56 results about "Mimo detector" patented technology

A method and system for detecting and decoding multiple signals. A low-complexity MIMO detector that combines sphere decoding and m-algorithm approaches, while accounting for the effect of channel condition on the decoding operation, is provided. Taking into account the channel condition effectively controls the size of the search tree, and consequently the search complexity, in an adaptive manner. The channel condition is exploited in the construction of the tree to manage the number of branches in the tree and to avoid undesirable growth.

A method and system is provided that selects transmission modes between spatial multiplexing, delay diversity and space-time coding in 802.11n systems. As such, eigen-value computation for mode selection is not required. This provides efficiency, in particular for basic receiver structure where a linear MMSE or ZF MIMO detector is applied. Further, mode selection using a simple metric provides accurate mode selection. In addition by switching between different transmission modes, a link adaptation algorithm according to the present invention provides improved system performance.

A MIMO detection method for a receiver in a MIMO system using N-QAM for modulation, the MIMO detection method including generating a plurality of symbol vector sets and a plurality of search radiuses, selecting a candidate symbol vector set corresponding to a highest level of a multilevel structure of N-QAM constellation, generating a search space corresponding to a lower level of the multilevel structure of N-QAM constellation according to the selected candidate symbol vector set, confirming which level the search space corresponds to, and generating a detection signal according to the search space when the level of the search space is the lowest level of the multilevel structure of the N-QAM constellation.

An Iterative Detection and Decoding (IDD) receiving apparatus and method in a multiple input multiple output (MIMO) communication system. The IDD receiving apparatus includes an MIMO detector which generates soft decision values of coded bits by MIMO-decoding a receive vector, feedback priori information, and a list of candidate coded symbol vectors; a decoder which Soft-Input / Soft-Output (SISO)-decodes the soft decision values generated at the MIMO detector and feeds back soft decision values of the coded bits to the MIMO detector; a hard decision part which generates a coded symbol vector by performing a hard decision on the soft decision values generated at the decoder; and a list updater which generates a list of candidate coded symbol vectors using the receive vector and provides the list to the MIMO detector at a first iteration, updates the list using the coded symbol vector fed from the hard decision part, and provides the updated list to the MIMO detector at subsequent iterations.

A method and system for detecting and decoding multiple signals. A low-complexity MIMO detector that combines sphere decoding and m-algorithm approaches, while accounting for the effect of channel condition on the decoding operation, is provided. Taking into account the channel condition effectively controls the size of the search tree, and consequently the search complexity, in an adaptive manner. The channel condition is exploited in the construction of the tree to manage the number of branches in the tree and to avoid undesirable growth.

The performance of multiple-input multiple-output (MIMO) systems, employing coding with multiple antennas depends heavily on the demapper algorithm which is used for MIMO detection. Soft-output demappers lead to better bit error rate (BER) performance compared to hard-decision demappers, but have a higher implementation complexity. The algorithm, proposed in this paper, relies on low-complexity harddecision MIMO detection. The reliability information for the received bits used to compute log-likelihood ratios is based on an estimate of the average bit error rate which is for example derived from the corresponding channel state information only. The algorithm is applicable to any hard-decision MIMO detector. As an example, we describe the application of the scheme to a linear MMSE detector and to sphere decoding with early termination.

A MIMO detection method for a receiver in a MIMO system using N-QAM for modulation, the MIMO detection method including generating a plurality of symbol vector sets and a plurality of search radiuses, selecting a candidate symbol vector set corresponding to a highest level of a multilevel structure of N-QAM constellation, generating a search space corresponding to a lower level of the multilevel structure of N-QAM constellation according to the selected candidate symbol vector set, confirming which level the search space corresponds to, and generating a detection signal according to the search space when the level of the search space is the lowest level of the multilevel structure of the N-QAM constellation.

A scalable Multiple-Input Multiple-Output (MIMO) detector, comprises an ordering block, a group interference suppression block, a core detector and a residual detector. The ordering block determines an order of the columns of a channel matrix including received streams based on the power thereof. The group interference suppression block coupled to the ordering block groups received streams into a core part and a residual part, the core part including a first received stream and a second received stream corresponding to the first two columns of the channel matrix in the order, the first received stream and the second received stream forming a received signal vector, and the residual part including the rest of the received streams. The core detector detects the core part based on a 2×2 Simplified Maximum Likelihood (SML) detection. The residual detector detects the residual part by Vertical Bell Laboratories Layered Space Time (VBLAST) detection.

