Abstract: An embodiment of the time-variant channel estimation in an OFDM transmission system envisages the operations of: a) determining the received signal vector Yj,k for one or more of R receiving antennas, j=1, . . .

Abstract: Embodiments of a method and an apparatus for detecting multiple complex-valued symbols belonging to discrete constellations. The method and apparatus is a detector that finds a closest vector, or a close approximation of it, to a received vector. The disclosure also gets (optimally, in case of two transmit sources) or closely approximates (for more than two transmit sources) the most likely sequences required for an optimal bit or symbol a-posteriori probability computation. Also part of the present disclosure is represented by Also embodiments of a method and an apparatus to determine a near-optimal ordering algorithms for the aforementioned purpose. The method and apparatus achieves optimal performance for two transmit antennas and achieves near-optimal performance for a higher number of antennas, with a lower complexity as compared to a maximum-likelihood detection method and apparatus. The method and apparatus are suitable for highly parallel hardware architectures.

Abstract: An embodiment of the time-variant channel estimation in an OFDM transmission system envisages the operations of: a) determining the received signal vector Yj,k for one or more of R receiving antennas, j=1, . . .

Abstract: An embodiment of the time-variant channel estimation in an OFDM transmission system envisages the operations of: a) determining the received signal vector Yj,k for one or more of R receiving antennas, j=1, . . .

Abstract: An embodiment of an arrangement detects sequences of digitally modulated symbols from multiple sources. The arrangement identifies a suitable set of candidate values for at least one transmitted sequence of symbols and determines for each candidate value a set of sequences of transmitted symbols. The arrangement estimates at least one further set of sequences of transmitted symbols, calculates a metric for each sequence of transmitted symbols, and selects the sequence that maximizes the metric. At the end, a-posteriori bit soft output information for the selected sequence is calculated from the metrics for said sequences. Generally, these calculations are based on the information coming from a channel-state-information matrix and a-priori information on the modulated symbols from a second module, such as a forward error-correction-code (ECC) decoder.

Abstract: A method, apparatus, and computer program for detecting sequences of digitally modulated symbols transmitted by multiple sources are provided. A real-domain representation that separately treats in-phase and quadrature components of a received vector, channel gains, and a transmitted vector transmitted by the multiple sources is determined. The real-domain representation is processed to obtain a triangular matrix. In addition, at least one of the following is performed: (i) hard decision detection of a transmitted sequence and demapping of corresponding bits based on a reduced complexity search of a number of transmit sequences, and (ii) generation of bit soft-output values based on the reduced complexity search of the number of transmit sequences. The reduced complexity search is based on the triangular matrix.

Abstract: An embodiment of a method and device for detecting a signal and generating bit soft-output of a multiple-input multiple-output system is provided. The device includes at least one channel estimates pre-processing unit, one received vector processing and one detection and soft-output generation unit. The pre-processing unit calculates multiple QR Decompositions of the input channel estimation matrix. The detection and soft-output generation unit computes near optimal bit soft output information with a deterministic complexity and latency. It may implement a reduced complexity search method. Globally, embodiments of the invention may allow achieving low complexity, high data rate, scalability in terms of the dimension of the MIMO system and flexibility versus the supported modulation order, all potentially key factors for most MIMO wireless transmission applications.

Abstract: An embodiment of an arrangement detects sequences of digitally modulated symbols from multiple sources. The arrangement identifies a suitable set of candidate values for at least one transmitted sequence of symbols and determines for each candidate value a set of sequences of transmitted symbols. The arrangement estimates at least one further set of sequences of transmitted symbols, calculates a metric for each sequence of transmitted symbols, and selects the sequence that maximizes the metric. At the end, a-posteriori bit soft output information for the selected sequence is calculated from the metrics for said sequences. Generally, these calculations are based on the information coming from a channel-state-information matrix and a-priori information on the modulated symbols from a second module, such as a forward error-correction-code (ECC) decoder.

Abstract: One or more embodiments to iteratively detect and decode data transmitted in a wireless communication system, featuring a MIMO detector and a soft input soft-output error-correction-code decoder. More specifically, a method suitable for iterative detection and decoding schemes is proposed, which is able to output near optimal bit soft information processing efficiently given input bit soft information. First, a transmitting source is selected as a reference layer, wherein the associated symbol represents a reference transmit symbol. Subsequently, a set of candidate values are identified for the reference transmit symbol. For each candidate value a candidate transmit sequence is estimated through a novel spatial decision feedback equalization process based on both Euclidean distance metrics and the a-priori soft information provided by the SISO ECC decoder. The novel DFE technique uses a novel bit metric.

Abstract: A method (200a-200b), apparatus (104), and computer program for detecting sequences of digitally modulated symbols transmitted by multiple sources (102, 102a-102t) are provided. A real-domain representation that separately treats in-phase and quadrature components of a received vector, channel gains, and a transmitted vector transmitted by the multiple sources (102, 102a-102t) is determined. The real-domain representation is processed to obtain a triangular matrix. In addition, at least one of the following is performed: (i) hard decision detection of a transmitted sequence and demapping of corresponding bits based on a reduced complexity search of a number of transmit sequences, and (ii) generation of bit soft-output values based on the reduced complexity search of the number of transmit sequences. The reduced complexity search is based on the triangular matrix.

