Abstract: There is provided a method of inventory control for an inventory including items sequentially arranged on one or more structures, each item having a radio frequency tag associated thereto, the tag having stored therein an identifier for identifying the associated item. The method includes: obtaining data in relation to multiple items arranged in a row on a structure, the data comprising multiple sets of identifiers detected from interrogating the tags of the plurality of items at a plurality of instances along the row; determining a sequence of detected items in the row based on the data obtained, the sequence including estimated relative positions of the detected items in the row; and determining whether an item of the detected items in the row is misplaced based on the estimated relative position of the item in the row and a reference relative position of the item in the row.

Abstract: There is provided a method of inventory control for an inventory including items sequentially arranged on one or more structures, each item having a radio frequency tag associated thereto, the tag having stored therein an identifier for identifying the associated item. The method includes: obtaining data in relation to multiple items arranged in a row on a structure, the data comprising multiple sets of identifiers detected from interrogating the tags of the plurality of items at a plurality of instances along the row; determining a sequence of detected items in the row based on the data obtained, the sequence including estimated relative positions of the detected items in the row; and determining whether an item of the detected items in the row is misplaced based on the estimated relative position of the item in the row and a reference relative position of the item in the row.

Abstract: A method of communication comprising determining whether to use distributing coding between a source (S), relay (R) and destination (D), based on a predetermined transmission rate; if the determination is positive, determining a forward error correction scheme using distributed Alamouti space-time coding, wherein the scheme is determined based on the predetermined transmission rate, a channel signal-to-noise ratio (SNR) and a network topology; relaying coded data from the S to the D using the determined forward error correction.

Abstract: A method of relaying data for a wireless frequency division multiple access network is disclosed herein. In a specific embodiment, the method comprises the steps of receiving data carried by respective subcarriers (320), network coding the data of at least two of the subcarriers having minimized correlation (350), and mapping the network coded data to a plurality of resource blocks for relaying to a destination (360). A device for relaying data for a wireless frequency division multiple access net-work is also disclosed.

Abstract: A method (500) for estimating a carrier frequency offset in a communication system (100) is disclosed herein. In a described embodiment, the communications system (100) comprises a first communications device (120), a second communications device (122) and a relay (110).

Abstract: A transmitter (106) for transmitting a signal, the signal comprising a plurality of signal values, the signal values being grouped to at least one signal value block. The transmitter comprises a pre-transformation unit (101) adapted to process each signal value block by a pre-transformation to produce a block of modulation symbols, wherein the pre-transformation comprises a phase rotation of the signal block values, which corresponds to the multiplication of the signal value block with a phase rotation matrix. The transmitter also comprises a modulation unit (102) adapted to modulate at least one carrier signal based on the modulation symbols and a sending unit (104) adapted to send the modulated carrier signal.

Abstract: A method for processing a data signal received via a communication channel is described, comprising determining a first matrix comprising components describing characteristics of the communication channel and inverting the first matrix by sub-dividing the first matrix into at least four sub matrices, inverting a first sub matrix of the four sub matrices generating a second matrix by multiplying a second sub matrix of the four sub matrices with the inverted first matrix and a third sub matrix of the four sub matrices, determining the difference matrix between the second matrix and a fourth sub matrix of the four sub matrices inverting the difference matrix and calculating the inverted matrix based on the inverted difference matrix. The data signal is processed using the inverted first matrix.

Abstract: The invention relates to a method for use in a packet-switched communication system, the method comprising: sending a first packet from a source node to a destination node, the first packet containing a first set of data bits; sending a second packet from the source node to the destination node, the second packet containing a second set of data bits; wherein, in the event that the first set of data bits cannot be successfully decoded in the destination node, the second packet further comprises a first set of error correction bits for the first set of data bits.

Abstract: A method of determining a residual frequency offset between a transmitter and a receiver in a transmission of data via a communication channel, is described, wherein the message is transmitted from the transmitter to the receiver via the communication channel and the message comprises at least one short preamble (201), at least one long preamble (202) and user data (203). The at least one long preamble (202) comprises residual frequency offset determination information based on which the residual frequency offset is determined.