This invention is related to a low-complexity MIMO detector in a wireless communication system with near optimal performance. An initial symbol estimation is performed for a received symbol vector. The soft information of the received symbol vector can be more accurately calculated using every candidate symbol vector of a combined set of candidate symbol vectors, wherein the combined set is generated based on the initial estimation. By combining aspects of both the linear detection and the ML detection, the complexity of the proposed detector becomes orders of magnitude lower than that of a ML detector, but the performance is very close to that of an ML detector.

A Lenstra-Lenstra-Lovász (LLL)-based technique is utilized to reduce the complexity of a MIMO detector. Basis vectors can be pre-sorted, such as by V-BLAST ordering or sorted-QR ordering, prior to applying Gram-Schmidt Orthogonalization (GSO) to further improve performance. Alternatively, a joint sorting and LLL reduction (JSAR) technique can be utilized such that after each reduction step, a vector remaining to be reduced can be selected that will minimize the overall complexity. The JSAR technique can be applied on real or complex lattice bases. LLL reduction can be stopped after a predetermined threshold is exceeded.

A hybrid soft output MIMO detector uses a QR decomposition detector followed by a Markov chain Monte Carlo detector. The QRD-M generates initial candidate decision vectors, which are used as input for the Markov chain Monte Carlo detection to generate the soft output.

The present invention relates to the fields of precoded spatial multiplexing MIMO communication systems, especially to the subject of selecting precoding matrices. The present invention especially relates to a communication device, a communication method and a software program product. The MIMO communication device according to the present invention comprises a memory for storing a plurality of MIMO precoding matrices realizing the transmission side encoding of an Eigenbeamforming system; a controller for calculating, for each of at least some of the stored precoding matrices, an indicator value of the SNR of at least one decoupled transmission channel based on at least part of the corresponding precoding matrix, and for selecting one of said stored precoding matrices based on said calculated at least one indicator value of the SNR; and a MIMO detector for detecting symbols based on said selected precoding matrix. Because selection of the precoding matrices is based on SNR indicator values, the SNR can be optimized which is resulting in a higher data rate. Moreover, no computationally complex calculation of a SVD is required for the precoding matrix selection according to the present invention.

A method and a communication receiver have been described for calculating log-likelihood ratios in a communication receiver. The log-likelihood ratio is calculated for each bit of one or more subsymbols of each of the one or more spatial streams by computing effective noise on one or more spatial streams after considering noise terms resulting from MIMO detection estimates of the subsymbols on each spatial stream. Finally, signal to noise ratio is determined for one or more spatial streams from the effective noise and scaling bit log-likelihood ratios with the signal to noise ratio.

A hybrid soft output MIMO detector uses a QR decomposition detector followed by a Markov chain Monte Carlo detector. The QRD-M generates initial candidate decision vectors, which are used as input for the Markov chain Monte Carlo detection to generate the soft output.

The invention discloses a distributed detection method of a large-scale multiuser MIMO system. The method comprises the following steps: dividing received signals into multiple groups, performing distributed signal detection on each group of received signals by using an MIMO signal detection module based on an EP algorithm, and then adopting different processing processes on three EP MIMO detectors to obtain a final detection result. According to the distributed detection method disclosed by the invention, the application complexity of the EP algorithm in the signal detection of the large-scale multiuser MIMO system is greatly reduced by a distributed design, the three distributed MIMO detectors based on the EP algorithm have excellent performance in the large-scale multiuser MIMO system,and the distributed detection method can be implemented in terms of complexity.

A high throughput and scalable MIMO detector can use a K-Best detection algorithm to find K combinations of transmit symbols that are likely to be the symbols that were actually transmitted. The K-best MIMO detector can include a plurality of stages, where each stage may correspond to a transmit antenna, and each stage can find K best symbol combinations based on information from a previous stage. To find the new K best symbol combinations, at each stage, a plurality of metrics for potential combinations are computed and sorted by magnitude. The MIMO detector preferably uses a high throughput, merge sorting algorithm to sort the metrics.