Abstract: An embodiment of an arrangement for detecting sequences of digitally modulated symbols from multiple sources. The arrangement identifies a suitable set of candidate values for at least one transmitted sequence of symbols and determines for each candidate value a set of sequences of transmitted symbols. The arrangement estimates at least one further set of sequence of transmitted symbols, calculates a metric for each sequence of transmitted symbols and selects the sequence that maximizes the metric. At the end, a-posteriori bit soft output information for the selected sequence is calculated from the metrics for said sequences. Generally, these calculations are base on the information coming from a channel state information matrix and a-priori information on said modulated symbols from a second module, such as a forward error correction code decoder.

Abstract: An embodiment of the time-variant channel estimation in an OFDM transmission system envisages the operations of: a) determining the received signal vector Yj,k for one or more of R receiving antennas, j=1, . . .

Abstract: An embodiment of a method and device for detecting a signal and generating bit soft-output of a multiple-input multiple-output system is provided. The device includes at least one channel estimates pre-processing unit, one received vector processing and one detection and soft-output generation unit. The pre-processing unit calculates multiple QR Decompositions of the input channel estimation matrix. The detection and soft-output generation unit computes near optimal bit soft output information with a deterministic complexity and latency. It may implement a reduced complexity search method. Globally, embodiments of the invention may allow achieving low complexity, high data rate, scalability in terms of the dimension of the MIMO system and flexibility versus the supported modulation order, all potentially key factors for most MIMO wireless transmission applications.

Abstract: Low density parity check (LDPC) codes (LDPCCs) have an identical code blocklength and different code rates. At least one of the rows of a higher-rate LDPC matrix is obtained by combining a plurality of rows of a lower-rate LDPC matrix with the identical code blocklength as the higher-rate LDPC matrix.

Abstract: One or more embodiments to iteratively detect and decode data transmitted in a wireless communication system, featuring a MIMO detector and a soft input soft-output error-correction-code decoder. More specifically, a method suitable for iterative detection and decoding schemes is proposed, which is able to output near optimal bit soft information processing efficiently given input bit soft information. First, a transmitting source is selected as a reference layer, wherein the associated symbol represents a reference transmit symbol. Subsequently, a set of candidate values are identified for the reference transmit symbol. For each candidate value a candidate transmit sequence is estimated through a novel spatial decision feedback equalization process based on both Euclidean distance metrics and the a-priori soft information provided by the SISO ECC decoder. The novel DFE technique uses a novel bit metric.

Abstract: Embodiments of a method and an apparatus for detecting multiple complex-valued symbols belonging to discrete constellations. The method and apparatus is a detector that finds a closest vector, or a close approximation of it, to a received vector. The invention also gets (optimally, in case of two transmit sources) or closely approximates (for more than two transmit sources) the most likely sequences required for an optimal bit or symbol a-posteriori probability computation. Also part of the present invention is represented by Also embodiments of a method and an apparatus to determine a near-optimal ordering algorithms for the aforementioned purpose. The method and apparatus achieves optimal performance for two transmit antennas and achieves near-optimal performance for a higher number of antennas, with a lower complexity as compared to a maximum-likelihood detection method and apparatus. The method and apparatus are suitable for highly parallel hardware architectures.

Abstract: A method (200a-200b), apparatus (104), and computer program for detecting sequences of digitally modulated symbols transmitted by multiple sources (102, 102a-102t) are provided. A real-domain representation that separately treats in-phase and quadrature components of a received vector, channel gains, and a transmitted vector transmitted by the multiple sources (102, 102a-102t) is determined. The real-domain representation is processed to obtain a triangular matrix. In addition, at least one of the following is performed: (i) hard decision detection of a transmitted sequence and demapping of corresponding bits based on a reduced complexity search of a number of transmit sequences, and (ii) generation of bit soft-output values based on the reduced complexity search of the number of transmit sequences. The reduced complexity search is based on the triangular matrix.

Abstract: An embodiment of an arrangement for detecting sequences of digitally modulated symbols from multiple sources. The arrangement identifies a suitable set of candidate values for at least one transmitted sequence of symbols and determines for each candidate value a set of sequences of transmitted symbols. The arrangement estimates at least one further set of sequence of transmitted symbols, calculates a metric for each sequence of transmitted symbols and selects the sequence that maximizes the metric. At the end, a-posteriori bit soft output information for the selected sequence is calculated from the metrics for said sequences. Generally, these calculations are base on the information coming from a channel state information matrix and a-priori information on said modulated symbols from a second module, such as a forward error correction code decoder.

Abstract: A method for designing a new prunable S-random interleaver class to be used as a constituent part of turbo codes. With respect to previously proposed solutions the method has the advantage of being prunable to different block sizes while exhibiting at the same time, for any considered block size, performance comparable with the optimized “ad hoc” S-random interleavers. Another advantage is that, as for every S-random interleaver, the design rules are independent of the constituent codes and of the puncturing rate applied to the turbo code. Therefore, these interleavers potentially can find applications in any turbo code scheme that requires interleaver size flexibility and code rate versatility, thanks to the advantage of requiring a single law storage (i e., one ROM storage instead of several ROMs) from which all the others are obtained by pruning, without compromising the overall error rate performance.

Abstract: Low density parity check (LDPC) codes (LDPCCs) have an identical code blocklength and different code rates. At least one of the rows of a higher-rate LDPC matrix is obtained by combining a plurality of rows of a lower-rate LDPC matrix with the identical code blocklength as the higher-rate LDPC matrix.