Abstract: A method of communication comprising determining whether to use distributing coding between a source (S), relay (R) and destination (D), based on a predetermined transmission rate; if the determination is positive, determining a forward error correction scheme using distributed Alamouti space-time coding, wherein the scheme is determined based on the predetermined transmission rate, a channel signal-to-noise ratio (SNR) and a network topology; relaying coded data from the S to the D using the determined forward error correction.

Abstract: A method for transmitting a digital signal is described, wherein the digital signal is to be transmitted by a plurality of antennas and a 2-domain pre-transformation is carried out, i.e., in course of a pre-transformation modulation symbols assigned to subcarriers having different frequencies and assigned to subcarriers sent by different antennas are linearly combined.

Abstract: A transmitter that has a determination unit for determining a plurality of symbols (301) such that each symbol (301) has a tail component (302) and the plurality is determined in such a way that the tail components (302) are substantially equal and a tone generation unit for arranging the plurality of symbols (301) to form a plurality of long preambles (300) such that the plurality of long preambles (300) are tone-interleaved.

Abstract: A method for equalizing a digital signal received via at least one communication channel is described, wherein a block of received signal values is processed by a block-iterative equalizer (200). The equalizer comprises a feedback unit (202) and a feed-forward unit (201) each corresponding to the multiplication by a respective matrix. The matrices are updated in the iterative process.

Abstract: A method for detecting a signal received via a communication channel, the communication channel being affected by noise, is described, wherein the received signal is processed according to a filtering step (202), the filtering step comprises multiplication of at least one component of the received signal with a filter coefficient and the filter coefficient comprises a noise variance offset which corresponds to the variance of the noise.

Abstract: A method for processing a data signal received via a communication channel is described, comprising determining a first matrix comprising components describing characteristics of the communication channel and inverting the first matrix by sub-dividing the first matrix into at least four sub matrices, inverting a first sub matrix of the four sub matrices generating a second matrix by multiplying a second sub matrix of the four sub matrices with the inverted first matrix and a third sub matrix of the four sub matrices, determining the difference matrix between the second matrix and a fourth sub matrix of the four sub matrices inverting the difference matrix and calculating the inverted matrix based on the inverted difference matrix. The data signal is processed using the inverted first matrix.

Abstract: A signal reconstructing section (50), a receiver having the signal reconstructing section (50), a communication system having the receiver, and a method for reducing noise in a transformed signal having a plurality of signal components and using the signal reconstructing section (50) are described. The signal reconstructing section (50) of the receiver has a detector (52) for detecting the transformed signal, decision modules (54) each having an input (58) coupled to output (60) of the detector, and a reconstructing module (56) having inputs (62) respectively coupled to output (64) of the decision modules (54). The reconstructing module (56) is adapted to reconstruct one or more subcarriers of the plurality of subcarriers a predetermined number of times to thereby form a noise-reduced transformed signal. Reconstruction of the one or more subcarriers is performed one at a time or two or more simultaneously.

Abstract: A method for detecting a signal received via a communication channel, the communication channel being affected by noise, is described, wherein the received signal is processed according to a filtering step (202), the filtering step comprises multiplication of at least one component of the received signal with a filter coefficient and the filter coefficient comprises a noise variance offset which corresponds to the variance of the noise.

Abstract: A transmitter (106) for transmitting a signal, the signal comprising a plurality of signal values, the signal values being grouped to at least one signal value block. The transmitter comprises a pre-transformation unit (101) adapted to process each signal value block by a pre-transformation to produce a block of modulation symbols, wherein the pre-transformation comprises a phase rotation of the signal block values, which corresponds to the multiplication of the signal value block with a phase rotation matrix. The transmitter also comprises a modulation unit (102) adapted to modulate at least one carrier signal based on the modulation symbols and a sending unit (104) adapted to send the modulated carrier signal.

Abstract: The invention relates to a method for use in a packet-switched communication system, the method comprising: sending a first packet from a source node to a destination node, the first packet containing a first set of data bits; sending a second packet from the source node to the destination node, the second packet containing a second set of data bits; wherein, in the event that the first set of data bits cannot be successfully decoded in the destination node, the second packet further comprises a first set of error correction bits for the first set of data bits.

Abstract: A method for determining a frequency offset from a plurality of signal values is described wherein first correlation coefficients are determined from the signal values and second correlation coefficients are determined from the first correlation coefficients. The second correlation coefficients are linearly combined and the frequency offset is determined as the phase of the linear combination.