spaced in accordance with a subcarrier spacing of the radio communication system, transmission on the at least two OFDM carriers being synchronized in time.

Abstract: OFDM signal transmission of reduced power emission outside a designated transmission bandwidth is disclosed. At least one subcarrier is allocated for an OFDM symbol for non-data. A weighting signal representation is determined based on an initial error signal representation, which is determined from at least part of a first OFDM symbol and part of a second OFDM symbol, the first and second OFDM symbols being consecutive in time.

Abstract: An improved method for reducing an amount of precoding feedback information in a multi-carrier Multiple-Input Multiple-Output (MIMO) communication system using precoding is disclosed. At the receiving end, the method jointly selects, while considering transmission quality for each relevant combination of sub-bands and matrices, a limited number of P codebook indices and a limited number of K? sub-bands to be included in a subset ? (m1, . . . , mK?) of a set ? of allowed sub-bands. K? is here set to a value K?<K and P is set to a value P?K?. The P codebook indices and information identifying the subset ? is then conveyed to the transmitting end.

Abstract: An method for, in a cellular telecommunication system, generating reference sequence matrices and for mapping elements of said reference sequence matrices to reference signal positions having predetermined locations in two-dimensional multi-carrier time-frequency symbol spaces is provided. According to the method, a matrix SN of dimension N×N having N orthogonal rows or columns and orthogonal parts of rows or columns, respectively, N being a positive integer >3, is generated. N reference sequence matrices OS(k), k=0, . . . , N?1, are then generated by forming rows or columns of the kth reference sequence matrix OS(k) based on at least part of the (k+1)th row or column, respectively, of said orthogonal matrix SN. Further, in a cell, within a given time period, mapping elements of one of said N reference sequence matrices OS(k) to reference signal positions having predetermined locations in two-dimensional multi-carrier time-frequency symbol spaces.

Abstract: An improved method for reducing an amount of precoding feedback information in a multi-carrier Multiple-Input Multiple-Output (MIMO) communication system using precoding is disclosed. At the receiving end, the method jointly selects, while considering transmission quality for each relevant combination of sub-bands and matrices, a limited number of P codebook indices and a limited number of K? sub-bands to be included in a subset ? (m1, . . . , mK?) of a set ? of allowed sub-bands. K? is here set to a value K?<K and P is set to a value P?K?. The P codebook indices and information identifying the subset ? is then conveyed to the transmitting end.

Abstract: The present invention relates to a method for channel quality estimation in a wireless data communication system, wherein data streams are transmitted from a transmitter having multiple antennas and/or antenna elements to a receiver over a frequency band, wherein, during a first period of time, data streams are transmitted on at least one sub-band of the frequency band using a first beamforming constellation, and wherein, during a subsequent second period of time, data streams are transmitted on said sub-band using a second beamforming constellation. The method further includes a training step, during the first period of time, wherein a data stream is transmitted on a portion of, or adjacent to, said sub-band while using the beamforming constellation to be used in said second period of time. The present invention also relates to a system, a transmitter and a communication system.

Abstract: The present invention relates to a method for allocating communication resources in a multi-user cellular communication system, wherein communication resources are divided in time periods and frequency sub-bands, wherein part of the communication resources are used for frequency-localized communication channels, and part of the communication resources are used for frequency distributed channels. The method further comprises the steps of classifying part of the frequency sub-bands as frequency sub-bands carrying frequency-distributed channels, classifying the remaining part of the frequency sub-bands as frequency sub-bands carrying frequency-localized channels. The present invention also relates to a system, a transmitter and a communication system.

Abstract: A transmitter in which modulator output signal values are generated by a multi-level modulation method. The transmitter comprises a look-up table for storing a pre-defined number of values corresponding to data symbols and representing a signal or a pulse format, registers for selecting values representing the signal or the pulse format to be used to defined in-phase and quadrature component values, and adders for defining the modulator output signal values by summing the in-phase and quadrature component values while the number of the in-phase and quadrature component values to be summed is determined by a number of inter-dependent symbols.

Abstract: The invention is related to a transmitter in which modulator output signal values are generated by a multi-level modulation method. The transmitter comprises means (606) for storing a pre-defined number of values corresponding to data symbols and representing a signal or a pulse format, the transmitter comprises means (602, 604) for selecting values representing a signal or a pulse format to be used to define in-phase and quadrature values, the transmitter comprises means (602, 604, 606) for defining in-phase and quadrature component values using the selected values corresponding to data symbols and representing a signal or a pulse format, the transmitter comprises means (608, 610) for defining modulator output signal values by summing in-phase and quadrature component values while the number of in-phase and quadrature component values to be summed is determined by the number of inter-dependent symbols.

Abstract: A method and equipment for providing frequency synchronization in a telecommunications system, wherein time stamps providing timing information are transferred over a packet-switched network from a transmitter network element to a receiver network element having a receiver oscillator. The expected times for reception of time stamps are estimated (i), deviations from the estimated expected time for the time stamps are calculated (ii) and at least one time stamp deviating most from the estimated expected time is removed (iii). The steps (i)-(iii) are repeated until a pre-determined number of time stamps is removed. Frequency of the receiver oscillator is then estimated using the remaining time stamps and the frequency generation of the receiver oscillator is adjusted based on the estimated frequency.

Abstract: A radio signal transmitted from a transmitter to a receiver of a mobile communications system, such as the GSM system, often suffers from a phenomenon known as frequency offset by which the frequency of the radio signal is changed from a first frequency to a second frequency. A method is therefore provided for automatically correcting the frequency at the receiver to restore the received radio signal to approximately the first frequency using a multistage frequency correction algorithm. The radio signal comprises a training sequence that is known to the receiver and data symbols that are not known to the receiver. In the first stage of the frequency correction, the frequency offset is coarsely estimated based on the training sequence only, and the data symbols are frequency corrected by back-rotating the received data symbols and the training sequence by the frequency offset estimate.

Abstract: A method and equipment for providing frequency synchronization in a telecommunications system, wherein time stamps providing timing information are transferred over a packet-switched network from a transmitter network element to a receiver network element having a receiver oscillator. The expected times for reception of time stamps are estimated (i), deviations from the estimated expected time for the time stamps are calculated (ii) and at least one time stamp deviating most from the estimated expected time is removed (iii). The steps (i)-(iii) are repeated until a pre-determined number of time stamps is removed. Frequency of the receiver oscillator is then estimated using the remaining time stamps and the frequency generation of the receiver oscillator is adjusted based on the estimated frequency.