In a MIMO detector, a slicing list detection scheme employs a complex plane to represent symbols in an alphabet, in which all decision regions are bounded by either vertical lines or horizontal lines. A K-best scheme accesses the complex plane and an offline-generated lookup table to detect elements of a received vector. At each level, the system prunes all but the K-best candidates from each surviving node through the slicing list detector.

A method and a communication receiver have been described for calculating log-likelihood ratios in a communication receiver. The log-likelihood ratio is calculated for each bit of one or more subsymbols of each of the one or more spatial streams by computing effective noise on one or more spatial streams after considering noise terms resulting from MIMO detection estimates of the subsymbols on each spatial stream. Finally, signal to noise ratio is determined for one or more spatial streams from the effective noise and scaling bit log-likelihood ratios with the signal to noise ratio.

A receiver and a receiving method for a Single Carrier Frequency Division Multiple Access (SC-FDMA) system are provided. The receiver includes a matrix selector for selecting a constant channel matrix according to a Multiple-Input Multiple-Output (MIMO) reception scheme, a channel equalizer for equalizing a multi-path channel to a specific path channel in a frequency domain by using the constant channel matrix, and a MIMO detector for detecting a Euclidean distance of transmittable symbols from a time-domain Transmit (Tx) signal by using the channel equalized in the frequency domain and then for selecting a symbol having a minimum distance.

This invention is related to a low-complexity MIMO detector in a wireless communication system with near optimal performance. An initial symbol estimation is performed for a received symbol vector. The soft information of the received symbol vector can be more accurately calculated using every candidate symbol vector of a combined set of candidate symbol vectors, wherein the combined set is generated based on the initial estimation. By combining aspects of both the linear detection and the ML detection, the complexity of the proposed detector becomes orders of magnitude lower than that of a ML detector, but the performance is very close to that of an ML detector.

A MIMO detector for use in MIMO-OFDM wireless communication that forms a plurality of propagation paths by using a plurality of transmitting and receiving antennas includes: an inverse matrix calculator operating as an inverse matrix calculation unit configured to calculate an inverse matrix of a matrix of the propagation path based on a signal received by a receiver; a detection speed controller operating as an estimation unit configured to estimate a variation in the propagation path over time; and a phase synchronization circuit and a regulator configured to variably control a processing time required to calculate the inverse matrix by the inverse matrix calculator, according to the variation in the propagation path over time estimated by the detection speed controller. The MIMO detector is provided on the side of the receiver of the wireless communication.

A method, system, and apparatus are provided for computing soft bits in a non-linear MIMO detector which decodes a signal received at a plurality of receive antennas using channel estimate information and a decoding tree to produce output data for a bit estimation value which includes a maximum likelihood solution along with a naturally ordered vector identifying all explored node metrics and node indices, where soft bits are computed for each bit estimation value by determining a set of bit-masks through repetition and indexing operations applied on the explored node indices, masking the naturally ordered vector with the set of bit-masks to generate masked node metrics, determining candidate soft bit values by subtracting metrics of all nodes that form the maximum likelihood solution from the masked node metrics, and determining a final soft bit value by identifying which of the candidate soft bit values has a lowest value.

The invention discloses a parking space vacancy guiding device, which comprises a parking space guiding card and parking space detectors, wherein the parking space guiding card comprises a shell body; a guiding card control circuit board, a guiding card storage battery and a guiding card wireless communication device are arranged inside the shell body, the top part of the shell body is provided with solar photovoltaic panels, and the front surface of the shell body is provided with LED indicating lamps and parking space digital displays; each parking space detector comprises a detector outer shell, and a detector control circuit board, a detector storage battery and a detector wireless communication device are arranged inside the detector outer shell; parking space indicating lamps and infrared ray detection devices are arranged on each detector outer shell; and the guiding card wireless communication device is connected with the detector wireless communication devices. The parking space vacancy guiding device has the advantages of being reliable in operation, saving energy and protecting environment, being easy to distinguish parking space vacancies, being convenient for people to park vehicles and the like, and has very high practical value.

The present invention discloses an integrated gamma spectrum measurement system suitable for neutron activation analysis, which includes a detector, a header multichannel pulse amplitude analyzer, aninterface and a shell. The detector includes a scintillator and a photomultiplier; and gamma ray enters the detector and is finally converted into an electric pulse signal. The header multichannel pulse amplitude analyzer is packaged by the metal shell, which includes a voltage divider circuit, an adjustable high voltage power circuit and a multichannel spectrum acquisition circuit. The voltage divider circuit and the adjustable high voltage power circuit provide the bias voltage for each dynode of the photomultiplier. The multichannel spectrum acquisition circuit realizes the conversion of the ray pulse signal to the spectrum. An interface circuit adopts a PoE interface, which can not only supply power for the system but also realize the function of network port communication. The shell plays a role of carrying, electromagnetic shielding and radiation shielding; and all components and circuits are enclosed in the detector shell. The invention provides the gamma spectrum measurement system with small volume, low cost, convenient application, a high counting pass rate and high energy resolution.

The invention discloses a mobile phone with an infrared imaging temperature measurement function and a temperature measurement method thereof. The mobile phone comprises a mobile phone main body. Themobile phone main body comprises a mobile phone panel and a mobile phone backboard. An installation space is formed between the mobile phone panel and the mobile phone backboard, and a main control element is accommodated in the installation space. An infrared imaging detector is arranged at the position, away from the main control element, of the installation space, and a thermal insulation material is arranged between the main control element and the infrared imaging detector. A vibration reduction buffer layer is wound outside the infrared imaging detector. The mobile phone backboard is provided with a detection port penetrating through the interior and exterior of the installation space, and the detection end of the infrared imaging detector directly faces the detection port. The edge,deviating from the installation space, of the detection port is filled with a damping layer. The infrared imaging detector is in communication connection with the main control element. The technicalscheme provided by the invention aims at solving the problem that the existing body temperature detection equipment cannot meet the daily temperature measurement requirements of people.

Systems and methods are disclosed that may detect data transmitted using MIMO communications. Data may be received, on a wireless channel, as a plurality of spatial streams. A channel matrix characterizing the wireless channel may also be received. The channel matrix may be decomposed into a first sub-channel matrix and a second sub-channel matrix, each having a lower dimension than the channel matrix. A first estimated data signal may be generated based at least in part on the plurality of spatial streams and the first sub-channel matrix. A second estimated data signal may be generated based at least in part on the plurality of spatial streams and the second sub-channel matrix. The first and second estimated data signals may be combined to recover the data.

A receiver and a receiving method for a Single Carrier Frequency Division Multiple Access (SC-FDMA) system are provided. The receiver includes a matrix selector for selecting a constant channel matrix according to a Multiple-Input Multiple-Output (MIMO) reception scheme, a channel equalizer for equalizing a multi-path channel to a specific path channel in a frequency domain by using the constant channel matrix, and a MIMO detector for detecting a Euclidean distance of transmittable symbols from a time-domain Transmit (Tx) signal by using the channel equalized in the frequency domain and then for selecting a symbol having a minimum distance.

The invention relates to a joint list detection and decoding method for fixing the complexity of a multiple input multiple output (MIMO) wireless communication system adopting block codes. The method comprises the following steps of: producing a candidate input code word list of a channel decoder from a candidate list of an MIMO detector by using a list generator so as to avoid iterative processing of a conventional detection and decoding algorithm; replacing soft decoding by hard decoding to reduce the working complexity of a receiving end; and joint processing is performed by using the list generator and the encoder to realize a uniform candidate character sequence space structure under joint constraint of an MIMO signal space and a code word space so as to improve system performance. The invention provides a new joint detection and decoding processing technical scheme which is used for the receiving end and designed by adopting the block codes in a channel coding scheme in the MIMO system. The method reduces calculation complexity and improves detection performance.

A multiple-input multiple-output (MIMO) receiver comprises a MIMO frequency-domain equalizer, which comprises a MMSE filter for mitigating inter-symbol interference and an adder for mitigating inter-antenna interference, a MIMO detector and a MIMO decoder for processing a received MIMO signal and for estimating transmit bits. The receiver comprises a feedback path from the decoder to the detector for providing soft-information on the transmit bits to the detector and an additional feedback path from the decoder to the MIMO frequency-domain equalizer for providing soft-information to the MMSE filter and to the adder of the equalizer.